http://cleanenergywiki.org/api.php?action=feedcontributions&user=Smhunter&feedformat=atom
CleanEnergyWIKI - User contributions [en]
2024-03-28T13:26:51Z
User contributions
MediaWiki 1.37.0
http://cleanenergywiki.org/index.php?title=Fluorometer&diff=8530
Fluorometer
2011-07-28T20:08:08Z
<p>Smhunter: </p>
<hr />
<div>=== Background ===<br />
[[Image:Fluorometer_layout.png|thumb|400px|Internal layout of fluorometer components- Fluorolog-3, model FL3-12 (Horiba Jobin Yvon) ]]<br />
A fluorometer consists of an excitation monochromator which directs light of specific wavelength on a sample. A fluorescent sample produces and emission spectrum that is measured through a monochromator connected to a photomultiplier detector similar to spectrophotometer.<br />
<br />
=== Significance ===<br />
[[Image:Fluor_cuvette.png|thumb|300px|Excitation and fluorescence of sample in cuvette]]<br />
'''Fluorescence quantum yield determination using relavitive method'''<br />
<br />
One significant use of the fluorometer (or fluorimeter) is the determination of the fluorescence quantum yield. This is done using a relative method based on a reference compound of known quantum yield. The unknown sample and the reference sample are measured at the same excitation wavelengths and measurement conditions. The wavelength-integrated fluorescent intensity of both materials are then used in the calculation:<br />
<br />
:<math>\phi = \phi_{reference} \frac {F_{sample} / A_{sample}} {F_{reference}/ A_{reference}} \left( \frac {n_{sample}} {n_{reference}} \right) ^2\,\!</math><br />
<br />
where<br />
<br />
&phi; is the quantum yield<br />
<br />
F= integrated fluorescence intensity<br />
<br />
A= absorbance at excitation wavelength<br />
<br />
n= refractive index<br />
<br />
'''Optically dilute solution'''<br />
<br />
The intensity of the excitation beam should be almost constant along excitation beam. The fluorescence signal is proportional to intensity of excitation beam and the intensity has to be the same for sample and reference.<br />
<br />
Typically: A ≤ 0.02 over 1 cm path length<br />
<br />
From entrance face to center of cuvette: A = 0.01<br />
<br />
T= 10<sup>-A</sup> = 10<sup>-0.01</sup>= 0.977<br />
<br />
Therefore the intensity has changed only by 2%<br />
<br />
However, depending on absorption spectrometer used, measurement of A in this range may not be accurate enough. How to proceed?<br />
*Measure A on higher concentration solution<br />
*Dilute solution by (accurately) known factor<br />
*Perform fluorescence measurement on diluted solutions<br />
<br />
'''Choice of excitation wavelength'''<br />
[[Image:Fluor_spectrum.png|thumb|300px| Excitation wavelength should be within the absorption band of the compounds<br />
]]<br />
<br />
The excitation wavelength should be within the absorption band of the compounds. The same excitation wavelength is used for reference and sample compounds. The emission spectrum is collected on the long wavelength side of the excitation wavelength (to avoid strong scattered light from excitation beam).<br />
<br />
In this test, we are using: &lambda;<sub>exc</sub> = 350 nm<br />
<br />
'''Repeated measurements'''<br />
<br />
Its always a good idea to have multiple data points! Prepare multiple dilutions and then measure fluorescence emission spectrum of each solution. Determine the slope of the line F/A for sample and reference. Deviations from linearity could indicate that emission was affected by reabsorption<br />
<br />
[[Image:Fluor_dilution.png|thumb|300px| Fluorescence intensity for various dilutions]]<br />
<br />
'''Reabsorption'''<br />
<br />
Reabsorption is the absorption of the emitted light by the same solution before light exits cuvette. This is more significant for compounds with small Stokes shifts. Reabsorption can appear as a redshift (or decrease in fluorescence intensity on the short wavelength portion of the spectrum). The effect can be minimized by reducing concentration of solution.<br />
<br clear='all'><br />
'''Corrected fluorescence spectra'''<br />
[[Image:Solvent_subtraction.png|thumb|500px| ]]<br />
Detectors and gratings do not have the same efficiency at all wavelengths. Therefore the results need to be corrected by a factor that accounts for wavelength response of the instrument. The contribution of the solvent (Raman scattering) and noise (dark counts) should also be subtracted.<br />
<br clear='all'><br />
<br />
'''Sample Calculation'''<br />
<br />
F/A values n<br />
<br />
Sample (#1): 1.289 x 10<sup>10</sup> cps/mA 1.3288 (methanol)<br />
<br />
Reference: 1.316 x 10<sup>10</sup> cps/mA 1.4266 (cyclohexane)<br />
<br />
&phi;<sub>reference</sub> = 0.87)<br />
<br />
:<math>\phi = \phi_{reference} \frac {F_{sample} / A_{sample}} {F_{reference}/ A_{reference}} \left( \frac {n_{sample}} {n_{reference}} \right) ^2\,\!</math><br />
<br />
<br />
:<math>\phi = 0.87 * \frac {1.289} {1.316} * \left( \frac {1.3288} {1.4266} \right) ^2\,\!</math><br />
<br />
=== Operation ===<br />
<br />
{{#ev:youtube|5edJlvxcxrY}}<br />
<br />
=== External Links ===<br />
[[Wikipedia:Fluorescence spectroscopy]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Femtosecond_Z-Scan_Spectrometer&diff=8513
Femtosecond Z-Scan Spectrometer
2011-07-11T21:28:26Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
=== Background ===<br />
The Femtosecond Z-Scan Spectrometer is used to measure extremely fast non-linear absorption and non-linear refraction. This is used to estimate the electro-optic coefficient and Kerr non-linearity.<br />
<br />
=== Significance ===<br />
'''Self Focusing or De-focusing'''<br />
<br />
[[Image:Selffocus.jpg|thumb|300px|As a third order materials passes through an focused light beam its index of refraction changes causing a focusing or defocusing of the beam.]]<br />
The closed aperture z-scan is based on the self-focusing effect. The index of refraction of a third order material changes as the intensity of the beam changes. As a sample through a focused beam the intensity of incident light increases to a point where the sample changes its index of refraction and alters the focus of the light. The width of the beam determines how much of the light passes through an aperture which can be measured with a simple detector.<br />
<br />
<br clear='all'><br />
'''Non linear Transmission'''<br />
[[Image:Nla.jpg|thumb|300px|Non linear absorption.]]<br />
<br />
Non-linear materials may also exhibit non-linear transmission or absorption meaning that as the intensity of the light pass through increases the transmittance decreases. For this measurement a lens is used (instead of an aperture) to collect all the light passing through the sample. This may be due to [[Two Photon Absorption|two photon absorption]] or other non-linear processes. The z-scan method can be used for non-fluorescent samples. This property is useful in developing protective goggles that have optical limiting. These would prevent extremely intense laser light from passing through.<br />
<br />
Sometimes samples exhibit both non-linear refraction and non-linear transmission. The self-focusing materials with high non-linearity of transmission would have curves that are distorted from those ideal ones presented above.<br />
<br />
<br clear='all'><br />
<div id="Flash">Z-Scan Spectrometer Simulation </div> <br />
<br />
In this simulation use the green bar to adjust the z position of the sample in the focused laser beam. The curve is representative of a material with a positive nonlinear refractive index; you'd get a curve with a mirror reflection of this for a negative refractive index material. <br />
<br />
<swf width="600" height="400">images/6/69/Z-scan.swf</swf><br />
<br />
=== Operation ===<br />
The laser beam passes through an [[optical parametric amplifier]] to select for a desired wavelength and then a pinhole [[spatial filter]] to limit eliminate transverse wave modes and attain a tight gaussian beam profile.<br />
<br />
{{#ev:youtube|nwrc33Zz3Zg}}<br />
<br />
=== External Links ===<br />
*[[wikipedia:Z-scan technique]]<br />
*[http://www.rp-photonics.com/z_scan_measurements.html Encyclopedia of Laser Physics and Technology]<br />
*[http://chemistry.asu.edu/laser/NewUser/Ultrafast%20%20Laser%20and%20Spectroscopy%20-%20UCSB.pdf Femtosecond Spectroscopy- UCSB]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=OFET_fabrication_and_characterization&diff=8511
OFET fabrication and characterization
2011-07-11T20:12:42Z
<p>Smhunter: </p>
<hr />
<div>===Background===<br />
The organic field effect transistor has a layered construction. A voltage applied to the gate causes the polymer layer to become a semiconductor and allows current flow between the source and drain contact.<br />
<br />
===Significance===<br />
<swf width=500 height=400>images/0/04/Ofet_roll_short.swf</swf><br />
<br />
All parts of an OFET can be made from plastics or thin flexible metals so that this could be used for flexible or printed electronics.<br />
<br />
[[Image:OFET-2Device_structures.jpg|thumb|left|500px|Solution processed and thermally evaporated OFET Device structures]]<br />
<br />
[[Image:Transfer_curve.png|thumb|400px|right| The OFET transfer curve showing source drain current in black and the squareroot of the source drain current in blue, plotted against the gate voltage. ]]<br />
<br clear='all'><br />
<br />
===Operation===<br />
{{#ev:youtube|PE8Att1iiFA}}<br />
<br />
===Links===<br />
see [[Organic_Field_Effect_Transistors]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Profilometer&diff=8152
Profilometer
2011-02-01T17:57:08Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
</tr><br />
</table> <br />
=== Overview ===<br />
<br />
A profilometer is an instrument that measures a surface's profile or roughness at the nanometer level. A contact profilometer has a diamond stylus that physically touches the surface. It is not sensitive to surface color or reflectance. Optical or non-contact profilometers scan the surface with light. <br />
<br />
<br />
<br />
<swf width="500" height="400">images/3/35/Profilometer.swf</swf><br />
<br />
=== Significance ===<br />
=== Technique ===<br />
'''A contact style profilometer'''<br />
<br />
{{#ev:youtube|uDSIm2mhyII}}<br />
<br />
<br />
'''A non-contact profilometer'''<br />
<br />
{{#ev:youtube|prUANnlQFFQ}} <br />
<br />
Video instructions for the [http://grover.mirc.gatech.edu/training/viewVideo.php?video=wyko-high&size=0 Wycko Profilometer at GT Microelectronics Research Center]<br />
<br />
=== Links ===<br />
<br />
see [[wikipedia:Profilometer]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Fourier_transform_infrared_spectroscopy_(FTIR)/Raman_spectroscopy&diff=8147
Fourier transform infrared spectroscopy (FTIR)/Raman spectroscopy
2011-01-25T18:19:12Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
</table><br />
<br />
<br />
=== Background ===<br />
This spectroscopic technique uses a Michelson interferometer to create an interferogram as an infrared source with many wavelengths is passed through a sample creating interference patterns as different wavelengths are differentially absorbed. The mathematical technique of Fourier transform is used to convert the raw signal into an recognizable absorption spectra like that produced by a UV/VIS spectrometer.<br />
<br />
<swf width="600" height="500">images/8/8b/FTIR.swf</swf><br />
<br />
=== Significance ===<br />
The advantage of FTIR over a standard dispersive spectrometer is that it can collect information across all wavelengths simultaneously yielding a better signal to noise ratio for a given scan time. It can use a broader beam of light because it is not passing it through the slit of a monochromator.<br />
<br />
<br />
=== Operation ===<br />
{{#ev:youtube|FdNkoj_QyeQ}}<br />
<br />
=== External Links ===<br />
<br />
see [[wikipedia:FTIR]]<br />
<br />
*[http://www3.wooster.edu/chemistry/analytical/ftir/default.html Wooster college FTIR animation]<br />
*[http://phet.colorado.edu/sims/fourier/fourier_en.jnlp PhET simulation on FT]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=NMR_spectrometer&diff=8141
NMR spectrometer
2011-01-24T21:35:53Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
</table><br />
<br />
=== Background ===<br />
[[Image:F3bb1f30c7.jpg|thumb|300px| ]]<br />
Nuclear magnetic resonance NMR spectroscopy is a sensitive chemical analytical technique which detects the magnetic properties of certain atoms such as hydrogen and carbon. The resulting spectrum can be compared against a database of known NMR signatures to identify atoms or functional groups in sample mixture. A typical application is to use NMR to prove that a sample pure or has completed a reaction.<br />
<br />
The following animation shows a single proton as it aligns to a strong magnetic field and then flips or precesses in an RF field. When the input RF is stopped the proton relaxes over a period of seconds and releases its energy in the form of an RF signal which is then recorded. The raw RF signal records the energy released by millions of protons located in different molecular environments. Fourier transform reduces the signal consisting of many resonant wavelengths down to distinct frequency spikes representing protons in different functional groups.<br />
<br />
<swf width="500" height="400">images/b/be/Nmr.swf</swf><br />
<br />
=== Significance ===<br />
Protons create different resonance spikes depending where they are located on the molecule. Non identical protons will exhibit individual peaks. But equivalent protons will couple to create a single stronger peak. <br />
<br />
[[Image:1H NMR Ethanol Coupling shown.GIF|thumb|left|300px| Calculated NMR showing coupling for ethanol ]]<br />
<br />
[[Image:1H NMR Ethyl Acetate Coupling shown.GIF|thumb|300px| Calculated NMR showing coupling for ethyl acetate]]<br />
<br clear='all'><br />
<br />
=== Operation===<br />
Bruker Icon NMR with Tanya David.<br />
{{#ev:youtube|BirHLLz3aXc}} <br />
<br />
<br />
<br />
This provides instructions for a Bruker Advance 300 NMR.<br />
<br />
Below is YouTube video from RSC<br />
<br />
{{#ev:youtube|uNM801B9Y84}}<br />
<br />
=== External Links ===<br />
<br />
*[[wikipedia:NMR_spectroscopy]]<br />
*[http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi Spectral database including HNMR]<br />
*[http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Spectrpy/nmr/nmr1.htm#nmr1 NMR primer William Reusch MSU]<br />
*[http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Spectrpy/nmr/nmr2.htm NMR primer part 2]<br />
*[http://en.citizendium.org/wiki/NMR_spectroscopy citizendium NMR article]<br />
*[http://www.chem.queensu.ca/FACILITIES/NMR/nmr/webcourse/list.htm NMR animations from Queens University]<br />
*[http://www.cis.rit.edu/htbooks/nmr/ Hornaks Basics of NMR ]<br />
*[http://vam.anest.ufl.edu/forensic/nmr.html NMR basics animation from U of Florida]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Superconducting_Quantum_Interference_Device-_SQUID&diff=8090
Superconducting Quantum Interference Device- SQUID
2010-12-07T22:34:06Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
</table><br />
<br />
=== Background ===<br />
SQUID is an extremely sensitive device used to measure the magnetic and paramagnetic properties of materials. The SQUID sensor consists of a superconducting circuit separated by a parallel Josephson junctions. The sensor is connected to a pickup coil inside a superconducting magnet. When the sample is moved inside the magnet and pickup coil this triggers an quantum interference pattern in the squid detector which causes voltage proportional to the change in magnetic flux caused by the sample. Thus extremely small magnetic properties are amplified into a measurable voltage.<br />
<br />
=== Significance ===<br />
In this animation you should notice the following:<br />
*The squid magnetometer is a superconducting loop connected to an pickup coil located inside a superconducting magnet.<br />
*When there is no magnetic flux, or change in magnetism the squid loop has superconducting current flow, but no voltage.<br />
*When a magnetic sample is moved in the pickup coil the loop is disrupted and a net voltage appears across the circuit.<br />
*The bias voltage is actually the voltage that is applied to cancel out the effects of the magnetic sample and maintain the superconducting loop.<br />
<br />
<swf width="500" height="400">images/7/75/Squid.swf</swf><br />
<br />
=== Operation ===<br />
<br />
{{#ev:youtube|Km2f4yzqXmQ}}<br />
<br />
=== External Links ===<br />
see [[wikipedia:SQUID]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:Field-Tdependence.png&diff=8083
File:Field-Tdependence.png
2010-11-29T22:21:35Z
<p>Smhunter: uploaded a new version of "File:Field-Tdependence.png"</p>
<hr />
<div>Neal Armstrong</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Physical_Vapor_Deposition_PVD_-_Vacuum/thermal_coater&diff=7988
Physical Vapor Deposition PVD - Vacuum/thermal coater
2010-10-21T23:45:41Z
<p>Smhunter: /* Operation */</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
</table><br />
<br />
=== Background ===<br />
Thermal vacuum coating is one the simplest and oldest of the physical vapor deposition techniques. A solid sample of material is heated in a vacuum and the particles that evaporate travel though the chamber and condense on the substrate.<br />
<swf width="400" height="400">images/4/44/Vacuumdep.swf</swf><br />
<br />
=== Significance ===<br />
Thermal evaporation vacuum coating is most often used for depositing metal or metal oxide contacts on flat substrates. It is difficult to control the thickness of the deposit and surface irregularities may cause shadows. The temperature of the source determines the speed of the atoms as they hit the substrate thus making it possible to limit damage to the substrate. This is a relatively rapid technique suitable for roll to roll processing.<br />
<br />
=== Operation ===<br />
{{#ev:youtube|f7UxBawRPj4}}<br />
<br />
=== External Links ===<br />
see [[wikipedia:Physical_vapor_deposition]]<br />
<br />
see [[wikipedia:Evaporation_(deposition)]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:DCV3T_triplets.JPG&diff=7978
File:DCV3T triplets.JPG
2010-10-13T19:59:36Z
<p>Smhunter: uploaded a new version of "File:DCV3T triplets.JPG":&#32;Corrected spelling and date of reference paper.</p>
<hr />
<div></div>
Smhunter
http://cleanenergywiki.org/index.php?title=Keys_to_Success_in_Graduate_School&diff=7959
Keys to Success in Graduate School
2010-10-08T18:47:36Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Professional Development for Research and Career Planning |Professional Development for Research and Career Planning ]]</td><br />
</tr><br />
</table><br />
<br />
==Keys to Success Videos==<br />
The following graduate student and post doc interviews were conducted at the national STC Director's meeting in Arlington VA, in September 2010.<br />
<br />
<br />
===Why graduate school?===<br />
*Is graduate school relevant to careers in industry as well as academia?<br />
*How do you use your existing job experiences (e.g., in a company or in an academic lab) to guide your decisions about graduate school?<br />
*When should you aim for a Masters degree, and when should your goal be a Ph.D.?<br />
*How can experience in a community college lead to persistence toward a Ph.D.? <br />
{{#ev:youtube|QssLE7KIjhg}}<br />
<br />
<br />
===How did you pick a graduate school?===<br />
*What practical considerations should one make with regard to potential doctoral programs and schools, thesis advisors and fellow graduate students? <br />
{{#ev:youtube|r6bnlN2_i8M}}<br />
<br />
<br />
===What about the first year of graduate school?===<br />
*What is a comprehensive exam? How is this exam unlike anything one experiences as an undergraduate?<br />
*What is doctoral candidacy and how does life change when you've achieved it?<br />
*What is the role of failure in being a graduate student?<br />
*How do you maintain your self esteem in the midst of increased academic competitiveness and risk of failure in graduate school?<br />
{{#ev:youtube|C64gGJWetFM}}<br />
<br />
<br />
===How do you pick a lab and advisor?===<br />
*How much consideration should you give to the prospective lab's level of equipment and its student culture, to the adviser's ability to maintain funding for graduate students, and to your ability to maintain the research themes you worked on as an undergraduate? <br />
{{#ev:youtube|SsSigVGIDh8}}<br />
<br />
<br />
===How do you pick a research topic?===<br />
*What's a Doctor of Philosophy degree anyway, and how does that degree represent the work you'll be doing as a scientist or engineer?<br />
{{#ev:youtube|GWJu-RAsIC8}}<br />
<br />
<br />
===What role does an STC play?===<br />
*What networking and collaboration opportunities to STCs afford?<br />
*How does the process of working with other lab members develop and enforce the knowledge you need to be a successful researcher?<br />
*What are the advantages and disadvantages of situating your graduate education in an interdisciplinary structure such as an STC?<br />
{{#ev:youtube|uAkre2qtk5c}} <br />
<br />
<br />
===What about mentoring?===<br />
* ...both your mentoring of others, and your being mentored by others?<br />
*Since research is a social pursuit, how does a shy individual cope with asking for the information he or she needs to be successful in the lab?<br />
*How does being female impact being a successful STEM graduate student? <br />
{{#ev:youtube|PIirU-EiQ68}}<br />
<br />
<br />
===Any other hints for success?===<br />
{{#ev:youtube|Kmm-ihFei4o}}<br />
<br />
<br />
== Links ==<br />
<br />
Here are some links that might help you succeed in College or Graduate School<br />
<br />
'''Undergraduate'''<br />
<br />
[http://www.cengagesites.com/academic/?site=4584&SecID=1657 Success factors from Cengage]<br />
<br />
<br />
'''Graduate'''<br />
<br />
[http://www.ece.rice.edu/~richb/resources.html Miscellaneous Graduate School links.]<br />
<br />
[http://www.career.ucf.edu/Students/Graduate_Students/Tips_for_Achieving_Success_in_Graduate_School_31_417.aspx Tips video from Central Florida]<br />
<br />
[http://www.dest.gov.au/archive/highered/hes/hes37/hes37.pdf Factor associated with completion Australian study]<br />
<br />
[http://www.imdiversity.com/Villages/Channels/grad_school/articles/grad_how_to_succeed.asp IMDiversity How to Succeed]<br />
<br />
[http://www.slideshare.net/gomap/how-to-succeed-in-graduate-school Sibrina Collins - understanding lingo]<br />
<br />
'''Post Doctorate'''<br />
<br />
[http://www.nationalpostdoc.org/ National Post Doctoral Association]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Keys_to_Success_in_Graduate_School&diff=7958
Keys to Success in Graduate School
2010-10-08T18:46:12Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Professional Development for Research and Career Planning |Professional Development for Research and Career Planning ]]</td><br />
</tr><br />
</table><br />
<br />
==Keys to Success Videos==<br />
The following graduate student and post doc interviews were conducted at the national STC Director's meeting in Arlington VA, in September 2010.<br />
<br />
===Why graduate school?===<br />
*Is graduate school relevant to careers in industry as well as academia?<br />
*How do you use your existing job experiences (e.g., in a company or in an academic lab) to guide your decisions about graduate school?<br />
*When should you aim for a Masters degree, and when should your goal be a Ph.D.?<br />
*How can experience in a community college lead to persistence toward a Ph.D.? <br />
<br />
{{#ev:youtube|QssLE7KIjhg}}<br />
<br />
===How did you pick a graduate school?===<br />
*What practical considerations should one make with regard to potential doctoral programs and schools, thesis advisors and fellow graduate students? <br />
<br />
{{#ev:youtube|r6bnlN2_i8M}}<br />
<br />
===What about the first year of graduate school?===<br />
*What is a comprehensive exam? How is this exam unlike anything one experiences as an undergraduate?<br />
*What is doctoral candidacy and how does life change when you've achieved it?<br />
*What is the role of failure in being a graduate student?<br />
*How do you maintain your self esteem in the midst of increased academic competitiveness and risk of failure in graduate school?<br />
{{#ev:youtube|C64gGJWetFM}}<br />
<br />
===How do you pick a lab and advisor?===<br />
*How much consideration should you give to the prospective lab's level of equipment and its student culture, to the adviser's ability to maintain funding for graduate students, and to your ability to maintain the research themes you worked on as an undergraduate? <br />
{{#ev:youtube|SsSigVGIDh8}}<br />
<br />
===How do you pick a research topic?===<br />
*What's a Doctor of Philosophy degree anyway, and how does that degree represent the work you'll be doing as a scientist or engineer?<br />
{{#ev:youtube|GWJu-RAsIC8}}<br />
<br />
===What role does an STC play?===<br />
*What networking and collaboration opportunities to STCs afford?<br />
*How does the process of working with other lab members develop and enforce the knowledge you need to be a successful researcher?<br />
*What are the advantages and disadvantages of situating your graduate education in an interdisciplinary structure such as an STC?<br />
{{#ev:youtube|uAkre2qtk5c}} <br />
<br />
===What about mentoring?===<br />
* ...both your mentoring of others, and your being mentored by others?<br />
*Since research is a social pursuit, how does a shy individual cope with asking for the information he or she needs to be successful in the lab?<br />
*How does being female impact being a successful STEM graduate student? <br />
{{#ev:youtube|PIirU-EiQ68}}<br />
<br />
===Any other hints for success?===<br />
{{#ev:youtube|Kmm-ihFei4o}}<br />
<br />
== Links ==<br />
<br />
Here are some links that might help you succeed in College or Graduate School<br />
<br />
'''Undergraduate'''<br />
<br />
[http://www.cengagesites.com/academic/?site=4584&SecID=1657 Success factors from Cengage]<br />
<br />
<br />
'''Graduate'''<br />
<br />
[http://www.ece.rice.edu/~richb/resources.html Miscellaneous Graduate School links.]<br />
<br />
[http://www.career.ucf.edu/Students/Graduate_Students/Tips_for_Achieving_Success_in_Graduate_School_31_417.aspx Tips video from Central Florida]<br />
<br />
[http://www.dest.gov.au/archive/highered/hes/hes37/hes37.pdf Factor associated with completion Australian study]<br />
<br />
[http://www.imdiversity.com/Villages/Channels/grad_school/articles/grad_how_to_succeed.asp IMDiversity How to Succeed]<br />
<br />
[http://www.slideshare.net/gomap/how-to-succeed-in-graduate-school Sibrina Collins - understanding lingo]<br />
<br />
'''Post Doctorate'''<br />
<br />
[http://www.nationalpostdoc.org/ National Post Doctoral Association]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Keys_to_Success_in_Graduate_School&diff=7957
Keys to Success in Graduate School
2010-10-08T18:44:46Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Professional Development for Research and Career Planning |Professional Development for Research and Career Planning ]]</td><br />
</tr><br />
</table><br />
<br />
==Keys to Success Videos==<br />
The following graduate student and post doc interviews were conducted at the national STC Director's meeting in Arlington VA, in September 2010.<br />
<br />
* Why graduate school?<br />
**Is graduate school relevant to careers in industry as well as academia?<br />
**How do you use your existing job experiences (e.g., in a company or in an academic lab) to guide your decisions about graduate school?<br />
**When should you aim for a Masters degree, and when should your goal be a Ph.D.?<br />
**How can experience in a community college lead to persistence toward a Ph.D.? <br />
<br />
{{#ev:youtube|QssLE7KIjhg}}<br />
<br />
* How did you pick a graduate school?<br />
**What practical considerations should one make with regard to potential doctoral programs and schools, thesis advisors and fellow graduate students? <br />
<br />
{{#ev:youtube|r6bnlN2_i8M}}<br />
<br />
* What about the first year of graduate school?<br />
**What is a comprehensive exam? How is this exam unlike anything one experiences as an undergraduate?<br />
**What is doctoral candidacy and how does life change when you've achieved it?<br />
**What is the role of failure in being a graduate student?<br />
**How do you maintain your self esteem in the midst of increased academic competitiveness and risk of failure in graduate school?<br />
{{#ev:youtube|C64gGJWetFM}}<br />
<br />
* How do you pick a lab and advisor?<br />
**How much consideration should you give to the prospective lab's level of equipment and its student culture, to the adviser's ability to maintain funding for graduate students, and to your ability to maintain the research themes you worked on as an undergraduate? <br />
{{#ev:youtube|SsSigVGIDh8}}<br />
<br />
* How do you pick a research topic?<br />
**What's a Doctor of Philosophy degree anyway, and how does that degree represent the work you'll be doing as a scientist or engineer?<br />
{{#ev:youtube|GWJu-RAsIC8}}<br />
<br />
* What role does an STC play?<br />
**What networking and collaboration opportunities to STCs afford?<br />
**How does the process of working with other lab members develop and enforce the knowledge you need to be a successful researcher?<br />
**What are the advantages and disadvantages of situating your graduate education in an interdisciplinary structure such as an STC?<br />
{{#ev:youtube|uAkre2qtk5c}} <br />
<br />
* What about mentoring?<br />
** ...both your mentoring of others, and your being mentored by others?<br />
**Since research is a social pursuit, how does a shy individual cope with asking for the information he or she needs to be successful in the lab?<br />
**How does being female impact being a successful STEM graduate student? <br />
{{#ev:youtube|PIirU-EiQ68}}<br />
<br />
* Any other hints for success?<br />
{{#ev:youtube|Kmm-ihFei4o}}<br />
<br />
== Links ==<br />
<br />
Here are some links that might help you succeed in College or Graduate School<br />
<br />
'''Undergraduate'''<br />
<br />
[http://www.cengagesites.com/academic/?site=4584&SecID=1657 Success factors from Cengage]<br />
<br />
<br />
'''Graduate'''<br />
<br />
[http://www.ece.rice.edu/~richb/resources.html Miscellaneous Graduate School links.]<br />
<br />
[http://www.career.ucf.edu/Students/Graduate_Students/Tips_for_Achieving_Success_in_Graduate_School_31_417.aspx Tips video from Central Florida]<br />
<br />
[http://www.dest.gov.au/archive/highered/hes/hes37/hes37.pdf Factor associated with completion Australian study]<br />
<br />
[http://www.imdiversity.com/Villages/Channels/grad_school/articles/grad_how_to_succeed.asp IMDiversity How to Succeed]<br />
<br />
[http://www.slideshare.net/gomap/how-to-succeed-in-graduate-school Sibrina Collins - understanding lingo]<br />
<br />
'''Post Doctorate'''<br />
<br />
[http://www.nationalpostdoc.org/ National Post Doctoral Association]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Keys_to_Success_in_Graduate_School&diff=7956
Keys to Success in Graduate School
2010-10-08T18:31:07Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Professional Development for Research and Career Planning |Professional Development for Research and Career Planning ]]</td><br />
</tr><br />
</table><br />
<br />
==Keys to Success Videos==<br />
The following graduate student and post doc interviews were conducted at the national STC Director's meeting in Arlington VA, in September 2010.<br />
<br />
* Why graduate school?<br />
**Is graduate school relevant to careers in industry as well as academia?<br />
**How do you use your existing job experiences (e.g., in a company or in an academic lab) to guide your decisions about graduate school?<br />
**When should you aim for a Masters degree, and when should your goal be a Ph.D.?<br />
**How can experience in a community college lead to persistence toward a Ph.D.? <br />
<br />
{{#ev:youtube|QssLE7KIjhg}}<br />
<br />
* How did you pick a graduate school?<br />
**What practical considerations should one make with regard to potential doctoral programs and schools, thesis advisors and fellow graduate students? <br />
<br />
{{#ev:youtube|r6bnlN2_i8M}}<br />
<br />
* What about the first year of graduate school?<br />
**What is a comprehensive exam? How is this exam unlike anything one experiences as an undergraduate?<br />
**What is doctoral candidacy and how does life change when you've achieved it?<br />
**What is the role of failure in being a graduate student?<br />
**How do you maintain your self esteem in the midst of increased academic competitiveness and risk of failure in graduate school?<br />
{{#ev:youtube|C64gGJWetFM}}<br />
<br />
* How do you pick a lab and advisor?<br />
**How much consideration should you give to the prospective lab's level of equipment and its student culture, to the adviser's ability to maintain funding for graduate students, and to your ability to maintain the research themes you worked on as an undergraduate? <br />
{{#ev:youtube|SsSigVGIDh8}}<br />
<br />
* How do you pick a research topic?<br />
**What's a Doctor of Philosophy degree anyway, and how does that degree represent the work you'll be doing as a scientist or engineer?<br />
{{#ev:youtube|GWJu-RAsIC8}}<br />
<br />
* What role does an STC play?<br />
**What networking and collaboration opportunities to STCs afford?<br />
**How does the process of working with other lab members develop and enforce the knowledge you need to be a successful researcher?<br />
**What are the advantages and disadvantages of situating your graduate education in an interdisciplinary structure such as an STC?<br />
{{#ev:youtube|OQEl070Z0lc}} <br />
* What about mentoring?<br />
** ...both your mentoring of others, and your being mentored by others?<br />
**Since research is a social pursuit, how does a shy individual cope with asking for the information he or she needs to be successful in the lab?<br />
**How does being female impact being a successful STEM graduate student? <br />
{{#ev:youtube|Dh9QMWCU3-s}}<br />
* Any other hints for success?<br />
{{#ev:youtube|2uIw5DsAkVI}}<br />
<br />
== Links ==<br />
<br />
Here are some links that might help you succeed in College or Graduate School<br />
<br />
'''Undergraduate'''<br />
<br />
[http://www.cengagesites.com/academic/?site=4584&SecID=1657 Success factors from Cengage]<br />
<br />
<br />
'''Graduate'''<br />
<br />
[http://www.ece.rice.edu/~richb/resources.html Miscellaneous Graduate School links.]<br />
<br />
[http://www.career.ucf.edu/Students/Graduate_Students/Tips_for_Achieving_Success_in_Graduate_School_31_417.aspx Tips video from Central Florida]<br />
<br />
[http://www.dest.gov.au/archive/highered/hes/hes37/hes37.pdf Factor associated with completion Australian study]<br />
<br />
[http://www.imdiversity.com/Villages/Channels/grad_school/articles/grad_how_to_succeed.asp IMDiversity How to Succeed]<br />
<br />
[http://www.slideshare.net/gomap/how-to-succeed-in-graduate-school Sibrina Collins - understanding lingo]<br />
<br />
'''Post Doctorate'''<br />
<br />
[http://www.nationalpostdoc.org/ National Post Doctoral Association]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=MediaWiki:Common.js&diff=7154
MediaWiki:Common.js
2010-06-22T21:35:30Z
<p>Smhunter: </p>
<hr />
<div>/* Any JavaScript here will be loaded for all users on every page load. */<br />
<br />
mwCustomEditButtons[mwCustomEditButtons.length] = {<br />
"imageFile": "http://depts.washington.edu/cmditr/mediawiki/images/a/aa/Button_sub_letter.png",<br />
"speedTip": "Subscript",<br />
"tagOpen": "<sub>",<br />
"tagClose": "</sub>",<br />
"sampleText": "Subscript Text"};<br />
<br />
mwCustomEditButtons[mwCustomEditButtons.length] = {<br />
"imageFile": "http://depts.washington.edu/cmditr/mediawiki/images/6/6a/Button_sup_letter.png",<br />
"speedTip": "Superscript",<br />
"tagOpen": "<sup>",<br />
"tagClose": "</sup>",<br />
"sampleText": "Superscript Text"};</div>
Smhunter
http://cleanenergywiki.org/index.php?title=MediaWiki:Common.js&diff=7153
MediaWiki:Common.js
2010-06-22T21:33:22Z
<p>Smhunter: Created page with '/* Any JavaScript here will be loaded for all users on every page load. */ mwCustomEditButtons[mwCustomEditButtons.length] = { "imageFile": "http://depts.washington.edu/…'</p>
<hr />
<div>/* Any JavaScript here will be loaded for all users on every page load. */<br />
<br />
mwCustomEditButtons[mwCustomEditButtons.length] = {<br />
"imageFile": "http://depts.washington.edu/cmditr/mediawiki/images/a/aa/Button_sub_letter.png",<br />
"speedTip": "Subscript",<br />
"tagOpen": "<sub>",<br />
"tagClose": "</sub>",<br />
"sampleText": "Subscript Text"};</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:Button_sub_letter.png&diff=7152
File:Button sub letter.png
2010-06-22T21:30:49Z
<p>Smhunter: </p>
<hr />
<div></div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:Button_sup_letter.png&diff=7151
File:Button sup letter.png
2010-06-22T21:30:35Z
<p>Smhunter: </p>
<hr />
<div></div>
Smhunter
http://cleanenergywiki.org/index.php?title=Band_Regime_versus_Hopping_Regime&diff=7140
Band Regime versus Hopping Regime
2010-06-22T20:19:49Z
<p>Smhunter: /* Band regime vs Hopping regime */</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Charge Carrier Mobility|Previous Topic]]</td><br />
<td style="text-align: center; width: 33%">[[Main_Page#Transport Properties|Return to Transport Properties Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Electronic Coupling| Next Topic]]</td><br />
</tr><br />
</table><br />
<br />
The '''band regime''' and '''hopping regime''' are the two limiting systems for transport although there are variations of each. They represent two ways that electricity can be conducted through an organic molecule or material.<br />
<br />
== Band regime versus Hopping regime ==<br />
In band regime the charge carrier (wave function) is delocalized over the entire molecule or system. The delocalization over the whole system means there is only a probability of finding the charge carrier in any location. This results in coherent transport. In a sense the charge carrier has a “memory” of where it was before.<br />
<br />
In hopping regime there is a localized charge carrier on a single molecule and you can follow the movement of the charge from molecule to molecule or chain segment to chain segment. Depending on the geometry and orientation of crystals hopping may result in differing mobilities in different directions or when hopping between layers. The band regime has the highest charge mobility and it is critical to understand the circumstances that encourage it. The transport is incoherent because each hop is random and has no correlation to the immediately preceding hop.<br />
<br />
'''Electronic coupling''' is large in the band regime and is the dominant factor. Whereas in the hopping regime coupling of charge carrier with vibrations, caused by geometry relaxations, is the dominant factor. In &pi; conjugated systems with a charge localized somewhere on a chain or a molecule there will be a geometry relaxation around that charge leading to the formation of a [[phonon]]. A '''phonon''' is a mode of vibration in an ordered solid material or molecular substance that involve then entire lattice.<br />
<br />
Geometry relaxations can lead to intramolecular vibrations as well as intermolecular vibrations in which adjacent molecules move with respect to one another.<br />
<br />
<br />
{| class="wikitable" border ="1"<br />
|- <br />
! band regime <br />
! hopping regime <br />
|- <br />
| delocalization of the charge carrier wave functions <br />
| localization of the charge carrier wave functions<br />
|- <br />
| coherent transport <br />
| incoherent hops <br />
|- <br />
| electronic coupling <br />
| electron-phonon coupling- <br />
<br />
leading to geometry relaxations <br />
*intramolecular modes<br />
*intermolecular modes.<br />
|} <br />
<br />
<br />
See Chemical Reviews 2004<ref>Chemical Reviews 104, 4971-5003 (2004)</ref><br />
<br />
See Chemical Reviews 2007<ref>Chemical Reviews 107, 926-952 (2007)</ref><br />
<br />
See Wikipedia [http://en.wikipedia.org/wiki/Organic_semiconductor Organic Semiconductor]<br />
=== Requirements for Band Regime ===<br />
<br />
In order to achieve a band regime (which has the largest carrier mobility) you must have a highly ordered structure or single crystal with few impurities. Low temperature is required because vibrations in adjacent coupled molecules due to temperature will decrease the electronic coupling and therefore decrease the mobility. For this reason mobility decreases with increasing temperature. In the case of methyl, which has a high charge carrier density, the decrease in mobility means the conductivity also decreases with temperature. The increase in intermolecular and intramolecular vibrations has generally a negative impact on the mobility of charge carriers.<br />
<br />
The second requirement for a band regime is the well ordered structure provides a large electronic coupling between adjacent sites on adjacent molecules or polymer repeat units. In a perfectly ordered polyacetylene the wave functions for the charge carriers are delocalized over the whole system. The presence of polarons and solitons means there must not be a perfect crystalline structure because these polaronic structures are associated with a geometry relaxation of the system. Charge polarons and solitons dissappear when there is complete delocalization. Polysulfur nitride ((SN)<sub>x</sub>) has crystals with strong interactions between the chains and no distortions. As a result there are no solitons. Normally samples of polyacetylene and transpolyacetylene are somewhat disordered and soliton and polaron behavior is observed.<br />
<br />
== Evidence for band regime vs hopping regime ==<br />
<br />
=== Time domain ===<br />
<br />
<br />
In the time domain the typical residence time t of a charge carrier on a site in a molecular materials or polymer repeat chain is described by an Heisenberg-like equation:<br />
<br />
:<math>\tau \approx \frac {\hbar} {W} \rightarrow \tau \approx \frac {2}{3} \frac {10^{-15}} {W_{(eV)}} S\,\!</math><br />
<br />
Where:<br />
:<math>\tau\,\!</math> is the residence time on a unit<br />
:<math>\hbar\,\!</math> is the period in the Heisenberg uncertainty principle equation<br />
:<math>W\,\!</math> is the bandwidth<br />
<br />
The wider the bandwidth the larger the electronic coupling between adjacent units. <br />
<br />
If W, the conduction bandwidth (for electrons) (and, or) the valance bandwidth (for holes) is large enough (.2-.3 eV) then &tau; is shorter than 10<sup>-13</sup> s and this means band transport is possible.<br />
<br />
This is because the carrier will not “sit” long enough on any single molecule for that molecule to have time to geometrically relax (relaxaton for C-C requires 20 ms) thus making band transport possible.<br />
<br />
In a simple tight-binding approximation: <br />
<br />
:<math>W = 4 \cdot t\,\!</math> <br />
<br />
where:<br />
:<math>t\,\!</math> is the electronic coupling between adjacent sites or adjacent repeating units. T is can also be called the transfer integral or the resonance integral &Beta;(in H&uuml;ckel terminology), or tunneling matrix element (in physics).<br />
<br />
=== Energy Domain ===<br />
<br />
There are two possibilities from an energy perspective. The charge carrier can fully delocalize along the system in which case there is no geometry relaxation and the energy gained by electronic coupling and charge carrier delocalization is larger than the energy gained by electron-phonon coupling (geometry relaxations around the charge) leading to charge carrier localization and polaron formation. In delocalization &pi; electrons from several isolated orbitals contribute to form a filled lower energy valence band and an empty higher energy conduction band. Thus the energy was lowered by delocalization. If the energy gained the electronic coupling and charge carrier delocalization is larger than the energy gained by electron-phonon coupling (geometry relaxations around the charge) leading to charge carrier localization and polaron formation, then the band regime is favored. In Marcus theory this is called minimizing the reorganization of the energy of the system.<br />
<br />
However if more energy is gained by geometry relaxation then the hopping regime is favored. <br />
<br />
In molecular materials we distinguish between intramolecular vibrations for instance the stretching of a C-C in a pentacene molecule (which is not not affected by adjacent molecules) and intermolecular vibrations (phonons) which propagate across an entire lattice.<br />
<br />
Lattice modes have frequency of 50-200 wavenumbers whereas intramolecular C-C stretch can have wavenumbers of 1500-1600. Phonon modes have 20-50 times less energy than intramolecular modes. As temperature in the system increases the phonon mode of vibration are the first to be excited. The frequency is lower so they are 20-50 times slower than a C-C bond stretch. In addition the higher temperature decreases the electronic coupling and increases localization.<br />
<br />
== References == <br />
<references/> <br />
[[category:transport properties]]<br />
<table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Charge Carrier Mobility|Previous Topic]]</td><br />
<td style="text-align: center; width: 33%">[[Main_Page#Transport Properties|Return to Transport Properties Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Electronic Coupling| Next Topic]]</td><br />
</tr><br />
</table></div>
Smhunter
http://cleanenergywiki.org/index.php?title=E-beam_Lithography&diff=7040
E-beam Lithography
2010-06-03T21:46:20Z
<p>Smhunter: </p>
<hr />
<div>=== Overview ===<br />
<br />
E-beam lithography is the process of directing an electron beam across a resist layer and thereby creating a pattern that can be etched. Structures of 20nm can be produced. This is the technique that is often used to create nano scale waveguides and microring resonators. One type uses an scanning electron microscope equipped with special beam control software. The other far more expensive method is a dedicated e-beam facility that is able to etch structures directly.<br />
<br />
[[Image:Si waveguide em.jpg|thumb|300px|Silicon waveguide in which EO polymers can be included]]<br />
<br />
<br />
See Wikipedia [http://en.wikipedia.org/wiki/Electron_beam_lithography E-beam lithography]<br />
<br />
=== SEM with Nabity ===<br />
The Nabity Nanometer Pattern Generation System (NPGS) combined with the Sirion SEM provides a user-friendly tool for the fabrication of nanostructures as small as 20 nm on a variety of materials including PMMA, SU8, and copolymers (MMA (8.5) and MMA EL 11). There are three basic steps involved in the generation of nano- or micro-scale patterns: (1) pattern design; (2) creation of a NPGS run file; and (3) pattern writing with alignment for multilayer lithography.<br />
<br />
#Patterns are created using DesignCAD and they may also be imported from DWG, DXF, GDSII, CIF, and IGES file formats.<br />
#An NPGS "run file" includes the exposure conditions for the different drawing elements in the pattern. Advanced features include global stage corrections, pattern arrays, x-y-focus, external commands, and fracturing of large patterns.<br />
#The NPGS identifies the writing (PG) and alignment (AL) programs in a "run file". PG writes a pattern by simultaneously controlling the x-y scan coils and beam blanking of the microscope. AL allows the alignment of patterns to existing alignment marks without exposing the writing area.<br />
<br />
[http://www.jcnabity.com/ JC Nabity website for SEM e-beam conversion]<br />
<br />
<br />
=== Operation ===<br />
<br />
Part 1:<br />
{{#ev:youtube|bvgITKqYpuY}}<br />
<br />
Part 2:<br />
{{#ev:youtube|fZmC5xeHHaw}}<br />
<br />
Part 3:<br />
{{#ev:youtube|ktkDqofYfMY}}<br />
<br />
<br />
=== Dedicated E-beam ===<br />
[http://www.microscopy-analysis.com/news/university-washington-orders-jeol-jbx-6300fs-direct-write-e-beam-lithography-system-microfabric UW order Jeol E-beam]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Main_Page&diff=7025
Main Page
2010-06-02T21:14:25Z
<p>Smhunter: /* Research Equipment, Devices and Techniques */</p>
<hr />
<div><big>'''Center for Materials and Devices for Information Technology Research (CMDITR) Wiki'''</big><br><br />
This wiki is a reference collection on research in photonics, organic electronics and organic photovoltaics. You must be logged in to edit this wiki. <br />
<br />
This wiki was created by the [http://stc-mditr.org Center for Materials and Devices for Information Technology Research] -NSF Grant #0120967<br />
<br />
If you would like to offer a correction or setup an editor account please contact:[mailto:education@stc-mditr.org?subject=CMDITRWikiRequest CMDITR Education]<br />
<br />
== Photonics Core Concepts and Applications ==<br />
[http://depts.washington.edu/cmditr/media/Photonics.html Concept Map CMDITR]<br />
<br />
[[Image:Wordle3.png|thumb|center|600px|This graphic was created by processing the CMDITR 2009 annual report in the Wordle program. The larger the word the more times it appeared in the text.]]<br />
<br clear='all'><br />
<br />
===Basics of Light ===<br />
[[Image:Snells_law_wavefronts.gif|thumb|150px|]]<br />
*[[Propagation, Reflection and Refraction]]<br />
*[[Dispersion and Scattering of Light]] <br />
*[[Diffraction of Light]]<br />
*[[Electromagnetic Radiation]]<br />
*[[Luminescence Phenomena]]<br />
*[[Color and Chromaticity]]<br />
<br />
<br clear='all'><br />
<br />
=== Optical Fibers, Waveguides, and Lasers ===<br />
[[Image:800px-Military_laser_experiment.jpg|thumb|200px|]]<br />
<br />
*[[Optical Fibers]]<br />
*[[Total Internal Reflection]]<br />
*[[Planar Dielectric Waveguides]]<br />
*[[Optical Fiber Waveguides]]<br />
*[[Dispersion and Attenuation Phenomena]]<br />
*[[Lasers]]<br />
<br />
===Molecular Orbitals===<br />
[[Image:HAtomOrbitals.png|thumb|150px|]]<br />
*[[Atomic Orbitals and Nodes]]<br />
*[[Electronegativity and Bonding Between Atoms]]<br />
*[[Sigma and pi Orbitals|Sigma and Pi Orbitals]]<br />
*[[Polarization and Polarizability]]<br />
*[[Electronic Coupling Between Orbitals]]<br />
*[[Donors and Acceptors]]<br />
<br clear='all'><br />
<br />
===Electronic Band Structure of Organic Materials===<br />
[[Image:Ethylene.JPG|thumb|200px|]]<br />
*[[Introduction to Band Structure]]<br />
*[[Electronic Structure of Hydrogen]]<br />
*[[The Polyene Series]]<br />
*[[Bloch's Theorem]]<br />
*[[Electrical Properties]]<br />
*[[Electronic States vs Molecular Levels]]<br />
<br clear='all'><br />
<br />
===Absorption and Emission of Light===<br />
[[Image:Abs Emis stokes.png|thumb|200px|]]<br />
*[[Introduction to Absorption]]<br />
*[[Changes in Absorption Spectra]]<br />
*[[Jablonksi Diagram]]<br />
*[[Fluorescence Process]] <br />
*[[Transition Dipole Moment]]<br />
*[[Absorption and Emission]]<br />
*[[Photochromism]]<br />
*[[Interchain Interactions]]<br />
<br />
<br clear='all'><br />
<br />
===Transport Properties===<br />
[[Image:rubrene.png|thumb|150px|]]<br />
*[[Charge Carrier Mobility]] <br />
*[[Band Regime versus Hopping Regime]]<br />
*[[Electronic Coupling]] <br />
*[[Model Calculations of Electronic Coupling]]<br />
*[[Marcus Theory and Reorganization Energy]] <br />
*[[Electron-Phonon Coupling]]<br />
<br />
<br clear='all'><br />
<br />
===Liquid Crystals and Displays===<br />
[[Image:smectic_C.jpg|thumb|200px|]]<br />
*[[Liquid Crystals]]<br />
*[[Double Refraction and Birefringence]]<br />
*[[Director – Degrees of Order in Liquid Crystals]]<br />
*[[Classification and Examples of Liquid Crystals]]<br />
*[[Alignment]]<br />
*[[Freederickz Transition and Dielectric Anisotropy]]<br />
*[[Liquid Crystal Displays]]<br />
<br />
<br clear='all'><br />
<br />
===Organic Light Emitting Diodes===<br />
[[Image:PNNL_Light_Lab_041.jpg|thumb|200px|Blue phosphorescent OLED developed by Pacific Northwest National Laboratory.]]<br />
*[[OLED Device Applications]]<br />
*[[Light Emitting Electrochemical Processes]]<br />
*[[The OLED Test Cell]]<br />
*[[What is a Light Emitting Diode?]]<br />
*[[The First OLEDs]]<br />
*[[Organic/Organic Heterojunctions in OLEDs]] <br />
*[[OLED Charge Mobilities]]<br />
*[[Organic Heterojunctions]]<br />
*[[Fluorescent/Phosphorescent Dopants]]<br />
*[[Metal Complex Dopants]]<br />
<br clear='all'><br />
<br />
===Organic Solar Cells===<br />
[[Image:Opvtestcells.png|thumb|200px|OPV Test Cells]]<br />
*[[Organic Solar Cells|OPV Introduction]]<br />
*[[Solar Technologies]]<br />
*[[Major Processes in Organic Solar Cells]]<br />
*[[Organic Heterojunctions in Solar Cells]]<br />
*[[Physics of Solar Cells]]<br />
*[[Energy vs Charge Transfer at Heterojunctions]]<br />
*[[Current OPV Research Directions]]<br />
<br clear='all'><br />
<br />
===Organic Electronics===<br />
*[[Organic Electronics Overview]]<br />
*[[Synthesis of Organic Semiconductors]](In progress)<br />
*[[Organic Field Effect Transistors]]<br />
*Design of n-type Semiconductors for Organic Electronic Applications<br />
<br />
==Non linear Optics and Devices==<br />
<br />
===Quantum Mechanical and Perturbation Theory of Polarizability===<br />
*[[Quantum-Mechanical Theory of Molecular Polarizabilities]]<br />
*[[Perturbation Theory]]<br />
<br />
===Second-order Processes, Materials & Characterization ===<br />
[[Image:MachZehnder.gif|thumb|200px]]<br />
*[[Second-order Processes]] <br />
*[[Structure-Property Relationships]]<br />
*[[Second-order NLO Materials]]<br />
*[[Second-order Material Design]]<br />
*[[Terahertz Radiation]]<br />
*[[Second-order Material Characterization]]<br />
<br />
<br clear='all'><br />
<br />
===Third-order Processes, Materials & Characterization ===<br />
[[Image:Tpa_concentrated.png|thumb|100px|]]<br />
*[[Introduction to Third-order Processes and Materials]]<br />
*[[Two Photon Absorption]]<br />
*Advanced Concepts in Third-order Processes<br />
*Characterization of Third-order Materials (Perry)<br />
<br clear='all'><br />
<br />
<br />
<br />
<br />
<br />
===Organic Photonics Applications in Information Technology ===<br />
[[Image:Dualmz packaged.png|thumb|200px|]]<br />
*[[Optical Networks]]<br />
*[[Passive Optical Polymers]]<br />
*[[Electro-optic Polymers and Devices]]<br />
*[[Materials Processing and Fabrication]]<br />
<br clear='all'><br />
<br />
===Photonics Integration===<br />
[[Image:Si_waveguide_em.jpg|thumb|200px|]]<br />
*[[The Need for Photonic Integration]]<br />
*[[Photonics Integration]] <br />
<br clear='all'><br />
<br />
== Research Equipment, Devices and Techniques ==<br />
<br clear='all'><br />
[[Image:PES.jpg|thumb|200px|]]<br />
'''Characterization'''<br />
*[[Photoelectron Spectrometer XPS and UPS]]<br />
*[[Conducting Tip Atomic Force Microscopy]]<br />
*[[Organic Photovoltaic Fabrication and Test Apparatus]]<br />
*[[Two-Photon Spectroscopy]]<br />
*[[Hyper Rayleigh Scattering]]<br />
*[[Scanning Electron Microscope]]<br />
*[[External quantum efficiency]]<br />
*[[Teng-Man Method]]<br />
*[[UV/VIS/NIR spectrometer]]<br />
*[[Attenuated Total Reflectance]]<br />
<br />
'''In Development'''<br />
*[[Profilometer]]<br />
*[[Ellipsometer]]<br />
*Fluorometer<br />
*NMR spectrometer<br />
<br />
*[[Transmission Electron Microscope]]<br />
*SPM<br />
*Raman microscope<br />
*[[confocal microsope]]<br />
<br />
'''Fabrication'''<br />
*[[E-beam Lithography]]<br />
*Reactive ion etcher<br />
*Plasma etcher<br />
*Atomic layer deposition<br />
*[[Spin coater]]<br />
*Sputter coater<br />
<br />
== General Research Best Practices ==<br />
*[[How to Keep a Lab Notebook]]<br />
*[[How to Give a Research Presentation]]<br />
*[[Writing a Scientific Paper]]<br />
*[[Writing a Successful Proposal]]<br />
*[[Mentoring]]<br />
*[[Responsible Conduct of Research- RCR]]<br />
*[[Career Planning]]<br />
<br />
==Acronyms and Unit Abbreviations==<br />
*[[Acronyms]]<br />
*[[Variables and Constants]]<br />
*[[Units]]<br />
<br />
==[[External Photonics Education Links]]==<br />
<br />
==K-12 Outreach Kits==<br />
[[Image:AssembledCell_small.JPG|thumb|200px|]]<br />
*[[K-12 Outreach Introduction]]<br />
*[[Basic Optics - Outreach Kit]]<br />
*[[Photovoltaics- Outreach Kit]]<br />
*[[Lasers and Telecommunication- Outreach Kit]]<br />
*[[Nanocrystalline - Dye Solar Cell Kit]]<br />
<br clear='all'><br />
<br />
==[[Suggested Wiki Sequence By Audience]]==<br />
<br />
== [[Photonics Wiki Showcase]] ==<br />
<br />
== [[Concept Map]] ==<br />
<br />
==[[Credits and Reviewers]]==<br />
{{Wikipedia|Solar Cells|Organic Photovoltaics}}<br />
[[w:Wikipedia|Wikipedia]]<br />
<br />
[[:en:{{{1}}}|Wikipedia: {{{2|{{{1}}}}}}]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Teng-Man_Method&diff=7023
Teng-Man Method
2010-06-02T21:12:39Z
<p>Smhunter: Teng-Mann Method moved to Teng-Man Method</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
=== Teng-Man Method for Measuring Electro-optic coefficient===<br />
[[Image:teng_mann.png|thumb|500px|Teng-Man Testing configuration]]<br />
The Teng - Man method can measure R<sub>33</sub> as the sample is being poled.<br />
R<sub>33</sub> is an elipsometric measurement<ref>http://en.wikipedia.org/wiki/Ellipsometry</ref>. A poling voltage is applied to the film while making the elipsometric measurements and looking for changes in the AC signal generated by incident light. The stage can be heated until the film reaches its melting point T<sub>g</sub>. These measurements are made with the materials in a device configuration. The formula for R<sub>33</sub><br />
<br />
:<math>r_{33}= \frac {3\lambda I_m } {4 \pi V_{poly}I_c n^2 } \frac {(n^2 - sin^2 \theta) ^{1/2}}{sin^2 \theta} \approx I_m/ I_c<br />
\,\!</math><br />
where<br />
<br />
:<math>I_m\,\!</math> is the amplitude of modulation<br />
:<math>V_{poly}\,\!</math> is the modulation voltage across EO polymer<br />
:<math>I_c\,\!</math> is the half intensity point<br />
:<math>n\,\!</math> is the refractive index of the polymer<br />
<br />
and<br />
<br />
:<math>V_{poly}= V_{ACtot} \frac {d_{poly}} {d_{poly} + d_{clad}} \cdot \sqrt {\frac {\epsilon_{clad}} {\epsilon _{poly}}}\,\!</math><br />
<br clear='all'><br />
<br />
[[Image:Teng_mann_data.png|thumb|500px|Data from Teng-Mann measurement]]<br />
<br />
The measured quanitities are:<br />
:<math>I= 2I_M\,\!</math> Modulated Intensity <br />
:<math>I_0 = 2I_C\,\!</math> Output intensity<br />
:<math>V_m = V_0 sin\omega t\,\!</math> Modulation Voltage<br />
<br />
<br clear='all'><br />
[[Image:Teng mann graph.png|thumb|400px|right|Real time optimization of r<sub>33</sub>]]<br />
<br />
Teng_Man techniques allows real-time optimization of processing conditions because you can evaluate r<sub>33</sub> during the poling process. It is used to confirm that a sample has been poled. The R33 measurement is best used as a relative measure because it can be inaccurate. Use attenuated total reflection ATR to get an accurate absolute measure.<br />
<br />
<br />
<br clear='all'><br />
See Khanarian 1996 <ref>Khanarian, et. al., JOSA B13, 1927 (1996)</ref><br />
<br />
See STC-MDITR research project 1.1 <ref>http://stc-mditr.org/research/oeoaomd/projects/1.111.cfm Measuring R33 with Interferometry</ref><br />
<br clear='all'><br />
<br />
=== Technique ===<br />
Part 1 Teng Man Setup<br />
{{#ev:youtube|5cy6q7FBs3Q}}<br />
<br />
Part 2 Teng Man Measurement<br />
{{#ev:youtube|-Q7PIoTmm0E}}<br />
<br />
=== Significance ===<br />
<br />
<br />
<br />
=== References ===<br />
<references/></div>
Smhunter
http://cleanenergywiki.org/index.php?title=Photoelectron_Spectrometer_XPS_and_UPS&diff=7022
Photoelectron Spectrometer XPS and UPS
2010-06-02T21:02:37Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
<br />
X-ray Photoelectron Spectroscopy and UV Photoelectron Spectroscopy are techniques for studying surface characteristics of materials.<br />
<br />
===Overview Physics of XPS and UPS===<br />
<br />
OLEDs and OPVs consist of thin films of organic materials, sandwiched between contacting electrodes. We need analytical tools which tell us:<br />
*Elemental composition of metal, metal oxide and organic surfaces (top 1-10 nm)<br />
*The molecular state of those elements in that same region<br />
*The frontier orbital energies which control rates of charge transfer, photopotentials, onset voltages, etc. see [[Work Function of Metals]]<br />
<br />
<br />
[[Image:Surface_electron_spectroscopies.jpg|thumb|right|300px |XPS uses high energy X-ray photons to excite “core” electrons in the near-surface region UPS uses lower energy photons in the deep UV region to excite valence electrons.]]<br />
We use high-vacuum surface electron spectroscopies: X-ray photoelectron spectroscopy (XPS)and UV-photoelectron spectroscopy (UPS) to provide the elemental, molecular and energetic information we require about these materials. Surface analysis is carried out in high vacuum spectrometers, with sophisticated sample handling capabilities. The sample is prepared in a chamber to which a variety of devices can be attached. The idea is to keep the surface as clean as possible, and to selectively add monolayers of organic materials to these surfaces, without the need to break vacuum between analyses. The sample is located at the center of the analytical chamber, and positioned so that we can excite it with either X-rays or UV photons. Once the photoelectrons are ejected from the sample, they are collected by a series of focusing lenses, and then separated according to their kinetic energy in a “hemispherical” analyzer. We use either a single “channeltron” detector (UPS) or a multi-channel detector(XPS)<br />
<br />
===Technique ===<br />
[[Image:PS-surfaceanalysis.jpg|thumb|right|300px |The small sampling depth of XPS and UPS arises because most of the photoelectrons generated do NOT make it out of the solid – they are scattered below the surface and not detected. Only those within 1-10 nm of the surface get out and can be analyzed.]]<br />
<br />
{{#ev:youtube|kK5OBNJwnws}}<br />
<br />
<br clear="all"><br />
<br />
===Significance===<br />
<gallery widths=300px heights=200px perrow=3> Image:Xps_spectrum.png|Here is a typical “survey spectrum” for a clean gold surface, modified with a single monolayer of a phenyl-terminated alkanethiol. We plot number of emitted photoelectrons on the y-axis, and their binding energy (BE) or kinetic energy (KE) on the x-axis. The photoelectric effect applies (as first described by Einstein) – there is conservation of energy, and you can see that the BE of each photoelectron is related to the excitation source energy, the measured kinetic energy of that photoelectron, and a “work function” of the spectrometer (constant). Each element provides us with at least one photoemission peak, with a distinct BE or KE. <br />
<br />
Image:Angle resolved xps.jpg|XPS is typically conducted with the sample perpendicular to the detector axis (normal takeoff angles) but if we want additional near-surface sensitivity we can tilt the sample. The above equation shows that tilting the sample gives us analytical information even closer to the surface <br />
<br />
Image:Angle resolved data.jpg|Spectra a,c and e are “normal takeoff” angle spectra of the O(1s) region from indium tin oxide surfaces that have been subjected to various pretreatments. Spectra b,d and f are from the same samples, with high takeoff angles of analysis, giving more near-surface information. In this case we see new peaks from hydroxyl (-OH) species located right at the surface of the oxide.<br />
<br />
Image:Xps_spectra.jpg|These high resolution XPS spectra show the power of the technique for the characterization of ITO surfaces with different PA modifiers. Note especially the C(1s) spectra region in (b) where we observe several different peaks due to carbon in its various forms within each molecule. The peak with a binding energy (BE) of ca. 285 eV is due to carbon in the backbone of the molecule, whereas higher BE peaks are seen for carbon bonded to fluorine (see the peaks at 291 and 293 eV for FHOPA). Similar molecular differences are seen in the O(1s) (a) P(2p) and In(4s) © and F(1s) spectral regions.<br />
<br />
Image: Ups_au_graph.jpg|Using UV photons as the excitation source we probe photoelectrons emitted from the valence band region of our materials of interest. Here for example is a UPS spectrum (He(I) excitation) for a clean gold surface. The regions of most interest are the high kinetic energy photoelectrons, and the energy where we begin to detect them (red line) and the low kinetic energy electrons and the lowest energy where they can be detected (blue line). The energy difference between these two threshold energies (w), subtracted from the source energy (21.2 eV) gives us an estimate of the effective surface work function of this material – in this case the work function for clean Au is about 5.1 eV.<br />
<br />
Image: Ups_au_plus_alkane.jpg|Now we have added a single monolayer of an alkane thiol modifier, which binds strongly to the Au surface, and changes the UPS spectrum, the effective work function of the Au surface. This modifier is a 12-carbon chain, terminated with a phenyl group, and we see a new ionization peak (orange) for the ionization of these phenyl groups. The width of the photoemission spectrum has changed as well, indicating a new work function for this modified Au surface.<br />
<br />
Image:Ups_fluoridated_alkanes.jpg|Now we see a series of UPS data for Au surface modified with alkanethiols of different lengths (from C3 to C18) (left panel) and a similar series of alkanethiols which are fluorinated at 1,2,4 and 10 positions along the chain (right panel). At the bottom of the screen we have schematically shown the orientation of the molecular dipole moments for these modifiers – the normal alkanes point the positive end of the dipole away from the surface, and lower the work function; the fluorinated alkanes point the negative end of the dipole away from the surface and increase the work function.<br />
<br />
Image:Workfunction_dipole.png|The presence of these surface modifiers either increases or decreases the energy of the low kinetic energy edge of the UV-photoemission spectrum, and these shifts correspond to changes in the effective surface work function of the conductor. Here we show that we can plot these changes in effective work function as a function of the molecular dipole moment of the modifier. The black squares correspond to self-assembled monolayers (SAMs) on gold (Au) surfaces, the red circles correspond to similar series of molecules on silver (Ag) surfaces, and the blue triangles correspond to a series of phosphonic acids attached to indium-tin oxide (ITO) surfaces. Note that the slopes of these plots are nearly the same, suggesting that the molecular dipole moment for the modifier is the most important attribute of these molecules. Note also that we can change the effective work function of these surfaces by up to ca. 1.8 eV!!<br />
<br />
</gallery><br />
[[category:Research equipment]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_4.2_Packaging_and_Processing_for_Printed_Electronics&diff=7010
Project 4.2 Packaging and Processing for Printed Electronics
2010-06-02T16:02:41Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 4.1 Organic Solar Cells and Integrated Modules|Project 4.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%"></td><br />
</tr><br />
</table><br />
<br />
A first objective of this project will be to develop thin film encapsulation layers with permeation rates at or below 10<sup>-5</sup> g/m<sup>2</sup>/day and to integrate them with organic photovoltaic cells, OLEDs, and organic circuits. Additional efforts to reduce the number of layers and processing steps needed for the encapsulation will be performed with goal of a single or bilayer encapsulation film. Finally, an understanding of the mechanics of the encapsulation film (adhesion, residual stress, etc.) and its impact on encapsulation reliability under flexure will also be addressed. Packaging research will focus simultaneously on providing good barriers to moisture and oxygen, and on characterizing and modeling their mechanical performance. A second objective of this project is to advance the science of processing techniques such as ink-jet printing that will enable the development of low cost, large area manufacturing processes based on organic and hybrid materials developed in the Center. <br />
<br />
<br />
{{#ev:youtube|PDbblXtblKc}} <br />
<br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/4/44/CMDITR101_Project4.2_Graham.pdf</embed_document><br />
<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/lsoe/projects.cfm</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_4.1_Organic_Solar_Cells_and_Integrated_Modules&diff=7008
Project 4.1 Organic Solar Cells and Integrated Modules
2010-06-02T16:01:55Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics|Project 3.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 4.2 Packaging and Processing for Printed Electronics |Project 4.2]]</td><br />
</tr><br />
</table><br />
<br />
The goal of our research on organic solar cells within CMDITR is to advance the understanding of the physics that governs their operation and to develop models that can be used to guide the optimization of their performance. These models also guide the synthesis of new materials for photovoltaic devices with optimized electrical and optical properties. Our objective will be to increase the efficiency of devices based on bulk heterojunctions and multilayer geometries (> 10% on glass substrates and > 7% on light-weight flexible substrates) by the synthesis of new molecules and polymers with optimized properties. Other important aspects of our activities include the study of the reliability of these devices and the development of new transparent conducting layers intended as replacements for ITO, which is expensive and has limited mechanical properties when deposited on flexible organic substrates. Another aspect of our research will be to understand the limiting factors when the area of the cells is increased and to develop means the materials and processes require to create high efficiency large-area cells and modules. One approach will also focus on building tandem cells, in which several cells based on organic films are stacked in the vertical direction. CMDITR’s long-term goal is to integrate a solar module with a rechargeable battery on a conformable substrate and to demonstrate portable sensor nodes (e.g. RFID tags) with increased functionality enabled by harvesting of ambient light.<br />
<br />
{{#ev:youtube|Sa4H4LUxd-4}}<br />
<br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/f/f4/CMDITR101_Project4.1_Armstrong.pdf</embed_document> <br />
<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/lsoe/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Organic Solar Cells|OPV Introduction]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_2.1_Materials_and_Devices_for_All-Optical_Switching_in_Integrated_Systems&diff=7007
Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems
2010-06-02T16:01:01Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 1.2 Materials and Devices for Terahertz Generation and Detection|Project 1.2]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics |Project 3.1]]</td><br />
</tr><br />
</table><br />
<br />
In order to develop polymers with sufficiently large third-order nonlinear susceptibility (χ<sup>(3)</sup>) for optical switching applications, CMDITR will refine current models that relate χ<sup>(3)</sup> to chemical structure. Specifically, CMDITR is developing materials with extensive delocalization beyond that which can be found in simple polymers, and with heightened optical nonlinearities arising from charge-transfer transitions. These approaches may yield materials with unprecedented performance at telecommunication wavelengths. In addition, CMDITR will investigate applications that take advantage of efficient twophoton absorption and third-harmonic generation. While ordering of chromophores is a well-understood key element in second-order nonlinear optical materials, the role of order in third-order nonlinear optical materials is poorly understood. Accordingly CMDITR will examine, both theoretically and experimentally, how chromophore ordering and aggregation can be used to significantly enhance χ<sup>(3)</sup>.<br />
<br />
{{#ev:youtube|3NNmnxeWPG0}} <br />
<br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/d/da/CMDITR101_Project2.1_Perry.pdf</embed_document> <br />
<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Introduction_to_Third-order_Processes_and_Materials]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_1.2_Materials_and_Devices_for_Terahertz_Generation_and_Detection&diff=7006
Project 1.2 Materials and Devices for Terahertz Generation and Detection
2010-06-02T16:00:31Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 1.1 EO and Spatial Light Modulators; Hybrid Integration with Silicon|Project 1.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems |Project 2.1]]</td><br />
</tr><br />
</table><br />
<br />
The bandwidth available from most commercial lasers today is around 3.5 THz because of limitations in the materials used for the emitter and detector (typically inorganic EO crystals such as ZnTe). By combining very short laser pulses with EO polymers, the entire 100-THz bandwidth, with no spectral gaps, can potentially be made available. This is of great interest from a security standpoint since accurate discrimination of chemical/biological agents and explosives requires spectroscopic capabilities in the 5-30 THz spectral range. Building on our successful demonstration of a wide bandwidth (> 12 THz) gapfree THz system based on EO polymers, CMDITR researchers are striving to utilize this advance to create a THz spectrometer that has an even wider bandwidth response (0-30 THz) and a brighter THz source. Successful implementation of such a system will require identification of materials with low absorption in that band, low group velocity dispersion (GVD), and very high EO coefficient (r33 preferably > 300 pm/V).<br />
<br />
{{#ev:youtube|p_0EOZYf40w}} <br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/e/ef/CMDITR101_Project1.2_Hayden.pdf</embed_document> <br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
[[Electromagnetic_Radiation]]<br />
<br />
[[Terahertz_Radiation]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_1.1_EO_and_Spatial_Light_Modulators;_Hybrid_Integration_with_Silicon&diff=7005
Project 1.1 EO and Spatial Light Modulators; Hybrid Integration with Silicon
2010-06-02T15:58:22Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%"></td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 1.2 Materials and Devices for Terahertz Generation and Detection |Project 1.2]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
To develop improved materials to modulate electrical and optical signals, CMDITR researchers work to:<br />
<br />
# Maximize bandwidth so that the material can carry as much information as possible;<br />
# Minimize the voltage required for device operation in order to minimize power consumption and heat generation; and<br />
# Minimize insertion loss and, therefore, signal degradation.<br />
<br />
In addition, CMDITR will strive to ensure that materials meet the practical requirements of facile processibility and resistance to physical, optical, and thermal fatigue. Stability has been dramatically enhanced by the development and implementation of new lattice-hardening chemistries. Theory, ranging from first-principles quantum-chemical approaches applied to molecular systems to statistical mechanics applied to understand the behavior of composite materials, plays an important role in guiding a rational design process for synthesizing the best candidate chromophores and for nanoengineering of material lattices. In parallel with materials development, CMDITR researchers utilize high-r33 EO materials to build novel high-speed modulators and organic/Si hybrid integrated devices.<br />
<br />
This project also seeks to efficiently incorporate nonlinear organic materials into silicon photonic devices through the use of strong nonlinear optical properties of organic materials for new frequency generation (sum and difference frequency generation, second and third harmonic generation) and up-converted fluorescence due to nonlinear absorption. Using this approach, CMDITR expects to achieve mode volumes that are 100 times smaller than what was believed to be possible in these systems, giving devices the potential to be 100 times more efficient.<br />
<br />
Part 1<br />
{{#ev:youtube|o5pct__5Bbs}} <br />
<br />
Part 2<br />
{{#ev:youtube|Jbq8X286O2I}} <br />
<br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/7/7b/CMDITR101_Project1.1_Jen.pdf</embed_document> <br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Electro-optic_Polymers_and_Devices]]<br />
<br />
[[The_Need_for_Photonic_Integration]]<br />
<br />
[[Second-order_Processes]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_3.1_Organic_and_Metal_Oxide_Field-Effect_Transistors_for_Flexible_Electronics&diff=6963
Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics
2010-06-01T15:54:14Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems|Project 2.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 4.1 Organic Solar Cells and Integrated Modules |Project 4.1]]</td><br />
</tr><br />
</table><br />
<br />
This project is focused on developing organic and metal oxide semiconductors with hole and electron mobility values > 10 cm²/Vs, well beyond those of amorphous silicon. High mobilities will be accomplished through optimizing the electronic coupling between electro-active groups, potentially achieving band-type transport, and through minimizing reorganization energy and the effects of phonons. At the same time, CMDITR will work on controlling the orientation of ordered materials with anisotropic mobilities (crystals, liquid crystals and crystalline polymers) so that the direction of maximum mobility can be aligned correctly for the device geometry of interest. CMDITR foresees that the development of surface-modifying agents will help with this issue, as well as improving adhesion at organic/organic and inorganic/organic interfaces. At the same time, CMDITR will tailor optical (absorption) and electronic (electron affinity and ionization potential) properties for specific device applications. CMDITR will also develop new dielectric materials that can be coated into thin (< 200 nm) filmswith high dielectric strength (> 2 MV/cm), low leakage current (<1 µA/cm²), and high capacitance density (> 50 nF/cm²). Materials development will be integrated with research on the fabrication, characterization, and modeling of the key building blocks of organic circuits, including diodes, transistors, inverters for digital circuit/logic circuits, circuit drivers for active-matrix displays, and transistor amplifiers for analog applications.<br />
<br />
{{#ev:youtube|Eue6i0GXLMY}} <br />
<br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/3/3f/CMDITR101_Project3.1_Wilson.pdf</embed_document> <br />
<br />
[[Media:CMDITR101_Project3.1_Wilson.pdf|Presentation Slides]]<br />
<br />
<br />
More information about this project can be found at:<br />
http://www.stc-mditr.org/research/lsoe/projects.cfm<br />
<br />
== Wiki Links ==<br />
[[Organic_Field_Effect_Transistors]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_2.1_Materials_and_Devices_for_All-Optical_Switching_in_Integrated_Systems&diff=6962
Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems
2010-06-01T15:53:59Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 1.2 Materials and Devices for Terahertz Generation and Detection|Project 1.2]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics |Project 3.1]]</td><br />
</tr><br />
</table><br />
<br />
In order to develop polymers with sufficiently large third-order nonlinear susceptibility (χ<sup>(3)</sup>) for optical switching applications, CMDITR will refine current models that relate χ<sup>(3)</sup> to chemical structure. Specifically, CMDITR is developing materials with extensive delocalization beyond that which can be found in simple polymers, and with heightened optical nonlinearities arising from charge-transfer transitions. These approaches may yield materials with unprecedented performance at telecommunication wavelengths. In addition, CMDITR will investigate applications that take advantage of efficient twophoton absorption and third-harmonic generation. While ordering of chromophores is a well-understood key element in second-order nonlinear optical materials, the role of order in third-order nonlinear optical materials is poorly understood. Accordingly CMDITR will examine, both theoretically and experimentally, how chromophore ordering and aggregation can be used to significantly enhance χ<sup>(3)</sup>.<br />
<br />
{{#ev:youtube|3NNmnxeWPG0}} <br />
<br />
<br />
<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/mediawiki/images/d/da/CMDITR101_Project2.1_Perry.pdf</embed_document> <br />
<br />
<br />
[[Media:CMDITR101_Project2.1_Perry.pdf|Presentation Slides]]<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Introduction_to_Third-order_Processes_and_Materials]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:CMDITR101_Project3.1_Wilson.pdf&diff=6961
File:CMDITR101 Project3.1 Wilson.pdf
2010-06-01T15:46:58Z
<p>Smhunter: Denise Wilson's talk at the 2010 CMDITR Retreat gives an overview of Center research in Project 3.1: organic and metal oxide field-effect transistors for flexible electronics. Denise Wilson is an Associate Professor of Electrical Engineering at the Univer</p>
<hr />
<div>Denise Wilson's talk at the 2010 CMDITR Retreat gives an overview of Center research in Project 3.1: organic and metal oxide field-effect transistors for flexible electronics. Denise Wilson is an Associate Professor of Electrical Engineering at the University of Washington.</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Conducting_Tip_Atomic_Force_Microscopy&diff=6894
Conducting Tip Atomic Force Microscopy
2010-05-13T16:18:05Z
<p>Smhunter: /* Operation */</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
=== Overview ===<br />
Atomic Force Microscopy (AFM)is a well established process for visualizing ultrafine surface characteristics. In normal AFM scanning mode a fine needle is drawn very near a surface and is gently bent by the various atomic forces. The conducting tip gives you the chance to measure electrical conductivity at discrete locations and then correlate these measurement with the surface scan that reveals the shape.<br />
<br />
see Wikipedia [http://en.wikipedia.org/wiki/Atomic_force_microscope Atomic Force Microscopy]<br />
<br />
<br />
=== Operation ===<br />
In C-AFM a metal-coated cantilever is moved back and forth across a sample’s surface. The vertical deflection of the cantilever is measured by monitoring the deflection of a laser beam reflected off the back of the cantilever, giving a topographic map of the surface. By applying a voltage to the tip and measuring the current flow we generate corresponding maps of sample topography and electrical properties. It is also possible to obtain current-voltage curves at a single point with an area of ~20 nm<sup>2</sup>.<br />
<br />
<swf width="640" height="452">http://depts.washington.edu/cmditr/media/afm.swf</swf><br />
<br />
This video is also available on YouTube:<br />
*[http://www.youtube.com/watch?v=H48w-aTE9pg AFM Video, Part 1]<br />
*[http://www.youtube.com/watch?v=RLardiQXruY AFM Video, Part 2]<br />
<br />
=== Significance ===<br />
This is of particular interest to the field of photonics research because the structure of thin coatings has a huge effect on the performance of devices.<br />
<br />
Application example from Alex Veneman at U of A.:<br />
<br />
Indium Tin Oxide (ITO) is the most commonly used anode in Organic Photovoltaics (OPVs) due to its optical transparency and relatively high electrical conductivity. ITO is an imperfect electrode, and electron transfer between the ITO and adjacent organic layers is hampered by heterogeneous coverage of surface contaminants and the fact that the oxide itself is most likely a heterogeneous mixture of phases with varying electrical properties. <br />
<br />
ITO for organic Light-Emitting Diodes (OLEDs) and OPVs is often treated by methods such as detergent or solvent cleaning, oxygen plasma or ozone cleaning and/or coating with poly(3,4-ethylenedioxythiophene) heavily doped with poly(styrenesulfonic acid) (PEDOT:PSS). The effect of these modifications at the nanoscopic level is still not fully understood, and although the effect of current-voltage properties of the devices has been studied, a working model describing their physical effects at the relevant length scales are lacking. In this work we use Conducting-Probe Atomic Force Microscopy (C-AFM) to study these surface modifications at the nanometer length scale, and compare these results to current-voltage data for macroscopic OPVs. <br />
<br />
Our results indicate that PEDOT:PSS is a ‘band-aid’ fix for the deeper problem of heterogeneity of the ITO surface. PEDOT:PSS electrically wires over ‘dead’ spots on the ITO, making an electrically uniform electrode, but it also introduces another energy barrier to the device that increases the diode quality factor and thus decreases fill factor. We also find that aggressive acid etching of the ITO surface results in increased homogeneity, and much improved repeatability in the manufacture of devices. <br />
<br />
[[Image:Itopics.png|thumb|500px|center|These C-AFM images demonstrate the electrical heterogeneity of the ITO surface. This lack of uniformity is due to carbonaceous impurities and hydroxide species contaminating the surface. Additionally it is unclear whether the ITO is composed of a single or multiple phases of varying electrical activity. Modification of the ITO surface can increase the electrical activity of the film by removing contaminant species and possible changing the relative ratio of phases present on the surface. <br />
]]<br />
<br />
[[Image:ITO-IVCURVE.png|thumb|600px|center|Each semi-log plot on the left shows current-voltage curves at several different ~20 nm2 areas on the same organic film. The data indicate that the electrical heterogeneity of the ITO affects the current flowing through the above Copper Phthalocyanine layer (top row). The addition of a PEDOT:PSS mediator layer (bottom row) makes the electrode electrically uniform by allowing current to pass over any insulating regions on the ITO surface. The PEDOT:PSS/CuPc interface is also rectifying in such a manner as to collect photocurrent and suppress dark current.<br />
It should also be noted that the acid etch produces a surface that is already very uniform and is actually hindered by the addition of the PEDOT:PSS layer (right column). <br />
]]<br />
[[category:Research equipment]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Organic_Photovoltaic_Fabrication_and_Test_Apparatus&diff=6890
Organic Photovoltaic Fabrication and Test Apparatus
2010-05-13T16:11:00Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
=== Overview ===<br />
It takes many trials to perfect the materials and techniques that make for highly efficient organic solar cells. This apparatus at University of Arizona combines a vacuum fabrication area with a inert gas glove box where prototype cells can be tested under controlled circumstance.<br />
<br />
The most common test is to generate a voltage vs current curve by experimentally varying the level of light used to excite the cell and by continually changing the load on the cell using a variable voltage power supply (reverse polarity). First a the cell is kept in the dark and a whole series of voltages are applied while the current is measured. Then this series of measurements is repeated while the cell is illuminated. Typical measurements open-circuit voltage (V<sub>oc</sub>), short-circuit current (I<sub>sc</sub>), fill factor (FF), maximum power output of the device (P<sub>max</sub>), voltage at maximum power (V<sub>max</sub>), current at maximum power (I<sub>max</sub>). A higher Fill Factor means that the cells is operating closer to its theoretical maximum efficiency.<br />
<br />
See wiki article on [[Physics_of_Solar_Cells]]<br />
<br />
=== Device Tour and Operation ===<br />
<br />
{{#ev:youtube|3kozKRTuZmg}}<br />
<br />
=== Significance ===<br />
One example of research using performance chararcterization is being being carried out by the Armstrong group at U of A.<br />
In this example variations of preparation of the ITO surface can be precisely compared.<br />
Poster: Characterizing and Modifying the ITO/Organic Interface: Organic Solar Cells<br />
<br />
[[Image:ITO-OPV.png|thumb|600px|center|The performance of organic photovoltaics can be drastically affected by the treatment the ITO receives. These treatments can change the ITO’s work function, remove carbon and/or hydroxides and change the relative ratio of In/Sn on the surface. This variability affects device repeatability and the performance of large-area devices<br />
]]<br />
[[category:Research equipment]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Organic_Photovoltaic_Fabrication_and_Test_Apparatus&diff=6889
Organic Photovoltaic Fabrication and Test Apparatus
2010-05-13T16:10:23Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
=== Overview ===<br />
It takes many trials to perfect the materials and techniques that make for highly efficient organic solar cells. This apparatus at University of Arizona combines a vacuum fabrication area with a inert gas glove box where prototype cells can be tested under controlled circumstance.<br />
<br />
The most common test is to generate a voltage vs current curve by experimentally varying the level of light used to excite the cell and by continually changing the load on the cell using a variable voltage power supply (reverse polarity). First a the cell is kept in the dark and a whole series of voltages are applied while the current is measured. Then this series of measurements is repeated while the cell is illuminated. Typical measurements open-circuit voltage (V<sub>oc</sub>), short-circuit current (I<sub>sc</sub>), fill factor (FF), maximum power output of the device (P<sub>max</sub>), voltage at maximum power (V<sub>max</sub>), current at maximum power (I<sub>max</sub>). A higher Fill Factor means that the cells is operating closer to its theoretical maximum efficiency.<br />
<br />
See wiki article on [[Physics_of_Solar_Cells]]<br />
<br />
=== Operation ===<br />
<br />
{{#ev:youtube|3kozKRTuZmg}}<br />
<br />
=== Significance ===<br />
One example of research using performance chararcterization is being being carried out by the Armstrong group at U of A.<br />
In this example variations of preparation of the ITO surface can be precisely compared.<br />
Poster: Characterizing and Modifying the ITO/Organic Interface: Organic Solar Cells<br />
<br />
[[Image:ITO-OPV.png|thumb|600px|center|The performance of organic photovoltaics can be drastically affected by the treatment the ITO receives. These treatments can change the ITO’s work function, remove carbon and/or hydroxides and change the relative ratio of In/Sn on the surface. This variability affects device repeatability and the performance of large-area devices<br />
]]<br />
[[category:Research equipment]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Teng-Man_Method&diff=6888
Teng-Man Method
2010-05-13T16:06:26Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
=== Teng-Man Method for Measuring Electro-optic coefficient===<br />
[[Image:teng_mann.png|thumb|500px|Teng-Man Testing configuration]]<br />
The Teng - Man method can measure R<sub>33</sub> as the sample is being poled.<br />
R<sub>33</sub> is an elipsometric measurement<ref>http://en.wikipedia.org/wiki/Ellipsometry</ref>. A poling voltage is applied to the film while making the elipsometric measurements and looking for changes in the AC signal generated by incident light. The stage can be heated until the film reaches its melting point T<sub>g</sub>. These measurements are made with the materials in a device configuration. The formula for R<sub>33</sub><br />
<br />
:<math>r_{33}= \frac {3\lambda I_m } {4 \pi V_{poly}I_c n^2 } \frac {(n^2 - sin^2 \theta) ^{1/2}}{sin^2 \theta} \approx I_m/ I_c<br />
\,\!</math><br />
where<br />
<br />
:<math>I_m\,\!</math> is the amplitude of modulation<br />
:<math>V_{poly}\,\!</math> is the modulation voltage across EO polymer<br />
:<math>I_c\,\!</math> is the half intensity point<br />
:<math>n\,\!</math> is the refractive index of the polymer<br />
<br />
and<br />
<br />
:<math>V_{poly}= V_{ACtot} \frac {d_{poly}} {d_{poly} + d_{clad}} \cdot \sqrt {\frac {\epsilon_{clad}} {\epsilon _{poly}}}\,\!</math><br />
<br clear='all'><br />
<br />
[[Image:Teng_mann_data.png|thumb|500px|Data from Teng-Mann measurement]]<br />
<br />
The measured quanitities are:<br />
:<math>I= 2I_M\,\!</math> Modulated Intensity <br />
:<math>I_0 = 2I_C\,\!</math> Output intensity<br />
:<math>V_m = V_0 sin\omega t\,\!</math> Modulation Voltage<br />
<br />
<br clear='all'><br />
[[Image:Teng mann graph.png|thumb|400px|right|Real time optimization of r<sub>33</sub>]]<br />
<br />
Teng_Man techniques allows real-time optimization of processing conditions because you can evaluate r<sub>33</sub> during the poling process. It is used to confirm that a sample has been poled. The R33 measurement is best used as a relative measure because it can be inaccurate. Use attenuated total reflection ATR to get an accurate absolute measure.<br />
<br />
<br />
<br clear='all'><br />
See Khanarian 1996 <ref>Khanarian, et. al., JOSA B13, 1927 (1996)</ref><br />
<br />
See STC-MDITR research project 1.1 <ref>http://stc-mditr.org/research/oeoaomd/projects/1.111.cfm Measuring R33 with Interferometry</ref><br />
<br clear='all'><br />
<br />
=== Technique ===<br />
Part 1 Teng Man Setup<br />
{{#ev:youtube|5cy6q7FBs3Q}}<br />
<br />
Part 2 Teng Man Measurement<br />
{{#ev:youtube|-Q7PIoTmm0E}}<br />
<br />
=== Significance ===<br />
<br />
<br />
<br />
=== References ===<br />
<references/></div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_1.1_EO_and_Spatial_Light_Modulators;_Hybrid_Integration_with_Silicon&diff=6863
Project 1.1 EO and Spatial Light Modulators; Hybrid Integration with Silicon
2010-05-04T21:42:39Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%"></td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 1.2 Materials and Devices for Terahertz Generation and Detection |Project 1.2]]</td><br />
<br />
</tr><br />
</table> <br />
<br />
To develop improved materials to modulate electrical and optical signals, CMDITR researchers work to:<br />
<br />
# Maximize bandwidth so that the material can carry as much information as possible;<br />
# Minimize the voltage required for device operation in order to minimize power consumption and heat generation; and<br />
# Minimize insertion loss and, therefore, signal degradation.<br />
<br />
In addition, CMDITR will strive to ensure that materials meet the practical requirements of facile processibility and resistance to physical, optical, and thermal fatigue. Stability has been dramatically enhanced by the development and implementation of new lattice-hardening chemistries. Theory, ranging from first-principles quantum-chemical approaches applied to molecular systems to statistical mechanics applied to understand the behavior of composite materials, plays an important role in guiding a rational design process for synthesizing the best candidate chromophores and for nanoengineering of material lattices. In parallel with materials development, CMDITR researchers utilize high-r33 EO materials to build novel high-speed modulators and organic/Si hybrid integrated devices.<br />
<br />
This project also seeks to efficiently incorporate nonlinear organic materials into silicon photonic devices through the use of strong nonlinear optical properties of organic materials for new frequency generation (sum and difference frequency generation, second and third harmonic generation) and up-converted fluorescence due to nonlinear absorption. Using this approach, CMDITR expects to achieve mode volumes that are 100 times smaller than what was believed to be possible in these systems, giving devices the potential to be 100 times more efficient.<br />
<br />
Part 1<br />
{{#ev:youtube|o5pct__5Bbs}} <br />
<br />
Part 2<br />
{{#ev:youtube|Jbq8X286O2I}} <br />
[[Media:CMDITR101_Project1.1_Jen.pdf|Presentation Slides]]<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Electro-optic_Polymers_and_Devices]]<br />
<br />
[[The_Need_for_Photonic_Integration]]<br />
<br />
[[Second-order_Processes]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:CMDITR101_Project1.1_Jen.pdf&diff=6862
File:CMDITR101 Project1.1 Jen.pdf
2010-05-04T21:41:05Z
<p>Smhunter: Alex Jen's presentation slides from the 2010 CMDITR Retreat gives an overview of Center research in Project 1.1: electro optic and spatial light modulators, and hybrid integration with silicon. Alex Jen is a Professor of Materials Science and Engineering </p>
<hr />
<div>Alex Jen's presentation slides from the 2010 CMDITR Retreat gives an overview of Center research in Project 1.1: electro optic and spatial light modulators, and hybrid integration with silicon. Alex Jen is a Professor of Materials Science and Engineering at the University of Washington.</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_1.2_Materials_and_Devices_for_Terahertz_Generation_and_Detection&diff=6861
Project 1.2 Materials and Devices for Terahertz Generation and Detection
2010-05-04T16:56:33Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 1.1 EO and Spatial Light Modulators; Hybrid Integration with Silicon|Project 1.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems |Project 2.1]]</td><br />
</tr><br />
</table><br />
<br />
The bandwidth available from most commercial lasers today is around 3.5 THz because of limitations in the materials used for the emitter and detector (typically inorganic EO crystals such as ZnTe). By combining very short laser pulses with EO polymers, the entire 100-THz bandwidth, with no spectral gaps, can potentially be made available. This is of great interest from a security standpoint since accurate discrimination of chemical/biological agents and explosives requires spectroscopic capabilities in the 5-30 THz spectral range. Building on our successful demonstration of a wide bandwidth (> 12 THz) gapfree THz system based on EO polymers, CMDITR researchers are striving to utilize this advance to create a THz spectrometer that has an even wider bandwidth response (0-30 THz) and a brighter THz source. Successful implementation of such a system will require identification of materials with low absorption in that band, low group velocity dispersion (GVD), and very high EO coefficient (r33 preferably > 300 pm/V).<br />
<br />
{{#ev:youtube|p_0EOZYf40w}} <br />
[[Media:CMDITR101_Project1.2_Hayden.pdf|Presentation Slides]]<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
[[Electromagnetic_Radiation]]<br />
<br />
[[Terahertz_Radiation]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:CMDITR101_Project1.2_Hayden.pdf&diff=6860
File:CMDITR101 Project1.2 Hayden.pdf
2010-05-04T16:54:20Z
<p>Smhunter: Michael Hayden's presentation slides from the 2010 CMDITR Retreat gives an overview of Center research in Project 1.2: materials and devices for terahertz generation and detection. Michael Hayden is a Professor of Physics at the University of Maryland, Ba</p>
<hr />
<div>Michael Hayden's presentation slides from the 2010 CMDITR Retreat gives an overview of Center research in Project 1.2: materials and devices for terahertz generation and detection. Michael Hayden is a Professor of Physics at the University of Maryland, Baltimore County.</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_2.1_Materials_and_Devices_for_All-Optical_Switching_in_Integrated_Systems&diff=6859
Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems
2010-05-04T16:08:32Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 1.2 Materials and Devices for Terahertz Generation and Detection|Project 1.2]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics |Project 3.1]]</td><br />
</tr><br />
</table><br />
<br />
In order to develop polymers with sufficiently large third-order nonlinear susceptibility (χ<sup>(3)</sup>) for optical switching applications, CMDITR will refine current models that relate χ<sup>(3)</sup> to chemical structure. Specifically, CMDITR is developing materials with extensive delocalization beyond that which can be found in simple polymers, and with heightened optical nonlinearities arising from charge-transfer transitions. These approaches may yield materials with unprecedented performance at telecommunication wavelengths. In addition, CMDITR will investigate applications that take advantage of efficient twophoton absorption and third-harmonic generation. While ordering of chromophores is a well-understood key element in second-order nonlinear optical materials, the role of order in third-order nonlinear optical materials is poorly understood. Accordingly CMDITR will examine, both theoretically and experimentally, how chromophore ordering and aggregation can be used to significantly enhance χ<sup>(3)</sup>.<br />
<br />
{{#ev:youtube|3NNmnxeWPG0}} <br />
[[Media:CMDITR101_Project2.1_Perry.pdf|Presentation Slides]]<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/oeoaomd/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Introduction_to_Third-order_Processes_and_Materials]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:CMDITR101_Project2.1_Perry.pdf&diff=6858
File:CMDITR101 Project2.1 Perry.pdf
2010-05-04T16:07:07Z
<p>Smhunter: Joe Perry's talk at the 2010 CMDITR Retreat gives an overview of Center research in Project 2.1: materials and devices for all-optical switching in integrated systems. Joe Perry is Professor of Chemistry and Biochemistry at Georgia Institute of Technology</p>
<hr />
<div>Joe Perry's talk at the 2010 CMDITR Retreat gives an overview of Center research in Project 2.1: materials and devices for all-optical switching in integrated systems. Joe Perry is Professor of Chemistry and Biochemistry at Georgia Institute of Technology.</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_3.1_Organic_and_Metal_Oxide_Field-Effect_Transistors_for_Flexible_Electronics&diff=6857
Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics
2010-05-04T16:05:37Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 2.1 Materials and Devices for All-Optical Switching in Integrated Systems|Project 2.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 4.1 Organic Solar Cells and Integrated Modules |Project 4.1]]</td><br />
</tr><br />
</table><br />
<br />
This project is focused on developing organic and metal oxide semiconductors with hole and electron mobility values > 10 cm²/Vs, well beyond those of amorphous silicon. High mobilities will be accomplished through optimizing the electronic coupling between electro-active groups, potentially achieving band-type transport, and through minimizing reorganization energy and the effects of phonons. At the same time, CMDITR will work on controlling the orientation of ordered materials with anisotropic mobilities (crystals, liquid crystals and crystalline polymers) so that the direction of maximum mobility can be aligned correctly for the device geometry of interest. CMDITR foresees that the development of surface-modifying agents will help with this issue, as well as improving adhesion at organic/organic and inorganic/organic interfaces. At the same time, CMDITR will tailor optical (absorption) and electronic (electron affinity and ionization potential) properties for specific device applications. CMDITR will also develop new dielectric materials that can be coated into thin (< 200 nm) filmswith high dielectric strength (> 2 MV/cm), low leakage current (<1 µA/cm²), and high capacitance density (> 50 nF/cm²). Materials development will be integrated with research on the fabrication, characterization, and modeling of the key building blocks of organic circuits, including diodes, transistors, inverters for digital circuit/logic circuits, circuit drivers for active-matrix displays, and transistor amplifiers for analog applications.<br />
<br />
More information about this project can be found at:<br />
http://www.stc-mditr.org/research/lsoe/projects.cfm<br />
<br />
== Wiki Links ==<br />
[[Organic_Field_Effect_Transistors]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_4.1_Organic_Solar_Cells_and_Integrated_Modules&diff=6856
Project 4.1 Organic Solar Cells and Integrated Modules
2010-05-04T16:05:12Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 3.1 Organic and Metal Oxide Field-Effect Transistors for Flexible Electronics|Project 3.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%">[[Project 4.2 Packaging and Processing for Printed Electronics |Project 4.2]]</td><br />
</tr><br />
</table><br />
<br />
The goal of our research on organic solar cells within CMDITR is to advance the understanding of the physics that governs their operation and to develop models that can be used to guide the optimization of their performance. These models also guide the synthesis of new materials for photovoltaic devices with optimized electrical and optical properties. Our objective will be to increase the efficiency of devices based on bulk heterojunctions and multilayer geometries (> 10% on glass substrates and > 7% on light-weight flexible substrates) by the synthesis of new molecules and polymers with optimized properties. Other important aspects of our activities include the study of the reliability of these devices and the development of new transparent conducting layers intended as replacements for ITO, which is expensive and has limited mechanical properties when deposited on flexible organic substrates. Another aspect of our research will be to understand the limiting factors when the area of the cells is increased and to develop means the materials and processes require to create high efficiency large-area cells and modules. One approach will also focus on building tandem cells, in which several cells based on organic films are stacked in the vertical direction. CMDITR’s long-term goal is to integrate a solar module with a rechargeable battery on a conformable substrate and to demonstrate portable sensor nodes (e.g. RFID tags) with increased functionality enabled by harvesting of ambient light.<br />
<br />
{{#ev:youtube|Sa4H4LUxd-4}}<br />
[[Media:CMDITR101_Project4.1_Armstrong.pdf|Presentation Slides]]<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/lsoe/projects.cfm<br />
<br />
== Wiki Links ==<br />
<br />
[[Organic Solar Cells|OPV Introduction]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:CMDITR101_Project4.1_Armstrong.pdf&diff=6855
File:CMDITR101 Project4.1 Armstrong.pdf
2010-05-04T16:04:47Z
<p>Smhunter: Neal Armstrong's talk at the 2010 CMDITR Retreat gives an overview of Center research in Project 4.1: organic solar cells and integrated modules. Neal Armstrong is a Professor of Chemistry and Optical Sciences at the University of Arizona.</p>
<hr />
<div>Neal Armstrong's talk at the 2010 CMDITR Retreat gives an overview of Center research in Project 4.1: organic solar cells and integrated modules. Neal Armstrong is a Professor of Chemistry and Optical Sciences at the University of Arizona.</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_4.2_Packaging_and_Processing_for_Printed_Electronics&diff=6854
Project 4.2 Packaging and Processing for Printed Electronics
2010-05-04T16:01:12Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 4.1 Organic Solar Cells and Integrated Modules|Project 4.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
<td style="text-align: right; width: 33%"></td><br />
</tr><br />
</table><br />
<br />
A first objective of this project will be to develop thin film encapsulation layers with permeation rates at or below 10<sup>-5</sup> g/m<sup>2</sup>/day and to integrate them with organic photovoltaic cells, OLEDs, and organic circuits. Additional efforts to reduce the number of layers and processing steps needed for the encapsulation will be performed with goal of a single or bilayer encapsulation film. Finally, an understanding of the mechanics of the encapsulation film (adhesion, residual stress, etc.) and its impact on encapsulation reliability under flexure will also be addressed. Packaging research will focus simultaneously on providing good barriers to moisture and oxygen, and on characterizing and modeling their mechanical performance. A second objective of this project is to advance the science of processing techniques such as ink-jet printing that will enable the development of low cost, large area manufacturing processes based on organic and hybrid materials developed in the Center. <br />
<br />
<br />
{{#ev:youtube|PDbblXtblKc}} <br />
[[Media:CMDITR101_Project4.2_Graham.pdf|Presentation Slides]]<br />
<br />
More information about this project can be found at: <br />
http://www.stc-mditr.org/research/lsoe/projects.cfm</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_4.2_Packaging_and_Processing_for_Printed_Electronics&diff=6850
Project 4.2 Packaging and Processing for Printed Electronics
2010-05-04T15:53:26Z
<p>Smhunter: Undo revision 6848 by Smhunter (Talk)</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 4.1 Organic Solar Cells and Integrated Modules|Project 4.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
</tr><br />
</table><br />
<br />
A first objective of this project will be to develop thin film encapsulation layers with permeation rates at or below 10<sup>-5</sup> g/m<sup>2</sup>/day and to integrate them with organic photovoltaic cells, OLEDs, and organic circuits. Additional efforts to reduce the number of layers and processing steps needed for the encapsulation will be performed with goal of a single or bilayer encapsulation film. Finally, an understanding of the mechanics of the encapsulation film (adhesion, residual stress, etc.) and its impact on encapsulation reliability under flexure will also be addressed. Packaging research will focus simultaneously on providing good barriers to moisture and oxygen, and on characterizing and modeling their mechanical performance. A second objective of this project is to advance the science of processing techniques such as ink-jet printing that will enable the development of low cost, large area manufacturing processes based on organic and hybrid materials developed in the Center. <br />
<br />
Part1<br />
{{#ev:youtube|PDbblXtblKc}} <br />
<br />
http://www.stc-mditr.org/research/lsoe/projects.cfm</div>
Smhunter
http://cleanenergywiki.org/index.php?title=File:CMDITR101_Project4.2_Graham.pdf&diff=6849
File:CMDITR101 Project4.2 Graham.pdf
2010-05-04T15:52:17Z
<p>Smhunter: Sam Graham's presentation slides from the 2010 CMDITR Retreat gives an overview of Center research in Project 4.2: packaging and processing for printed electronics. Sam Graham is Associate Professor of Mechanical Engineering at Georgia Institute of Techno</p>
<hr />
<div>Sam Graham's presentation slides from the 2010 CMDITR Retreat gives an overview of Center research in Project 4.2: packaging and processing for printed electronics. Sam Graham is Associate Professor of Mechanical Engineering at Georgia Institute of Technology.</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Project_4.2_Packaging_and_Processing_for_Printed_Electronics&diff=6848
Project 4.2 Packaging and Processing for Printed Electronics
2010-05-04T15:48:57Z
<p>Smhunter: </p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: left; width: 33%">[[Project 4.1 Organic Solar Cells and Integrated Modules|Project 4.1]]</td><br />
<td style="text-align: center; width: 33%">[[Suggested_Wiki_Sequence_By_Audience | Return Suggested Wiki Sequence By Audience Menu]]</td><br />
</tr><br />
</table><br />
<br />
A first objective of this project will be to develop thin film encapsulation layers with permeation rates at or below 10<sup>-5</sup> g/m<sup>2</sup>/day and to integrate them with organic photovoltaic cells, OLEDs, and organic circuits. Additional efforts to reduce the number of layers and processing steps needed for the encapsulation will be performed with goal of a single or bilayer encapsulation film. Finally, an understanding of the mechanics of the encapsulation film (adhesion, residual stress, etc.) and its impact on encapsulation reliability under flexure will also be addressed. Packaging research will focus simultaneously on providing good barriers to moisture and oxygen, and on characterizing and modeling their mechanical performance. A second objective of this project is to advance the science of processing techniques such as ink-jet printing that will enable the development of low cost, large area manufacturing processes based on organic and hybrid materials developed in the Center. <br />
<br />
<br />
{{#ev:youtube|PDbblXtblKc}}</div>
Smhunter
http://cleanenergywiki.org/index.php?title=UV/VIS/NIR_spectrometer&diff=6523
UV/VIS/NIR spectrometer
2010-03-04T19:05:12Z
<p>Smhunter: /* Operation */</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
</tr><br />
</table> <br />
<br />
=== Overview ===<br />
The spectrometer measures the optical absorption of light in several different spectral ranges.<br />
<br />
See Wikipedia on [http://en.wikipedia.org/wiki/Ultraviolet-visible_spectroscopy UV/VIS Spectroscopy]<br />
<br />
=== Operation ===<br />
UV/VIS Spectrometer Liquid Sample<br />
{{#ev:youtube|WFLcxxSuXiA}}<br />
<br />
UV/VIS Spectrometer Thin Film Sample<br />
{{#ev:youtube|Uivw6XkIc7w}}<br />
<br />
=== Significance ===<br />
<br />
[[category:research equipment]]</div>
Smhunter
http://cleanenergywiki.org/index.php?title=Attenuated_Total_Reflectance&diff=6522
Attenuated Total Reflectance
2010-03-04T19:03:36Z
<p>Smhunter: /* Technique */</p>
<hr />
<div><table id="toc" style="width: 100%"><br />
<tr><br />
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td><br />
=== Overview ===<br />
Attenuated Total Reflection or ATR is a technique used together with Teng Mann to measure the R33 of electro-optic materials. A beam of IR light is directed through a prism at an angle exceeding the critical angle for internal reflection. This produces an evanescent wave at the prism surface. If a EO polymer is pressed in intimate contact with the prism they can be coupled so that he evanescent wave stimulates emission from the sample. This emission is measured with a photodiode. An electric field applied to an EO polymer changes its index of refraction which alters the critical angle.<br />
<br />
=== Technique ===<br />
<div id="Flash">Attenuated Total Reflection simulation</div><br />
<br />
<swf width="720" height="480">http://depts.washington.edu/cmditr/media/atr.swf</swf><br />
<br />
The above simulation allows you visualize what is happening during ATR measurement.<br />
<br />
The EO material sample is pressed against the prism by the pneumatic plunger. The angle of the prism with respect to the laser is controlled with the slide bar. 0 degrees means the edge of the prism is normal to the laser beam and the sample is 45 degrees from the beam. <br />
<br />
The photodiode produces a current when there is reflection from the sample. At certain critical angles the sample traps light due to total internal reflection and its reflectance is attenuated.<br />
<br />
The field strength to the sample is controlled with the other slide 0-10 volts. This controls the EO effect in the sample.<br />
<br />
Click Auto graph to record the diode current and the sample lockin voltage across a range of angles from -12 to 0 ( -2800 to 0 microsteps). Repeat this measurement at various field strengths to see the effect on the diode current.<br />
<br />
<br />
Part 1<br />
{{#ev:youtube|2-Wc2QpLCa0}}<br />
<br />
Part 2<br />
{{#ev:youtube|P7BxIcl-9UM}}<br />
<br />
=== Significance ===<br />
The electro-optic coefficient for a poled polymer film can be calculated as follows<ref>J. Phys. Chem. C, 2008, 112 (21), pp 7983–7988<br />
DOI: 10.1021/jp712154g.</ref><br />
<br />
:<math>r_{33} = \frac {2d\Delta R} {n^3_{TM} V_m} \frac {\delta n_{eff}} {\delta \theta} \left /( \frac {\delta R \delta n_{eff} } {\delta \theta \delta n_{TM} } \right ) \,\!</math><br />
<br />
where<br />
:<math>R\,\!</math> is the DC reflected signal<br />
<br />
:<math>V_m\,\!</math> is the AC modulation voltage<br />
<br />
:<math>n_{eff}\,\!</math> is the ordinary index of refraction<br />
<br />
:<math>n_{TM}\,\!</math> is the film refractive index<br />
<br />
=== References ===<br />
<references/></div>
Smhunter