Abstract
• The Sr 3- x Ca x La(VO 4 ) 3 : Sm 3+ and Sr 2 CaLa(VO 4 ) 3 : y Sm 3+ were synthesized by citric-assisted sol-combustion method. • SCLVO: Sm 3+ has a hexagonal structure with space group R-3 m (166). • The replacement of Sr 2+ by Ca 2+ improves the emission intensity of Sr 3 La(VO 4 ) 3 : Sm 3+ phosphor. • Phase structure, luminescent behaviors and thermal stability were systematically studied. Sr 3- x Ca x La(VO 4 ) 3 : Sm 3+ ( x = 0, 0.5, 1.0, 1.5, 2.0, 2.5) and novel Sr 2 CaLa(VO 4 ) 3 : y Sm 3+ (SCLVO: y Sm 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 Sr 3- x Ca x La(VO 4 ) 3 : Sm 3+ phosphors were obtained when x < 2.5. The change in particle shape and unit cell parameters of the Sr 3- x Ca x La(VO 4 ) 3 : Sm 3+ 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 → 6 H 7/2 transition of Sm 3+ . 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).
Published Version
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