Rare-earth-free Te4+ doped Y3Al5O12 blue-emission nanophosphors

Te doped Y3Al5O12 blue-emission nanophosphors were successfully fabricated by the sol-gel method. The effects of Te doping on the structure, morphology, valence state and luminescence properties of samples were investigated using XRD, SEM, XPS and PL techniques. The results demonstrate that all diffraction peaks are in line with pure Y3Al5O12 phase. SEM images exhibit that the prepared samples possess a uniform grain size and nearly spherical shape. The YAG:2 %Te4+ powder sintered at 900 °C shows intense blue emission at 467 nm under 280 nm excitation, with a lifetime of 2.36 μs. These findings suggest that YAG:Te4+ powders hold significant potential as suitable candidates for NUV-LED applications. For the development of inorganic fluorescent materials, it is necessary to explore fluorescent materials doped with non-rare-earth ions. As the ns2 type luminescence center, the luminescence of Te4+ is rarely studied. In this article, the Te4+-doped YAG nanophosphor is prepared for the first time by the sol-gel method. Its microstructure, particle morphology, and element valence have been studied in detail. More importantly, the fluorescence properties of Te4+-doped YAG nanophosphor have been studied. Under 280 nm UV excitation, it exhibits a broad blue emission band with a peak at 467 nm and a fluorescence lifetime of microseconds. The thermal stability of its luminescence was further studied, and its luminous quantum efficiency, color purity and other parameters were obtained. These works have very important value for the application of Te4+-doped YAG nano-fluorescent materials. Fig. 1. (a) Emission and excitation spectra of YAG:3 %Te4+ with various sintering temperatures. (b) The CIE diagram of YAG:xTe4+ powders excited by 280 nm. [Display omitted]