Researchers at Rensselaer Polytechnic Institute, United States, have developed a new method for manufacturing green-colored LEDs that results in significant enhancements in light extraction, internal efficiency and light output. The new technique involves etching a nanoscale pattern at the interface between the LED’s sapphire base and the layer of gallium nitride (GaN) that gives the LED its green color. According to Christian Wetzel, a professor of physics, “Green LEDs are proving much more challenging to create than academia and industry ever imagined. Every computer monitor and television produces its picture by using red, blue, and green. We already have powerful, inexpensive red and blue LEDs. Once we develop a similar green LED, it should lead to a new generation of high-performance, energy-efficient display and illumination devices. This new research finding is an important step in the right direction.” Wetzel said his new discovery should also be able to increase the light output of red and blue LEDs. The results of the study were published last week in the journal Applied Physics Letters.
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