Mg2+ modified LiBaF3: Ni2+ perovskite single crystals with broadband long wavelength near-infrared emission for imaging human vascular structures

Near-infrared (NIR) luminescence materials are ideal candidates for applications in three-dimensional biomedical imaging and night vision. Here, we constructed an ultra-broadband NIR material based on LiBaF3: Ni2+ single crystals with NIR emission at 1400 nm and a full width at half maxima (FWHM) of 254 nm from 1100 to 1700 nm wavelength, covering the regions of NIR-II and NIR-III. Through the activation of inactive Mg2+, the NIR emission could be improved by a factor of two, and the FWHM enhanced to 273 nm. That is ascribed to the lattice distortion by the addition of Mg2+ as well as the charge asymmetry between the Mg2+ and Li+ ions. The prepared Ni2+/Mg2+ doped NIR perovskite single crystals were packaged with a commercial high-efficiency near-ultraviolet LED chip (@395 nm) to construct NIR single crystal LEDs, and their promising applications with high efficiency were demonstrated by NIR night-vision monitoring and vein non-destructive imaging.