Enhancement of green long lasting phosphorescence in CaSnO3:Tb3+ by addition of alkali ions

• Published in: Physica. B, Condensed matter Condensed matter, 2013-03, Vol.412, p.36-40
• Main Authors: Liang, Zuoqiu, Zhang, Jinsu, Sun, Jiashi, Li, Xiangping, Cheng, Lihong, Zhong, Haiyang, Fu, Shaobo, Tian, Yue, Chen, Baojiu
• Format: Article
• Language: English
• Subjects: Afterglow; Alkali ions; CaSnO3:Tb3; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other solid inorganic materials; Photoluminescence; Physics; Thermoluminescence
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2012.12.013

Long lasting phosphors of CaSnO3:Tb3+ added alkali ions (Li+, Na+, K+) were prepared by solid-state reaction. The phosphorescence of samples consists of a group of green emission lines originating from 5D4→7FJ transitions of Tb3+. The afterglow spectra and concentration quenching behaviors of fluorescence were investigated in the Tb3+ mono-doped sample. The result shows the optimal doping concentration of Tb3+ is 0.3mol%. In the co-doped samples, the doping concentrations of Tb3+ and alkali ions are both at 0.3mol%. It is found from the afterglow decay curves that the introduction of alkali ions can prolong the phosphorescent lasting time and the sample of incorporating Na+ shows the best result. Tb3+ and alkali ions can substitute Ca2+ ions, acting as hole and electron traps, respectively. The thermoluminescence (TL) spectra are also investigated. The depths of traps for the mono- and co-doped samples are calculated to be 0.622, 0.541, 0.529 and 0.538eV, respectively. Moreover, the possible mechanism of the green long lasting phosphorescence is proposed based on the experiment results.