Luminescence Phenomena - Revision history

Cmditradmin at 22:02, 19 August 2010

2010-08-19T22:02:33Z

← Older revision		Revision as of 15:02, 19 August 2010
Line 69:		Line 69:
	[[category:Light]]		[[category:Light]]
	[[category:Luminescence]]		[[category:Luminescence]]
			{{author
			\|AuthorFullName= Bredas, Jean-Luc
			\|AuthorName=Bredas}}
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>

Cmditradmin at 20:03, 29 December 2009

2009-12-29T20:03:49Z

← Older revision		Revision as of 13:03, 29 December 2009
Line 68:		Line 68:
	*red: Y<sub>2</sub>O<sub>2</sub>S : Eu, Tb (yttrium oxysulfide doped with europium and terbium)		*red: Y<sub>2</sub>O<sub>2</sub>S : Eu, Tb (yttrium oxysulfide doped with europium and terbium)
	[[category:Light]]		[[category:Light]]
	[[category:~~Luminesence~~]]		[[category:Luminescence]]
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>

Cmditradmin at 19:13, 29 December 2009

2009-12-29T19:13:20Z

← Older revision		Revision as of 12:13, 29 December 2009
Line 67:		Line 67:

	*red: Y<sub>2</sub>O<sub>2</sub>S : Eu, Tb (yttrium oxysulfide doped with europium and terbium)		*red: Y<sub>2</sub>O<sub>2</sub>S : Eu, Tb (yttrium oxysulfide doped with europium and terbium)
			[[category:Light]]
			[[category:Luminesence]]
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>

Cmditradmin at 17:07, 15 September 2009

2009-09-15T17:07:48Z

← Older revision		Revision as of 10:07, 15 September 2009
Line 27:		Line 27:
	:<math>E_1 - E_0\,\!</math> is the difference in energy from the excited state to a lower state.		:<math>E_1 - E_0\,\!</math> is the difference in energy from the excited state to a lower state.

	==~~=Luminescence vs phosphoresence=~~==		==Fluorescence==
	Within the luminescence processes there is also a distinction between two processes that occur after the excitation stops.		Within the luminescence processes there is also a distinction between two processes that occur after the excitation stops.

	*'''Fluorescence''' is luminescence that persists only on a time scale typical of the lifetime of the excited state. This is on the or der 10<sup>-9</sup> - 10<sup>-8</sup> seconds.		'''Fluorescence''' is luminescence that persists only on a time scale typical of the lifetime of the excited state. This is on the or der 10<sup>-9</sup> - 10<sup>-8</sup> seconds.

	*'''Phosphorescence''' is luminescence that persists for a longer period. Phosphorescence is usually related to the presence of metastable electronic state(s) E<sub>1</sub> itself or states with energy lower than E<sub>1</sub>.		== Phosphoresence ==

			'''Phosphorescence''' is luminescence that persists for a longer period. Phosphorescence is usually related to the presence of metastable electronic state(s) E<sub>1</sub> itself or states with energy lower than E<sub>1</sub>.

	===Activators and coactivators===		===Activators and coactivators===

Cmditradmin at 16:58, 15 September 2009

2009-09-15T16:58:41Z

← Older revision		Revision as of 09:58, 15 September 2009
Line 3:		Line 3:
	<td style="text-align: left; width: 33%">[[Electromagnetic Radiation\|Previous Topic]]</td>		<td style="text-align: left; width: 33%">[[Electromagnetic Radiation\|Previous Topic]]</td>
	<td style="text-align: center; width: 33%">[[Main_Page#Basics of Light\|Return to Basics of Light Menu]]</td>		<td style="text-align: center; width: 33%">[[Main_Page#Basics of Light\|Return to Basics of Light Menu]]</td>
	<td style="text-align: right; width: 33%">[[C\|Next Topic]]</td>		<td style="text-align: right; width: 33%">[[Color and Chromaticity\|Next Topic]]</td>

	</tr>		</tr>
Line 68:		Line 68:
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
			<td style="text-align: left; width: 33%">[[Electromagnetic Radiation\|Previous Topic]]</td>
			<td style="text-align: center; width: 33%">[[Main_Page#Basics of Light\|Return to Basics of Light Menu]]</td>
			<td style="text-align: right; width: 33%">[[Color and Chromaticity\|Next Topic]]</td>

	~~<td style="text-align: center; width: 33%">[[Main_Page#Luminescence and Color\|Return to Luminescence Menu]]</td>~~
	~~<td style="text-align: right; width: 33%">[[Electromagnetic Radiation\|Next Topic]]</td>~~
	</tr>		</tr>
	</table>		</table>

Cmditradmin at 16:54, 15 September 2009

2009-09-15T16:54:47Z

← Older revision		Revision as of 09:54, 15 September 2009
Line 1:		Line 1:
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
			<td style="text-align: left; width: 33%">[[Electromagnetic Radiation\|Previous Topic]]</td>
			<td style="text-align: center; width: 33%">[[Main_Page#Basics of Light\|Return to Basics of Light Menu]]</td>
			<td style="text-align: right; width: 33%">[[C\|Next Topic]]</td>

	~~<td style="text-align: center; width: 33%">[[Main_Page#Luminescence and Color\|Return to Luminescence Menu]]</td>~~
	~~<td style="text-align: right; width: 33%">[[Electromagnetic Radiation\|Next Topic]]</td>~~
	</tr>		</tr>
	</table>		</table>


	Light emitting plastics is one of the major applications of organic semiconductors. This involves the process of luminescence.		Light emitting plastics is one of the major applications of organic semiconductors. This involves the process of luminescence.

Cmditradmin at 16:42, 26 August 2009

2009-08-26T16:42:37Z

← Older revision		Revision as of 09:42, 26 August 2009
Line 9:		Line 9:

	Light emitting plastics is one of the major applications of organic semiconductors. This involves the process of luminescence.		Light emitting plastics is one of the major applications of organic semiconductors. This involves the process of luminescence.
	Luminescence is the process of light emission by a solid when given some form of energy. In order to provide visual information, materials are usually put in conditions that allow them to emit light. There are a several types of energy that can stimulate different molecules into an excited state.		Luminescence is the process of light emission by a solid when given some form of energy. In order to provide visual information, materials are usually put in conditions that allow them to emit light. There are a several types of energy that can stimulate different molecules into an excited state.
	===Types of Luminescence===		===Types of Luminescence===

Line 36:		Line 36:
	===Activators and coactivators===		===Activators and coactivators===
	In conventional inorganic “phosphors” that are used in conventional TV or computer displays much of the action is due to dopant or impurities within the host material known as activators. Activators are chosen to have electronic levels that are in the gap of the host material. This brings electrons from the valence band to the conduction band of the host. The electron then drops down from the conduction band into a forbidden or metastable state from where it gives of light in the form of phosphorescence.		In conventional inorganic “phosphors” that are used in conventional TV or computer displays much of the action is due to dopant or impurities within the host material known as activators. Activators are chosen to have electronic levels that are in the gap of the host material. This brings electrons from the valence band to the conduction band of the host. The electron then drops down from the conduction band into a forbidden or metastable state from where it gives of light in the form of phosphorescence.

	You can also have two different impurities known as an activator and co-activator. The activator has energy levels closer to the conduction band of the host and the coactivator has energy band closer to the valence band. The electron jumps from the activator to conduction band and then down to the coactivator energy band.		You can also have two different impurities known as an activator and co-activator. The activator has energy levels closer to the conduction band of the host and the coactivator has energy band closer to the valence band. The electron jumps from the activator to conduction band and then down to the coactivator energy band.

Cmditradmin at 16:38, 26 August 2009

2009-08-26T16:38:28Z

← Older revision		Revision as of 09:38, 26 August 2009
Line 8:		Line 8:


			Light emitting plastics is one of the major applications of organic semiconductors. This involves the process of luminescence.
	Light emitting plastics is one of the major applications of organic semiconductors. This involves the process of luminescence ~~phenonmena~~.		Luminescence is the process of light emission by a solid when given some form of energy. In order to provide visual information, materials are usually put in conditions that allow them to emit light. There are a several types of energy that can stimulate different molecules into an excited state.
	In order to provide visual information, materials are usually put in conditions that allow them to emit light. ~~Luminescence is the process of light emission by~~ a ~~solid when given some form~~ of energy.
	===Types of Luminescence===		===Types of Luminescence===

Cmditradmin: /* Cause of luminescence */

2009-08-24T17:36:42Z

Cause of luminescence

← Older revision		Revision as of 10:36, 24 August 2009
Line 22:		Line 22:

	===Cause of luminescence===		===Cause of luminescence===
	Whatever the source of excitation the final step is an electronic transition between two states of energy E1 and E0 with emission of a photon of a specific wavelength and color that depends on the energy levels.		Whatever the source of excitation the final step is an electronic transition between two states of energy E<sub>1</sub> and E<sub>0</sub> with emission of a photon of a specific wavelength and color that depends on the energy levels.

	:<math>h\nu = E_1 - E_0 = \frac{hc}{\lambda}\,\!</math>		:<math>h\nu = E_1 - E_0 = \frac{hc}{\lambda}\,\!</math>

Cmditradmin: /* Luminescence vs phosphoresence */

2009-06-11T17:35:42Z

Luminescence vs phosphoresence

← Older revision		Revision as of 10:35, 11 June 2009
Line 31:		Line 31:
	Within the luminescence processes there is also a distinction between two processes that occur after the excitation stops.		Within the luminescence processes there is also a distinction between two processes that occur after the excitation stops.

	'''Fluorescence''' is luminescence that persists only on a time scale typical of the lifetime of the excited state. This is on the or der 10<sup>-9</sup> - 10<sup>-8</sup> seconds.		*'''Fluorescence''' is luminescence that persists only on a time scale typical of the lifetime of the excited state. This is on the or der 10<sup>-9</sup> - 10<sup>-8</sup> seconds.

	'''Phosphorescence''' is luminescence that persists for a longer period. Phosphorescence is usually related to the presence of metastable electronic state(s) E<sub>1</sub> itself or states with energy lower than E<sub>1</sub>.		*'''Phosphorescence''' is luminescence that persists for a longer period. Phosphorescence is usually related to the presence of metastable electronic state(s) E<sub>1</sub> itself or states with energy lower than E<sub>1</sub>.

	===Activators and coactivators===		===Activators and coactivators===