Improving and broadening luminescence in Gd2−xAlxGaSbO7:Cr3+ phosphors for NIR LED applications

Abstract

Near-infrared (NIR) spectroscopy has garnered substantial attention owing to its diverse merits and widespread applications. Meanwhile developing phosphors with broadband and efficient NIR emission is still an enormous challenge for constructing NIR light sources. Herein, enhanced and broadened NIR luminescence of Gd_2−xAl_xGaSbO₇ (G_2−xA_xGSO):y%Cr³⁺ phosphors can be realized via modifying the crystal field environment of Cr³⁺ induced by Al³⁺ → Gd³⁺ cation substitution. Upon blue light irradiation, G_1.4A_0.6GSO:4%Cr³⁺ exhibits a broadband luminescence ranging from 650 to 1000 nm with a full width at half maximum (FWHM) of 136 nm, excellent thermal stability, and a tiny chromaticity shift. Through incorporating the resulting powders into a blue light-emitting diode (LED) chip, a NIR phosphor-converted (pc) LED with a high output power of 62.99 mW and a photoelectric conversion efficiency of 13.38% was manufactured. The fabricated pc-LED shows application potential in nondestructive food analysis. These findings confirm that the as-synthesized G_2−xA_xGSO:Cr³⁺ phosphor is a promising candidate for application in NIR pc-LEDs.