northdenvernews.com
Improving LED efficiency at hand – Peak OIl
Researchers at the University of California, Santa Barbara, say they've figured out the cause of a problem that's made light-emitting diodes (LEDs) impractical for general lighting purposes. Their work will help engineers develop a new generation of high-performance, energy-efficient lighting that could replace incandescent and fluorescent bulbs. Identifying the root cause of the problem is an indispensable first step toward devising solutions, says Chris Van de Walle, a professor in the Materials Department at UC Santa Barbara who heads the research group that carried out the work. Van de Walle and his colleagues are working to improve the performance of nitride-based LEDs, which are efficient, non-toxic and long-lasting light sources. They investigated a phenomenon referred to as droop?the drop in efficiency that occurs in these LEDs when they're operating at the high powers required to illuminate a room. The cause of this decline has been the subject of considerable debate, but the UC Santa Barbara researchers say they've figured out the mechanism responsible for the effect by performing quantum-mechanical calculations.