Stacked phosphor coating technology for white LEDs with high colour temperature and high colour rendering index

Abstract

Existing white LEDs use a blue LED chip to stimulate phosphor powder to form white light. The surface coated with a phosphor layer directly affects the colour rendering index, the luminous efficacy and the colour temperature. We have encapsulated a white LED source with chip-on-board packaging to meet the requirements for a high power, high colour temperature, high colour rendering index LED using stacked phosphor coating. This chip-on-board white LED light source can achieve a colour rendering index over 95 and a luminous efficacy over 100 lm/W while the colour temperature is 5700 K. This technology can be widely used in commercial lighting applications where high quality light sources are needed.