Cree Reports Laboratory Advances in High-Power LEDs

Caren B. Les

Cree Inc. of Durham, N.C., has achieved higher efficacy from packaged high-power LEDs. The results have been verified by the National Institute of Standards and Technology, based in Gaithersburg, Md. Tests conducted by the institute have confirmed that the cool-white (5813 K) LED has produced 135.7 lm of light output and achieved 129 lm/W efficiency, and that the warm-white (2950 K) LED has produced 104.2 lm of light output and achieved 99 lm/W efficiency. The institute tests LEDs at 350 mA and measures the output after five minutes of operation to ensure thermal stabilization

These research and development devices — not commercially available — incorporate advances in chip design and production, in epitaxial layers and in phosphor technologies. The company’s commercially available XLamp XR-E LEDs, on which the LEDS tested are based, are geared toward general illumination applications.