@article{oai:uec.repo.nii.ac.jp:00009052,
 author = {Nanai, Yasushi and Suzuki, Yousuke and Okuno, Tsuyoshi},
 issue = {10},
 journal = {Journal of Physics D: Applied Physics},
 month = {Mar},
 note = {Lanthanide (Ln)-doped yttrium thiosilicate (Y1−x Ln x )4(SiS4)3 is synthesized, and its optical properties are studied. In (Y1−x Tb x )4(SiS4)3, the green photoluminescence band corresponding to the intra 4f transition of 5D4  →  7F5 appears at 545 nm and becomes the maximum for x  =  0.2 in the range x  =  0.01 to 1. The internal quantum efficiency is higher (11% for x  =  0.01) for the thiosilicate host excitation (360 nm) than for the direct excitation (1.6%) of the intra 4f transition of 5D4  ←  7F6 (489 nm). A time-resolved photoluminescence study shows that the luminescence of defect states of thiosilicate hosts decays faster (typically 10–30 ns) for higher Tb3+ concentration x. In addition, the rise time of Tb3+ photoluminescence is shorter (10–40 ns) for greater x. Energy transfer from the thiosilicate host to Tb3+ is discussed using these results. For all of (Y1−x Ln x )4(SiS4)3 (x  =  0.01, Ln  =  Pr, Nd, Dy, Er or Tm), the internal quantum efficiency is higher for the host excitation (11–21%) than for the direct excitation of intra 4f transitions (1.1–12%). A photoluminescence excitation study reveals broad host absorption in 300–400 nm for Ln luminescence. These results show the promising characteristics of the host absorption of (Y1−x Ln x )4(SiS4)3 phosphors and their optical properties.},
 title = {Efficient host excitation in thiosilicate phosphors of lanthanide(III)-doped Y4(SiS4)3},
 volume = {49},
 year = {2016}
}