Highly efficient broadband near-infrared luminescence phosphors Ca3MgSn0.5Zr0.5Ge3O12:Pr3+,Cr3+ for multifunctional applications in pc-LEDs field

Exploring high-performance broadband near-infrared (NIR) emitting materials is crucial for the development of NIR devices. In this study, Ca3MgSn0.5Zr0.5Ge3O12:Cr3+ and rare earth ion Pr3+ co-doped Ca3MgSn0.5Zr0.5Ge3O12:Pr3+,Cr3+ phosphors were successfully synthesized. By utilizing time-resolved emission spectroscopy (TRES), photoluminescence (PL) spectra, and fluorescence decay curve, the Ca3MgSn0.5Zr0.5Ge3O12:Cr3+ phosphor is determined to exhibit a broadband emission (650–1150 nm) with a peak at 795 nm due to Cr3+ occupying multiple cationic sites. Ca3MgSn0.5Zr0.5Ge3O12:0.1Cr3+ has excellent thermal stability (86%@425 K), and co-doping Pr3+ ions into Ca3MgSn0.5Zr0.5Ge3O12:0.1Cr3+ obtains highly efficient NIR emission. The Ca3MgSn0.5Zr0.5Ge3O12:0.01Pr3+,0.1Cr3+ phosphor has quantum yield of 89.4% thanks to the energy transfer effect from Pr3+ to Cr3+. The fabricated NIR phosphor-converted light emitting diodes (pc-LEDs) by integrating the blue chip with Ca3MgSn0.5Zr0.5Ge3O12:0.01Pr3+,0.1Cr3+ has diverse applications including night vision, non-destructive testing, and medical imaging.