GOLETA, Calif., Feb. 12 -- Cree Lighting Co., a wholly owned subsidiary of Cree Inc., said that it has demonstrated a near-UV/violet InGaN light emitting diode (LED) with a 32 percent quantum efficiency. According to Cree, this is the highest known external quantum efficiency publicly reported for a LED in the UV-to-blue portion of the wavelength spectrum and exceeds previous results demonstrated by Cree Lighting in July 2000 by 20 percent.
   The LED demonstrated emits at 390 nm and has a power output of 21 mW operating at 20 mA. LEDs in the UV and near-UV spectrum are essential for making efficient solid state white light sources. The LED light optically excites phosphors that emit white light. High quantum efficiency is critical to making these energy efficient sources. These results are a continuation of a collaborative R&D effort funded in part by the US Department of Commerce under the NIST Advanced Technology Program.
   "This result takes us beyond the 30 percent milestone in the UV-to-blue wavelength spectrum and brings us closer to the goal of a solid state product that can replace incandescent and fluorescent light sources," said Mike Dunn, vice president of Cree Lighting.