Crystal structure, luminescence properties and thermal stability of novel Sr2CaLa(VO4)(3): Sm3+ phosphor synthesized by the combustion method

Sr3-xCaxLa(VO4)(3): Sm3+ (x = 0, 0.5, 1.0, 1.5, 2.0, 2.5) and novel Sr2CaLa(VO4)(3): ySm(3+) (SCLVO: ySm(3+), y = 0.01, 0.03, 0.05, 0.07, 0.09) phosphors were synthesized by the citric acid-assisted sol-combustion method. The crystal structure, morphology, concentration-dependent emission spectrum, decay time, and thermal stability of phosphors were studied. These synthesized phosphors have a hexagonal structure with a space group of R-3 m (166). High-purity Sr3-xCaxLa(VO4)(3): Sm3+ phosphors were obtained when x < 2.5. The change in particle shape and unit cell parameters of the Sr3-xCaxLa(VO4)(3): Sm3+ phosphors led to reduced luminescence performance when the Ca-2(+) concentration was x > 1. The optimal doping concentration of Sm-3(+) in the SCLVO host is 3 mol%. Under the excitation of 402 nm near-ultraviolet (NUV) light, all phosphors in this series emit orange-red light at 603 nm, which is attributed to the (4)G(5)(/2)-> H-6(7)/2 transition of Sm3+. The SCLVO: 0.03Sm(3+) phosphor exhibits a double exponential decay time of 0.872 ms, excellent thermal stability with an activation energy E-a of 0.232 eV, a chromaticity coordinate of (0.5817, 0.4136), and a high color purity of 98.48%. These experimental results demonstrate the potential application of phosphor SCLVO: 0.03Sm(3+) in the red component of white light-emitting diodes (WLEDs). (C) 2021 Elsevier B.V. All rights reserved.