Photoluminescence mechanisms of color-tunable Sr2CeO4: Eu3+, Dy3+ phosphors based on experimental and first-principles investigation

Abstract

We report single-phased color-tunable phosphors (Sr2CeO4: Eu3+, Dy3+) synthesized by a polymer-network gel method for UV–LED. The photoluminescence properties and possible energy transfer mechanisms of Eu3+ and Dy3+ in Sr2CeO4 were investigated by experiments and first principles calculations. The results show that the 5D0→7F2 emission of Eu3+ is enhanced by the increase in the amount of Eu3+ ions and Eu3+ substitution makes more stable defect than Dy3+ substitution does. The photoluminescence mechanism of Sr1.994−xEuxDy0.006CeO4 can be explained by the energy transfer model with the consideration of the defect conditions in the crystals.