Efficient White SSL Component for General Illumination

摘要

Cree has developed a new, high-efficiency, low-cost, light emitting diode (LED) module that should be capable of replacing standard, halogen, fluorescent and metal halide lamps based on the total cost of ownership. White LEDs are produced by combining one or more saturated color LEDs with a phosphor or other light down-converting media to achieve white broad-band illumination. This two year project addressed LED chip, package and phosphor efficiency improvements to establish a technology platform suitable for low-cost, high-efficiency commercial luminaires. New phosphor materials with improved quantum efficiency at real-life. operating conditions were developed along with new package technology to improve the efficiency of warm white LED modules compared to the baseline technology. Specifically, Cree has successfully demonstrated warm white LED modules providing 540 lumens at a correlated color temperature (CCT) of 3000 K. The LED module had an efficacy of 102.8 lumens per watt (LPW) using 1 mm2 chips biased at 350 mA a 27% improvement over the technology at project start (81 LPW at 3000K). The white modules also delivered an efficacy of 88 LPW at elevated junction temperatures of 125 degrees C.