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Electroluminescence from organic polymers was discovered at the Cavendish Laboratory of Cambridge University in 1989, when it was found that 'organic' LEDs could be made using conjugated polymers. Researchers quickly realised the commercial potential of this discovery, especially for the manufacture of displays which emit their own light.
For a good overview of this subject, see: Introduction to PLEDs
P-OLEDs have a number of intrinsic advantages over liquid crystal devices:
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PLED is an emissive technology: it emits light as a function of its electrical operation; it therefore needs no backlight or colour filters.
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PLED technology is very energy efficient and lends itself to the creation of ultra-thin, light displays that will operate at lower voltages.
The resulting benefits include brighter, clearer displays with viewing angles approaching 180 degrees; simpler construction resulting in cheaper, more robust display modules, and fast response times allowing full colour video pictures even at low temperature.
The structure of a basic P-OLED display device can be extremely simple, consisting of a sandwich containing:
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A transparent electrode with a large work function. Indium tin oxide (ITO) is commonly used.
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A layer of PLED material less than 100nm thick.
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A metallic electrode with a low work function, typically calcium.
For an overview of how P-OLEDs work, see: How PLEDs work - Chemistry
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