Researchers develop OLEDs with color temp spectrum of sunlight

Researchers at National Tsing Hua University in Taiwan have developed organic LEDs (OLEDs) with a full range of color temperatures capable of mimicking the full spectrum of sunlight throughout the day (2500 K - 8000 K), making the technology especially useful for lighting in northern countries.

“The sunlight-style OLEDs demonstrated here have a relatively simple design, consisting of layers just a few nanometers thick of various color-emitting materials, as well as an electron-transporting layer and an electron-injection layer. As the researchers explain, changing the voltage varies the color temperature by increasing the number of electrons and holes transported between certain layers. For example, at 3 volts, the illumination is predominantly red, at 5.5 volts it turns to pure white, and at 9 volts becomes bluish white.”

This sounds excellent, but OLEDs are not without their own challenges: the biggest of which is their relatively short life: Their color and light output degrades with time. However, one big advantage is that they don’t have the thermal problems of conventional LEDs, so it’s a promising field for lighting efficiency. The OLED industry predicts OLED lighting will hit the consumer market in 2015.