Efficient and ultra-broadband near-infrared emission in perovskite-like Mg4Sb2O9:Cr3+ phosphor

Near-infrared (NIR) spectroscopy based on phosphor-converted NIR light-emitting-diode (LED) has extensive applications in modern life, stimulating the exploration of ultra-broadband NIR phosphors with high efficiency. Herein, Cr3+-doped perovskite-like Mg4Sb2O9 phosphor was synthesized, which exhibits a NIR emission with peak wavelength of 855 nm, and a full width at half maximum (FWHM) of about 207 nm. Upon 442 nm excitation, the quantum efficiency (QY) and absorption efficiency (AE) were determined to be 59.1 % and 48.3 %, respectively; while the luminescence intensity remained 61.5 % of room temperature at 373 K, indicating an excellent efficient and a moderate thermal stability of this material. The fabricated NIR pc-LED through combining the optimized phosphor with a 455 nm LED chip presents an output power of 20.1 mW and a photoelectronic conversion efficiency of 3.6 % under a driving current of 175 mA. These results suggest that Mg4Sb2O9:Cr3+ phosphor with excellent luminescent performance may have good potential for applications in NIR pc-LEDs.