Effects of synthesis temperature on the microstructures and photoluminescent properties of Eu₂O₃-doped Sr_2−xBa_xSiO₄ phosphors

In this study, Sr_2−xBa_xSiO₄ (x = 0, 0.2, and 0.4) was used as the host material and Eu₂O₃ was used as the activator to produce commercial Sr₂SiO₄:Eu, Sr_1.8Ba_0.2SiO₄:Eu, and Sr_1.6Ba_0.4SiO₄:Eu phosphors by a solid-state reaction method. All the Sr_2−xBa_xSiO₄–Eu phosphors were synthesized in the temperature range of 1000–1300 °C for 2 h. XRD patterns revealed that when different BaO contents and synthesis temperatures were used, all the Sr_2−xBa_xSiO₄–Eu phosphors had similarly crystalline properties. The mainly crystalline phase changed from the (121) to the (103) plane as the BaO content changed from 0 to 0.2. In the case of all Sr_2−xBa_xSiO₄–Eu powders, secondary or unknown phases were not observed if the synthesis temperature was lower than 1000 °C, and only the precursor SiO₂ phase was observed in the 1000 °C-synthesized Sr₂SiO₄–Eu powder. This study also thoroughly investigated the effects of different BaO contents and synthesis temperatures on the photoluminescent properties of Sr_2−xBa_xSiO₄–Eu phosphors. We show that the photoluminescent properties of Sr_2−xBa_xSiO₄–Eu phosphors are dependent on the BaO content and synthesis temperature.