Photoluminescence of Eu2+ in SrGa2S4

A photoluminescence (PL) study of the green-emitting SrGa2S4:Eu2+ phosphor is reported. Diffuse reflectance, excitation, and emission spectra were examined with the aim to enlarge the fundamental knowledge about the emission of the Eu2+ ion in this lattice. The thermal dependence of the radiative properties was investigated. In particular, the Stokes shift, the crystal field splitting and the activation energy of the thermal quenching were determined. By combining these results with the information presented in literature, we discussed the location of the Eu2+ levels relative to the valence and conduction bands of SrGa2S4.