Novel broadband NIR phosphors Y₂Mg₂Ga₂Si₂O₁₂:xCr³⁺ for NIR LED applications

The Cr³⁺-doped near-infrared (NIR) phosphors have been extensively investigated owing to their promising applications in biomedicine, food safety detection, and night vision surveillance. However, achieving broadband (FWHM > 160 nm) NIR emission is still challenging. In this paper, novel Y₂Mg₂Ga_2-Si₂O₁₂:xCr³⁺ (YMGS:xCr³⁺, x = 0.005-0.08) phosphors were prepared by a high-temperature solid-state reaction. The crystal structure, photoluminescence properties of the phosphor, and the device performance of a pc-LED were researched in detail. When excited at 440 nm, the YMGS:0.04Cr³⁺ phosphor exhibited broadband emission in the range of 650-1000 nm, peaking at 790 nm with a full width at half-maximum (FWHM) of up to 180 nm. The wide FWHM of YMGS:Cr³⁺ is conducive to its extensive application in NIR spectroscopic technology. In addition, the YMGS:0.04Cr³⁺ phosphor could maintain 70% of the initial emission intensity at 373 K. By combining the commercial blue chip with the YMGS:0.04Cr³⁺ phosphor, the resulting NIR pc-LED demonstrated a near-infrared output power of 14 mW with a photoelectric conversion efficiency of 5% at a drive current of 100 mA. This work provides a broadband emission NIR phosphor option for NIR pc-LED devices.