The incandescent lightbulb, synonymous with the inventions of Thomas Edison, has, until recently, been ever present since the late 19th century. In recent years such lightbulbs have been replaced gradually with the new energy saving technologies of fluorescent ligh bulbs and LEDs. However, just as semiconductor LEDs are becoming mainstream, owing to them now being able to produce warm white light having a spectrum similar to the incandescent bulb, a new type of LED may take their place.
Organic LEDs (OLEDs) contain a luminescent layer that is a film of an organic semiconductor compound that emits light in response to a current being passed through. As OLEDs can be manufactured with transparent electrodes, a whole panel can be manufactured that may then be illuminated to provide light over a large area. This contrasts with conventional lightbulbs (both incandescent, fluorescent and LED) whose light is emitted from a single location. This gives OLEDs much greater flexibility in how they can be incorporated into lighting displays but also furniture and buildings.
However, we might not be putting up OLED wallpaper just yet - the cost is currently approximately £5,000 per square metre. However within the next decade it is hoped that this cost will have been reduced drastically and OLEDs will be commonplace in our lives.
Conventional LEDs produce sharp points of light and cannot produce white light so LED bulbs usually mix different colours to approximate natural light but often do so with a blue tinge. In contrast, OLEDs emit a soft, diffuse light that's colour can be tuned to mimic natural light as closely as the old incandescent lamps. The technology provides fast switch-on times, wide operating temperatures and no noise.