Photoluminescence and Crystal-Field Analysis of Pr3+-Doped SrMoO4 Phosphors

Abstract

Abstract The phosphor SrMoO4:Pr3+ was successfully prepared by high-temperature solid-state reaction process, and characterised by X-ray diffraction (XRD), scanning electron microscope (SEM), and fluorescence spectrometer. The results show that the prepared SrMoO4:Pr3+ has a scheelite structure with pure phase and represents leaf-like shapes with good dispersity. The strong electron absorbabilities are located at 220–300 nm (charge transfer band), 448, 474, and 487 nm, respectively. The emission spectrum of the SrMoO4:Pr3+ phosphor was characterised, which peaked at 529, 545, 554, 600, 619, and 645 nm, corresponding to the f–f transitions of Pr3+. The average International Commission on Illumination (CIE) chromaticity coordinates of the phosphors are x≈0.455, and y≈0.520, and the optimum doping mole fraction of Pr3+ is 0.2 mol.%. To better understand the fluorescent behavior of as-prepared phosphors, a complete 91×91 energy matrix was built by an effective Hamiltonian operator, including free ion and crystal-field interactions. The fluorescent spectra of Pr3+ ion at the tetragonal (S 4) Sr2+ site of SrMoO4 crystal were firstly calculated from a full diagonalisation (of energy matrix) method. The fitting values are in good agreement with the experimental data.