Red‐Emitting Cordierite Ceramic Enabling General Healthy Warm White Laser Lighting

Abstract

Abstract Laser‐driven phosphor‐converted white‐laser diodes are supposed to be next‐generation high‐brightness lighting sources for their unparalleled photoelectric efficiency and light quality, yet a significant obstacle hitherto has resided in the shortage and serious laser‐induced luminescence saturation of red emitters. Here, a hot‐pressing synthesis route to obtain high‐performance red‐emitting cordierite (Mg 2 Al 4 Si 5 O 18 :Eu 2+ ) ceramic is developed, which enables the in situ formation of bulk specimens with high crystallinity (>90%) from the counterpart glass powders. A preeminent saturation threshold of 21 W mm −2 is realized in a red‐emitting Mg 2 Al 4 Si 5 O 18 :Eu 2+ ceramic film converter. More importantly, the luminous exitance reaches 209 lm mm −2 , which is 5 times that of commercial red phosphor‐converted‐LED, indicating breakthrough progress in the comprehensive light‐emitting performance of red converters. This work innovates the solid‐state synthesis of laser bulk converters from glass to meet the demanding requirements of advanced warm white laser lighting.