White OLEDs Move Closer to Mass Market Reality

Sure, they work great for little laser pointers and traffic signals. But can organic light-emitting diodes (OLEDs) be developed to the point where they can replace conventional lighting? Scientists at the Molecular Foundry,  a U.S. Department of Energy nanoscience center located at Berkeley Lab,  and the University of California, Berkeley may have the answer–a thin film OLED using iridium-based guest molecules to emit various colors of visible light.

Single-color OLED displays are already available commercially, but OLEDs that produce luminous white light (the kind most of us prefer, outside of a dance club) are not. That’s because while white light (as we know) is simply a mix of red, green and blue light, when those colors mix in OLEDs they often interact with one another, degrading device performance and reducing color quality. The scientists at the Molecular Foundry appear to have found a way to use polymer nanoparticles to house the light-emitting ‘inks’ of OLEDs, which then serve to isolate molecules of different wavelengths from one another, resulting in the desired white luminescence.

Biwu_OLEDS_Berkeley

image via Berkeley Lab

“This simple and bright approach to achieving nanoscale site isolation of phosphors opens a new door for facile processing of white OLEDs for solid state lighting,” said Biwu Ma, a staff scientist with the Molecular Foundry’s Organic Nanostructures Facility, in a statement. It’s a breakthrough that could have real implications for the environment, as OLED are cheap and green and could greatly reduce electricity consumption if implemented on a large scale.

Susan DeFreitas has covered all manner of green technology for EarthTechling since 2009. She is a graduate of Prescott College for the Liberal Arts and the Environment, and has a background in marketing green businesses. Her work on green living has been featured in Yes! Magazine, the Utne Reader and Natural Home.