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

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 (Mg2Al4Si5O18:Eu2+) 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 Mg2Al4Si5O18:Eu2+ 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.

Ce:(Lu,Sr)3(Al,Si)5O12 transparent ceramics for high-power white LEDs/LDs with ultra-high luminance saturation threshold

“…White light emitting diodes or laser diodes (WLEDs/WLDs) have attracted significant attention for their environmentally friendly nature, small volume and long service life. 1–16 Currently, the main method for constructing WLEDs/WLDs is to combine a blue LED/LD chip or a blue laser source with a Ce 3+ :Y 3 Al 5 O 12 (Ce:YAG) material. 17,18 However, phosphors encapsulated by the traditional organic resin have low thermal conductivity (0.1–0.4 W m −1 K −1 ), and are easy to burn or carbonize at high temperatures, which are not suitable for high power LED or LD lighting.…”

High-Efficiency Mn4+-Doped Rb2GeF6 Single-Crystal Phosphors: Enhanced Moisture Resistance and Performance in Warm White LEDs

“…7 This challenge can be effectively addressed by incorporating red-emitting material into wLEDs. 8,9 Substantial efforts have been devoted to exploring innovative rare-earthdoped red phosphors, 10−14 notably CaAlSiN 3 :Eu 2+ , which has been commercialized in recent years. 15,16 However, it exhibits several limitations including an excessively broad emission spectrum extending beyond 650 nm and diminishing luminous efficiency due to human eye insensitivity.…”