OLED Device Applications

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Organic Light Emitting Diodes (OLEDs)are semiconductor devices that use organic compounds instead of silicon. Electricity is used to create an excited state in the compound which then loses energy in the form a photon emission as it returns to the ground state.

These products represent the fruition of 50 years of research, building first on the principles of silicon LEDS.

OLEDs are just are just beginning to appear in the commercial market. The first OLED devices include TVs, computer monitors, electronic control displays, cameras, phones, and lighting.

Advantages of OLEDs

Superior viewing angle- Monitors and TV screens are visible from side angles, unlike many LCD monitors.
Color Rendition- New dopants and dyes are being developed to give OLEDs a larger range and flexibility of color rendition.
Brightness- OLED pixels produce light rather than block light with polarizers as an LCD display does (100,000 cd/m²).
Faster Response- OLED devices have a typical response time of .01 ms compared to 2.0 ms for LEDs.
Energy Efficiency- The OLED is an efficient, low power consumpton, low heat light source.
Low cd drive voltage
Cost- New polymers and coatings will allow LEDs to be produced by printing and spin-coating techniques.
Flexibility- Polymer backing and thin coatings permit OLEDs to flex without breaking.
Thin / lightweight- An OLED display can be thin as a sheet of paper(< 1μm) .

Device Construction

An OLED consists of a thin transparent electrode, two or more organic transport/emitting layers, and a metal cathode. When power is applied to the electrodes light is emitted from the central layer.

Individual red, green and blue emitting OLEDs are arranged in a grid with individual power supplies for each pixel. This is called a passive display. This is being replaced with active thin film transistor displays that use a transistor to control each pixel. This is called an active matrix display.