Influence of processing conditions on synthesis and photoluminescence of Eu3+-activated strontium stannate phosphors

The synthesis and photoluminescence (PL) properties of strontium stannate crystals doped with europium grown by mechanical activation in a high-energy vibro-mill have been investigated. The characteristics of Sr2SnO4:Eu3+ powders were found to depend on the heating conditions and the amounts of europium ions. The XRD profiles revealed that the system, (Sr1−xEux)2SnO4, could form stable solid solutions in the composition range x = 0-0.1. In the scanning electron microscopy (SEM) morphology observations, the shape of the grains was changed gradually from granular to globular as the calcination temperature increased from 1000 to 1300 °C. The calcined powders emit bright red luminescence centered at 619 nm due to the electric dipole transition 5D0 → 7F2, and the powders fired at 1200 °C were found to have the maximum PL intensity. The maximum PL intensity has been obtained for 5 mol% concentration of Eu3+ in Sr2SnO4.