Synthesis and photoluminescence properties of NUV-excited NaBi(MoO4)2: Sm3+ phosphors for white light emitting diodes

Abstract In this work, a group of NaBi(MoO4)2 phosphors doped with various Sm3+ concentrations were prepared utilizing the solid state reaction. The crystalline phases were identified by the implement of XRD as well as Rietveld refinement, and the relevant data of the optimum sample turn out to be a = b = 5.245 A, c = 11.563 A, Rp = 7.66%, Rwp = 9.64% and χ2 = 1.512. Upon the irradiation of 406 nm, all the phosphors exhibited orange-red light emission with the primary peak at 599 nm. Furthermore, the optimal doping concentration of Sm3+ ion was determined as 0.08 mol, and the mechanism of energy transfer between two adjacent Sm3+ ions was dominated by the dipole-dipole interaction. The possible lattice sites occupied by Sm3+ ions were investigated via the fitting function type of decay curves. The calculated CIE chromaticity coordinate of NaBi(MoO4)2: 0.08Sm3+ phosphor verified that its emission light was located in the orange-red region. The aforementioned results demonstrated that the NaBi(MoO4)2: Sm3+ phosphors could be used in the area of NUV-excited white light emitting diodes.