Violet Chip Excited White LEDs for Sun-Like Lighting and Horticulture Lighting

Abstract

With the latest progress in new generation of phosphor and packaging design, full spectrum, sun-like white LEDs become possible. We have developed such light sources by using a 410nm violet chip to excite a set of phosphors of blue, cyan, green and red, and then fine tune the spectrum power distribution (SPD). High color quality properties such as Ra of 98, Rg of 98 and Rf of 100 were achieved. With CCT of 5000K, it has an efficiency >105lm/W, a spectral continuity Cs >85 and low blue hazard ratio Br <40%. We also formulated spectra of LED by using a 410nm violet chip combined with a 450nm blue chip to excite cyan, green and red phosphors. High photosynthesis photo flux efficiency (PPE) of 2.35 umol/J was realized. These light sources are designed to mimic sun light to suit for both human centrical and horticulture lighting applications.