Luminescence properties and energy transfer of broadband NIR phosphor LiMgZrO: 1.0%Cr, y%Yb.

The discovery of high thermal stability, broad-band near-infrared (NIR) fluorescent phosphors holds significant potential in applications such as non-destructive testing, promoting plant growth, and night vision devices. In this study, a novel broad-band NIR phosphors LiMgZrO (LMZ): 1.0 %Cr, y%Yb were synthesized via a high-temperature solid-state reaction method, with the optimal doping concentration found to be y = 1.5. These phosphors exhibited broad NIR emission in the range of 700-1050 nm by effective energy transfer from Cr to Yb. The maximum full width at half maximum (FWHM) of the Cr/Yb co-doped LMZ phosphor is 270 nm. The thermal stability of the phosphors was improved with Yb co-doping. Additionally, energy transfer from Cr to Yb was confirmed through luminescence spectra and lifetime analysis. Finally, NIR pc-LED devices composed of a 460 nm ultraviolet chip and LMZ: 1.0 %Cr, 1.5 %Yb phosphors were fabricated, offering a highly promising source of invisible light. These results demonstrate the wide-ranging potential applications of this novel, high thermal stability, and ultra-broad NIR emitting fluorescent phosphor.