Luminescence properties of Cr3+-doped Al6Ge2O13 broadband near-infrared phosphor

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are gaining attention as new solid-state light sources for food safety and health monitoring. Herein, a series of Cr3+-doped Al6Ge2O13 (AGO) NIR phosphors were obtained by the high-temperature solid state reaction. The photoluminescence (PL) excitation spectrum of AGO:Cr3+ shows a strong broadband absorption in the 400–500 nm region, which corresponds well to the blue light chip. The phosphor's PL emission spectrum exhibits a broadband spanning 600–1000 nm. The integrated emission intensity of AGO:3%Cr3+ at 420 K can keep 81% of that at 300 K, demonstrating good luminous thermal stability. The near-infrared output power of pc-LED device integrating AGO:Cr3+ phosphor with a 430 nm blue light chip reaches 81.7 mW at 300 mA. The device's electroluminescence spectrum displays a broadband centered at 780 nm, with a full width at half maximum (FWHM) of 160 nm. These findings could drive the development of NIR pc-LED light sources for miniaturized near-infrared spectrometers.