Photoluminescence in MgxSr1−xAl2O4:Eu2+, Nd3+and electron–vibrational interaction in the Eu2+ 5d states

Green phosphor compositions MgxSr1−xAl2O4:Eu, Nd (with x=0.05–0.25) were prepared by solid state reaction method. The effect of Mg substitution on photoluminescence characteristics was investigated. The photoluminescence show intense green emission for MgSrAl2O4:Eu2+, Nd3+ with long persistence. This green emission corresponds to transitions from 4f65d1 to 4f7 of Eu2+ ion. Comparative analysis of the excitation and emission spectra were used to evaluate the crystal field splitting of the 5d states of Eu2+ and the parameters of electron–vibrational interaction, such as Huang–Rhys factor, effective phonon energy, and zero-phonon line position.