oled, oleds

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OLED, OLEDs
Aufbau einer OLED

OLEDs are organic semiconductors based on several organic layers.
Usually on the anode (2) (e.g. Indium tin oxide (ITO)), which is on a glass pane (1), a hole conduct layer (3), (hole transport Layer or HTL) is applied.
Between ITO and HTL often, dependent on the production-process, still another layer with PEDOT/PSS (Poly(4-ethylendioxythiophen)/Polystyrolsulfonat)is applied.

This layer serves for the sinking of the injection barrier for the holes and preventes a "mixing" from indium into the junction.
On the HTL a layer is applied, which contains either the coloring material (approx. 5-10 %) or - rarely - completely of the coloring material (e.g. aluminum tris(8 hydroxychinolin), Alq3).
One calls this layer emitter layer (4), (emitter Layer, EL). On these an electron conduction layer (Electron transport Layer, ETL) is then applied.
At the end a cathode (5) consisting of a metal or an alloy with small electron emission function, as for example: Calcium, aluminum, barium, ruthenium, magnesium silver alloy in the high vacuum is vaporizated.
As protective layer and the decrease of the injection barrier for electrons mostly a very thin layer becomes from LiF, CsF or Ag vapour-deposited between cathode and ETL.
For more information over Oleds we recommend the web page: www.oled.at

Still there are television or computer screens much too thickly only actually to show points on the surface. The organic light emitting diodes need only an active layer of a ten thousandth millimeter!!!, two thin metallic contacts and a favorable substrate to reach the same brightness. The first organic displays are already available on the market and many further products will soon follow. Almost all considerable companies of the electronics industry work at present on organic display elements.

These organic layers are economically in the production and their color captivate with unique brilliance, also with diagonal view remain preserved!!! In addition, for illumination the Oled today already exceeds the usual bulb and approaches increasingly the fluorescent lamp.

Germany get´s the OLED-country:

In order to advance promising optical technologies in Germany, the Federal Ministry for education and research (BMBF) promotes the research and development of organic light emitting diodes (OLED) with 100 million euro by means of the next five years.
The enterprises involved want to invest 500 million euro in the context of the OLED initiative.

Up to 75% transparency planned:
The prototype of the transparent white OLED light-tile with the color coordinates 0.396/ 0.404 (CIEx/y main radiation pattern) shines on a surface of nearly 90 cm2!.
The transparency of the OLED is at present with 55%.
It is to be increased however in the context of the further development activities still on up to 75%.
The relationship of the jets in the two hemispheres can be adjusted in a large range. Thus it can be configured a surface source of light, e.g. in furniture or in a light sky in such a way that light radiates only in the desired direction. The results were obtained in the context of the CBM BF project OPAL2008 (Federal Ministry for education and research, organic light emitting diodes for lighting's applications).