BBC: Researchers have demonstrated white, organic light-emitting diode (OLED) sources with the same efficiency as fluorescent light bulbs. The result brings closer the prospect that OLEDs will be the flat-screen light sources of choice in the future. The limited lifetime of the blue-emitting part of the devices means they survive for just hours, but new blue-emitting materials are on the horizon. The results are published in the journal Nature. There has been …