Mysterious cause of LED 'droop' identified, could lead to more efficient LED lights
LED Mystery solvedIf you increase the electrical current sent to a LED past a certain point, the amount of light produced will go down rather than up. This property of LEDs is called 'droop', and until recently scientists and engineers didn't know for sure why it happened. This made it hard to find a workaround, but now the riddle has been solved by a group of researchers from the engineering department of UC Santa Barbara and from CNRS-École Polytechnique in France. They have "conclusively identified Auger recombination as the mechanism that causes light emitting diodes (LEDs) to be less efficient at high drive currents."
© Michael Graham Richard
Knowledge gained from this study is expected to result in new ways to design LEDs that will have significantly higher light emission efficiencies. LEDs have enormous potential for providing long-lived high quality efficient sources of lighting for residential and commercial applications. The U.S. Department of Energy recently estimated that the widespread replacement of incandescent and fluorescent lights by LEDs in the U.S. could save electricity equal to the total output of fifty 1GW power plants. (source)
It's a very exciting time for LEDs, with prices dropping fast and new breakthroughs popping up in labs around the world. Hopefully multiples advances can be combined to make super-efficient LEDs. Can you imagine if Philips 200 lumens/watt white LEDs could be made more efficient with this droop discovery? This would make a big difference since all around the world lighting residential and commercial buildings accounts for a significant portion of all electricity used.