Efficient broadband NIR garnet phosphor Ca2LuScGa2Si2O12:Cr3+,Yb3+ for NIR pc-LED applications

Abstract

Near-infrared phosphor-converted light emitting diodes (NIR pc-LEDs) have broad application prospects in the fields of solar cells, spectroscopic analysis, fluorescent labeling and biomedical testing. The current research faces challenges in enhancing the thermal stability and efficiency of near-infrared (NIR) emitting phosphors. Herein, a broadband NIR phosphor Ca2LuScGa2Si2O12:Cr3+ (CLSGS:Cr3+) was successfully synthesized. CLSGS:Cr3+ phosphor displays a broadband emission in the range (650–900 nm) with a full width at half maximum (FWHM) of 150 nm, a good luminescent thermal stability (I373K/I298K = 73%), and a high internal quantum efficiency (IQE = 70.3%). Moreover, the introducing Yb3+ into CLSGS:Cr3+ significantly improves thermal stability (I373K/I298K = 93%) and enhances internal quantum efficiency (IQE = 90.5%). By combining CLSGS:Cr3+,Yb3+ with a 460 nm commercial LED chip, the fabricated NIR pc-LED devices demonstrates potential applicability in night vision and bio-imaging.