Crystal structure, luminescence, and thermal stability of CsAlSi2O6:Tb3+ phosphors with highly efficient green emission

Green-emitting Tb3+-doped pollucite (Cs1-3xTbx)AlSi2O6 (x = 0.01–0.13) phosphors were synthesized by the high-temperature solid-state reaction method. Structural characterization of the prepared (Cs1-3xTbx)AlSi2O6 phosphors was performed using powder X-ray diffraction and X-ray photoelectron spectroscopy. The excitation and emission spectra showed green emission at ~543 nm because of the 5D4→7F5 transition under excitation at 238 nm. The optimum doping concentration of the Tb3+ ions was x = 0.07, and the quantum efficiency was 83.6%. The temperature dependence of emission spectra for x = 0.07 revealed that 92.7% and 78.4% of the initial value of the emission intensity at 300 K are retained at 400 K and 500 K, respectively. These results show that the green-emitting phosphors synthesized herein have good performance and potential applications in ultraviolet-C excited white light-emitting diodes.