Article Abstracts | January 2008
The complete article appears in the January 2008 issue of Photonics Spectra. If you do not have a copy of this issue,
e-mail us a request. Be sure to include your street address or fax number.
A New Material for Red LEDs
Yellow, amber and red InGaNP LEDs offer brightness,improved color and light-output stability with changing temperatures.
by Elliot Hicks, Quanlight
The general illumination market has seen the rapid evolution of white and blue LEDs, whereas yellow-, amber- and red-spectrum LEDs have lagged behind because they are plagued by issues of color stability and power efficiency. Traditionally, red LEDs have been composed of AlInGaP grown on a GaAs substrate. For high-brightness applications, the epilayer typically is transferred to a translucent GaP or mirrored substrate, allowing a larger portion of the light generated to be extracted.
In research conducted at the University of California, San Diego, InGaNP has shown promise for yellow, amber and red LEDs. The material has a larger-band offset than AlInGaP, and some successful initial tests have shown that InGaNP has the potential to make a brighter LED with a higher current density tolerance...
Start a discussion on this article or any photonics topic in the Photonics.com Community Forum