Broadband near-infrared emitting Cr3+-activated InGaO3(ZnO)4 phosphor and its application in pc-LEDs

In broadband near-infrared (NIR) phosphor converted to light-emitting diodes (pc-LEDs), Cr3+-activated phosphors have received a lot of attention. Herein, we developed a novel InGaO3(ZnO)4: xCr3+ (x = 0.001–0.02) with NIR broadband emission through a solid-state reaction at high temperature. Its excitation spectrum covers the blue light region, with the peak at 467 nm, which is suitable for blue light chip excitation. The optimum Cr3+ ion doping content is x = 0.01 and the emission spectrum ranges from 650 nm to 950 nm with a large full width at half maximum (FWHM) of 119 nm. Moreover, the internal quantum efficiency (IQE) of InGaO3(ZnO)4: 0.01Cr3+ phosphor is about 79%. Meanwhile, the phosphor exhibits good thermal stability due to the relatively weak electron-phonon coupling effect, and the emission intensity at 373 K can retain 57.7% of that at 303 K. The packaged pc-LED shows good NIR light penetration ability in spectral transmission tests, which indicates that the pc-LED has great application potential in portable devices as a light source.