Nano-patterning boosts LED efficiency (MAGAZINE)

Sept. 20, 2010
A variety of nano-patterning technologies can be used to enhance the light-extraction efficiency of LED chips, according to Ki Dong Lee, Robert Sjodin, and Torbjorn Eriksson.
The LED market is growing explosively, driven by widespread use in backlighting of LCD TVs and the potential replacement of incandescent and fluorescent lamps. The commercial success of LEDs has been relying on the ceaseless improvement in all aspects of LED technology spanning epitaxial growth, chip processing, and packaging.

LED efficiency measures the final light output for a given electrical input, and is determined by four factors: internal quantum efficiency, extraction efficiency, electrical efficiency and package efficiency. Internal quantum efficiency measures how many photons can be generated for given electron-hole pair generation, and is determined mostly by the quality of the epitaxial layer. Lightextraction efficiency defines how many photons of those generated can escape the LED device, and is determined by the chip and package structure.


This article was published in the September/October 2010 issue of LEDs Magazine. To read the full version of this article, please visit our magazine page, where you can download FREE electronic PDF versions of all issues of LEDs Magazine. You can also request a print copy of LEDs Magazine (available by paid subscription) and sign up for our free weekly email newsletter.