Near-infrared downconversion luminescence of SrMoO 4 :Tm 3+ ,Yb 3+ phosphors

Abstract Tm 3+ and Yb 3+ codoped SrMoO 4 phosphors were synthesized by the high-temperature solid-state reaction method. The structure, ultraviolet-visible diffuse reflectance spectra, photoluminescence, decay properties and theoretical energy transfer efficiency of the phosphors were investigated in detail. The electronic structure and band gap of SrMoO 4 were estimated by density functional theory (DFT) calculation. The XRD results show that all the prepared phosphors can be readily indexed to scheelite-type structure. The strong visible emission around 473 nm from Tm 3+ ( 1 G 4 → 3 H 6 ) and near-infrared (NIR) emission around 998 nm from Yb 3+ ( 2 F 5/2 → 2 F 7/2 ) of the SrMoO 4 :Tm 3+ ,Yb 3+ phosphors were observed under 283 nm excitation. The dependence of the visible and NIR emissions on Yb 3+ concentration have also been investigated. The quenching concentration of Yb 3+ ions approaches 10 mol%. In addition, the energy transfer processes and possible transfer routes were proposed.