Effect of the surface curvature of the phosphor layer on the optical performance of a WLED

In this study, the influence of the surface curvature of the phosphor layer on the optical performance of white light-emitting diodes (WLEDs) was investigated. Based on the lead frame of a standard 3528 component, WLEDs with various phosphor layer structures were fabricated for investigation. The curvature of the phosphor layer was adjusted by the volume of phosphor slurry. The consumption of phosphor materials was chosen as a control parameter for different structures in the present study. Both ray-tracing simulation and experimental investigations were performed to characterize the optical performance of the WLEDs. The relationship between the central height of the phosphor layer and the optical performance of WLEDs was analyzed in order to find the optimized structure.