2021 Volume 129 Issue 4 Pages 223-225
In this study, phosphors based on Srx(La9.2−xTb0.8)(SiO4)6Oα (x = 2, 3, 4, 5, and 6) ceramic powders were prepared and their photoluminescence (PL) spectra were investigated. The phosphors show green emission at approximately 545 nm when excited by 378 nm UV light. X-ray photoelectron spectroscopy suggests that Tb in the Tb3+ and Tb4+ valence states coexist in phosphors at a Tb3+/Tb4+ atomic ratio of unity. [Sr2−x(La,Tb)x]SiOα was confirmed to exist in addition to Srx(La9.2−xTb0.8)(SiO4)6Oα at x = 4, 5, and 6. The PL intensity increased with increasing Sr(x) content, which is considered to be due increasing Srx(La9.2−xTb0.8)(SiO4)6Oα particle size. The strongest PL intensity was observed at x = 6, where the absorptivity, internal quantum efficiency, and external quantum efficiency were 20, 50, and 10 %, respectively.