Scattering effect of SiO2 particles on correlated color temperature uniformity of multi-chip white light LEDs

Abstract

This study proposes the addition of SiO2 scattering particles into the phosphor layer of a multi-chip white light LED (MCW-LED) for enhancing its performance. It is demonstrated by computer simulations that SiO2 particles can bring significant effects on the correlated color temperature (CCT) uniformity and luminous flux. Through the simulation experiments, it was found that the MCW-LED with hybrid SiO2 structure with SiO2 particle size around 1 μm can achieve higher color uniformity than other package structures. We investigated the influence of SiO2 (quartz) concentration on the CCT and the output flux of the MCW-LED with CCTs 7000, 7700, and 8500 K, respectively. Compared to an LED package without SiO2, SiO2 packages can shrink the CCT deviation about 48%. In this study, it was demonstrated that the inclusion of about 5–10% SiO2 can produce an MCW-LED with higher CCT uniformity and optimal lumen output.