Effects of the Concentration of Eu3+ Ions and Synthesizing Temperature on the Luminescence Properties of Sr2−xEuxZnMoO6 Phosphors

The effect of Eu2O3 concentration on the luminescence properties of double perovskite (cubic) Sr2−xEuxZnMoO6 phosphors was thoroughly investigated using different synthesizing temperatures. Phosphors with the composition Sr2−xEuxZnMoO6, where Eu2O3 was substituted for SrO and x was changed from 0 to 0.12, were synthesized by the solid-state method at temperatures of 900–1200 °C, respectively. Analysis of the X-ray diffraction (XRD) patterns showed that even when the synthesizing temperature was 1100 °C, secondary or unknown phases were observed in Sr2−xEuxZnMoO6 ceramic powders. The effect of the concentration of Eu3+ ions on the luminescence properties of the Sr2−xEuxZnMoO6 phosphors was readily observable because no characteristic emission peak was observed in the Sr2ZnMoO6 phosphor. Two characteristic emission peaks at 597 and 616 nm were observed, which correspond to the 5D0–7F1 and 5D0–7F2 transitions of Eu3+ ions, respectively. The two characteristic emission peaks of the Sr2−xEuxZnMoO6 phosphors were apparently influenced by the synthesizing temperature and the concentration of Eu3+ ions. When x was larger than 0.08, a concentration quenching effect of Eu3+ ions in the Sr2−xEuxZnMoO6 phosphors could be observed. The lifetime of the Sr2−xEuxZnMoO6 phosphors decreased as the synthesizing temperature increased. A linear relation between temperature and lifetime was obtained by using a fitting curve of t = −0.0016 × T + 3.543, where t was lifetime and T was synthesizing temperature