Phosphor Converted White LED with Improved Efficiency

Abstract

Proposed short pass filter (SPF) employment to improve efficiency of phosphor converted white LED based on near UV LED dies and remote RGB phosphor architecture. SPF is transparent for near UV radiation in the 390-430 nm spectral range and possesses high reflectance for visual spectral range. SPF is placed between near UV LED and phosphor layer and redirects part of down warding white light to the outside of the package. Demonstrated 26 % average improvements for the conversion efficiency from 10.9 to 8.0 mW/Lm and 24 % average increase for luminous efficacy for 3000°K CCT and 85 CRI.