Glass-Crystallized Luminescence Translucent Ceramics toward High-Performance Broadband NIR LEDs

Abstract

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are newly emergent broadband light sources for miniaturizing optical systems like spectrometers. However, traditional converters with NIR phosphors encapsulated by organic resins suffer from low external quantum efficiency (EQE), strong thermal quenching as well as low thermal conductivity, thus limiting the device efficiency and output power. Through pressureless crystallization from the designed aluminosilicate glasses, here broadband Near-infrared (NIR) emitting translucent ceramics are developed with high EQE (59.5%) and excellent thermal stability (<10% intensity loss and negligible variation of emission profile at 150 °C) to serve as all-inorganic visible-to-NIR converters. A high-performance NIR phosphor-converted light emitting diodes is further demonstrated with a record NIR photoelectric efficiency (output power) of 21.2% (62.6 mW) at 100 mA and a luminescence saturation threshold up to 184 W cm−2. The results can substantially expand the applications of pc-LEDs, and may open up new opportunity to design efficient broadband emitting materials.