Solid-state lighting, using either organic or inorganic based light-emitting diodes (LEDs), is revolutionising the way we generate light for everything from back-lighting on your mobile phone to traffic signals and home-lighting.

The challenge in this area is to make organic LEDs (OLEDs) that can compete with existing light sources in efficiency, stability, colour quality and operation lifetime. Ching-Fong Shu of the National Chiao Tung University, Hsinchu, and colleagues have now created a white light OLED that fulfils several of these prerequisites. They combined a blue-emitting polymer with a green-emitting polymer and a red emitter to produce their promising device.