Effect of Al3+ Additions on the Microstructure and Photoluminescence of SrTiO3:Pr3+ Phosphors Produced by the Sol–Gel Method

The effect of various concentrations of Pr3+ on the structural and luminescent characteristics of SrTiO3:Pr3+ phosphors synthesized by the sol–gel method was investigated. Maximum intensity of red luminescence (617 nm) for SrTiO3:Pr3+ with excitation by ultraviolet radiation is observed at an effective Pr3+ concentration of 0.2 mole %. It was shown that the addition of aluminum at the optimum Pr3+ concentration leads to deterioration of the crystallinity and reduces brightness of the SrTiO3:Pr3+ luminescence. The reason for the last effect may be the presence of minute amounts of iron impurity in the initial reagents.