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One of the great benefits of an OLED display over the traditional LCD displays found in computer displays is that OLED displays don't require a backlight to function. This means that they draw far less power and they can be used with portable devices which mostly use monochrome low-resolution displays. This will also mean that they will be able to last for long periods of time with the same amount of battery charge.
The world's first digital camera with OLED display was the Kodak LS633 model revealed at the Photo Marketing Association (PMA) trade show in March 2003.
The key to the operation of an OLED is an organic dye. This dye has exciton states, which consist of an excited electron and a hole (empty state) it can fall into. When the electron and hole combine, a photon is emitted. The tricky part is the creation of the proper excitons. It can be done by shining light on the dye, which creates fluorescence. But the goal is to have a device that emits its own light.
To create the excitons, a thin film of the dye is used, and a current is passed through it in a special way. Excited electrons are injected into one side from a metal cathode, while holes are injected in the other from an anode (think of the anode as sucking electrons out of the dye). These electrons and holes move into the dye and meet to form excitons. Then when the excitons decay (the electron falls into the hole), they often give off the light we are looking for.
Derivatives of PPV, poly(p-phenylene-vynylene), are commonly used as the polymer dyes in OLEDs. Indium tin oxide is a common anode, while aluminum is a common cathode. Other materials are added in between the cathode/anode and the dye layer to enhance the efficiency.
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