Investigation of Light Scattering Effect Impact on Optical Performance of Phosphor Converted White Light Emitting Diodes

Abstract

Phosphor-converted light emitting diodes (pc-WLEDs) have been a major approach to achieve white light for general lighting. Phosphor, serving as a color converter, plays an important role determining the chromatic and optical performance of WLEDs. Currently, two forms of phosphor, powdered phosphor and phosphor ceramic, are available. The powdered phosphor particles perform multiple scattering effect inside the encapsulant, while phosphor ceramics are transparent. It is important to understand the impact of scattering effect on the optical performance of WLEDs. In this study, based on a Monte-Carlo ray-tracing simulation, the optical performance including output radiant power and angular color uniformities (ACUs) of pc-WLEDs employing powder and ceramic based phosphors were simulated. The simulation results reveal the features of two types of WLEDs and the influence of scattering behavior on WLEDs. The outcome of the present study provides important reference to the LED packaging industrial field.