Crystal Structure and Luminescence Properties of Dy3+-Doped Double-Perovskite Tellurites

White-emitting SrSc 1- x LiTeO 6 : x Dy 3+ phosphors were conveniently synthesized by a conventional high-temperature solid-state synthesis process. The crystal structure, photoluminescence spectrum characteristics, fluorescence quenching phenomenon, fluorescence lifetime analysis and the thermal stability of SrSc 1- x LiTeO 6 : x Dy 3+ phosphors were comprehensively illustrated. The E gap of the SrScLiTeO 6 host was approximately 4.65 eV based on diffuse reflectance spectroscopy (DRS) analysis. Moreover, the SrSc 0.94 LiTeO 6 :0.06Dy 3+ phosphor exhibits two principal emission bands: the narrow-band emission at 481 nm ( 4 F 9/2 → 6 H 15/2 , magnetic dipole transition, blue light area) and 573 nm ( 4 F 9/2 → 6 H 13/2 , electric dipole transition, yellow light area) under the excitation of 366 nm ultraviolet light, respectively. The values of τ are determined to be 0.558, 0.380, 0.307 and 0.254 ms for SrSc 1- x LiTeO 6 : x Dy 3+ ( x = 0.005, 0.01, 0.04, 0.08) samples, respectively. The value of Δ E for SrSc 0.94 LiTeO 6 :0.06Dy 3+ phosphor is deduced to be 0.1969 eV, which indicates excellent thermal stability. In addition, the CIE coordinates are located in the white light-emitting area. The abovementioned results show that the SrSc 1- x LiTeO 6 : x Dy 3+ can serve as a phosphor with potential application value for outdoor illumination.