Color and illuminance uniformity enhancement of multi-chip white LEDs by complementing silica particles

Abstract

We analyze the influence of silica particle (SiO2) concentrations on color and illuminance uniformity of multi-chip white LEDs (MCW-LEDs) with a correlated color temperature (CCT) near 7700 K. It is suggested that the novel phosphor silicone layer (PSL), which added silica particles, can improve CCT and illumination uniformity. Using the commercial simulation program LightTools, based on Monte Carlo method, the novel PSL demonstrated a reduction of the CCT deviation (DCCT) to 1719 K from 2211 K, while the illuminance uniformity increased from 0.328 to 0.353. The simulation results could be totally convinced by Mie theory. This results point towards an approach for manufacturing high-quality MCW-LEDs.