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

Abstract

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 Y2Mg2Ga2-xSi2O12: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.