Thermally Stable CaLu 2 Mg 2 Si 3 O 12 :Cr 3+ Phosphors for NIR LEDs

Near‐infrared (NIR) phosphor‐converted (pc) light‐emitting diode (LED) is a promising next‐generation tiny light source for smart and broadband NIR spectroscopy technology. However, NIR phosphors suffer from challenges in terms of low efficiency and thermal stability. Herein, by selecting a host with large bandgap and weakening the coupling effect to Cr 3+ , the novel CaLu 2 Mg 2 Si 3 O 12 :Cr 3+ (CLMSG:Cr 3+ ) NIR phosphor is discovered that has an external quantum efficiency of 20.7% and high thermal stability (92.1%@100 °C). Under ≈450 nm excitation, CLMSG:Cr 3+ shows broad NIR emission from 650 to 900 nm with a band width of ≈120 nm. The fabricated tiny pcLED demonstrates bright NIR light (34.75 mW@100 mA) with photoelectric efficiency of 11.6%.