Red luminescence properties of Te4+-doped CaYAlO4 phosphors

Abstract Novel Te4+-doped CaYAlO4 phosphors were obtained by a solid-state reaction. Te4+-doped CaYAlO4 samples had a tetragonal crystal structure and emit deep-red light at 715 nm excited by 325 nm, which was ascribed to Te4+ luminescence center. The luminescent intensity of CaYAlO4: Te4+ samples increased with the sintering temperature increasing, reaching a maximum at 1500 °C, then began to drop. The optimal Te4+ doping concentration was 2 mol%. Lifetime of CaYAlO4: 2%Te4+ phosphors was 1.54 ms. The luminescent intensity of CaYAlO4: 2%Te4+ phosphors decreased with the increase of test temperature and reached to 35.0% of the initial value at 425 K. The CaYAlO4: Te4+ phosphors have potential applications in bio-imaging, temperature sensor, solid-state lighting and solar cells etc.