Meaglow Ltd., Thunder Bay ON, has shed new light on LED inefficiency thanks to the work of its research staff, together with students of the firm’s chief scientist, Dr. Butcher.
In a publication, now on line at the journal of Solid State Electronics vol. 103 (2015) 44, Meaglow staff and students of Lakehead University, have identified a significant parasitic current in one of the layers used for LEDs. This current does not contribute to light emission and therefore lowers LED efficiency. The current is due to background oxygen contamination in p-GaN layers. Three p-GaN templates bought commercially from different suppliers all had significant parasitic currents of this type.
The research shows that oxygen monitoring for MOCVD grown p-GaN and better quality control, are easy paths toward improved LED efficiency. The research also points to an opportunity for companies who have equipment that can provide in-situ monitoring of oxygen in p-GaN.
The recent publication has already appeared in some media sources, see for instance http://www.compoundsemiconductor.net/article/95421-a-new-source-of-gan-ingan-led-performance-limitation.html.
“In the long term, even modest efficiency improvements in nitride LEDs can ultimately lead to hundreds of millions, if not billions, of dollars in energy savings,” says Dr. Butcher. “Meaglow, is pleased to have done its part in making it a brighter and greener Christmas for everyone.”
Meaglow Ltd. produces a new range of epitaxy equipment, including custom built hollow cathode plasma sources for ALD equipment and other applications. These next generation plasma sources have been shown to provide lower oxygen and higher growth rates in many situations.