The non direct Auger effect is the main cause of the decrease of the optical efficiency of the nitride based LED

Research Institute California University in Santa Barbara, said they found the fundamental reason for the inefficient use of LED general lighting. Their findings will help engineers to develop a new generation of high-performance, highly efficient lighting solutions to replace existing incandescent and fluorescent lamps.

Professor Van de Walle and his colleagues are working to improve the performance of highly efficient, non-toxic and long life nitride based LED. They further study under the drive of LED decay of this phenomenon in high power and long time. Has caused a lot of debate the reasons for this phenomenon, but researchers at the University of California in Santa Barbara say they use the quantum mechanical calculation method to find the formation mechanism of this phenomenon.

They concluded that LED decay (LED droop) by Auger recombination (Auger recombination) caused by. Auger recombination is a phenomenon that occurs in semiconductors, where three charged particles react with one another but do not emit photons. The researchers also found that the direct Auger effect is very significant. The discovery made in the previous theoretical study, using direct Auger process prediction does not match the LED decay and the actual measurement results can explain the phenomenon.

In the nitride based LED, these non direct processes form the main auger recombination. The first author published in the April 19th issue of the Journal of Applied Physics, California University of Santa Barbara postdoctoral researcher Emmanouil Kioupakis said. The other is the author of Van de Walle, Patrick Rinke, they Fritz in Germany, Haber Research Institute, Kris DELaney is a scientist at California University in Santa Barbara.

The researchers say, because the Auger effect is formed within the mechanism, so LED decay can not be eliminated, but can be minimized. The carrier density can be reduced by increasing the width of the quantum well and growing the device in the direction of polarization or polarization.

Take the lead of this research work, California University of Santa Barbara Department of materials Van de Walle said "found the problem is a prerequisite to solve. It is only after we find out that Auger recombination is the main reason can we focus on the innovative methods of inhibiting or avoiding this mechanism. "

The research was funded by the energy efficiency materials research center. High efficiency material research center is a U.S. Department of energy and the California University of Santa Barbara semiconductor lighting and energy center jointly funded. The calculation of the data used by the state of the U. S. Department of energy at work Vince Berkeley National Laboratory of energy research scientific computing center, California Institute of nano system located in California University of Santa Barbara computing center and the National Science Foundation Project TeraGrid.