Broadening and enhancing emission of Cr3+ simultaneously by co-doping Yb3+ in Ga1.4In0.6SnO5

Abstract

Cr3+ doped broadband near-infrared (NIR) emitting phosphors are currently the focus of research. Researchers have developed a variety of strategies to achieve broad and strong NIR emission. However, it is a conundrum to simultaneously broaden and enhance the emission of Cr3+ with a single strategy. In this work, we solved this problem by co-doping Yb3+. Under 452 nm excitation, Ga1.4In0.6SnO5 (GISO):0.01Cr3+ shows ultrabroadband NIR emission covering 650–1300 nm with a peak of 884 nm. The full width half maximum (FWHM) of the emission is 215 nm and the internal quantum yield (IQY) is 25%. This indicates that the double sites occupation strategy is favorable to achieve ultra-broadband NIR emission. The co-doping of Yb3+ can effectively broaden and enhance the emission of Cr3+. The FWHM for GISO:0.01Cr3+,0.002Yb3+ extends to 245 nm, and the IQY increases to 28%. Further increasing the concentration of Yb3+ to 0.005, the IQY is lifted to 32%. Finally, a phosphor-converted light emitting diode (pc-LED) was prepared by integrating the GISO:0.01Cr3+,0.002Yb3+ with a blue light chip. Under the current drive of 40 mA, the maximum output power of pc-LED is 4.54 mW, and the photoelectric conversion efficiency is 4.12%. These results indicate that Yb3+ ions can simultaneously broaden the emission band and improve the emission efficiency. This work provides an effective strategy for the design of efficient broadband NIR phosphors in the future.