Efficient near-infrared broadband garnet phosphor for pc-LED and its application to vascular visualization and night vision

Abstract

Ultra-broadband near-infrared (NIR) spectroscopy has unparalleled application prospects in intelligent detection and phosphor-converted light-emitting diodes (pc-LED), which are most likely to become the next generation of NIR light sources, has become a hot spot for research nowadays. To cope with the demand for more NIR spectroscopy applications, more efficient NIR phosphors need to be developed. Here, by screening the subject with a smaller band gap and by screening the suitable ion electronegativity of the lattice position where the Cr3+ is located, and then through the energy transfer, a series of Gd3Zn2GaGe2O12:xCr3+, yYb3+ (GZGG:Cr3+/Yb3+) NIR broadband garnet phosphors were found for the first time. By controlling the energy transfer process, the internal quantum yield (IQY) (54.9%), external quantum yield (EQY) (24.65%), bandwidth (260 nm), and thermal stability (60% at 150 °C) of NIR emission were substantially improved. The obtained phosphors are packaged with blue light chips into pc-LED, which can be applied in different fields such as vascular visualization and night vision.