TY - JOUR
T1 - Judd-Ofelt analysis and emission quantum efficiency of Tb-fluoride single crystals
T2 - LiTbF4 and Tb0.81Ca0.19F 2.81
AU - Vasyliev, V.
AU - Víllora, E. G.
AU - Sugahara, Y.
AU - Shimamura, K.
N1 - Funding Information:
This work has been partially supported by the Ministry of Education, Science, Sport and Culture, Grant-in-Aid for Scientific Research (C), 22560316, 2010.
PY - 2013/5/28
Y1 - 2013/5/28
N2 - Terbium is the key element for highly efficient green phosphors and visible-near IR Faraday isolators. We have recently shown the potential of LiTbF4 and Tb0.81Ca0.19F2.81 as visible Faraday rotators. In this work, we present a detail spectroscopic analysis of Tb3+ (4f8) in these two compounds with different crystal structures. By means of the Judd-Ofelt theory, the emission branching ratios and lifetimes of the Tb3+ excited states have been estimated. These results are compared with experimental values obtained for the emitting 5D4 level, as well as with the absolute light yield measurements. Tb3+ in LiTbF4 exhibits a high quantum efficiency, and its radiative lifetime is confirmed to be 7 ms. Instead, the ionic conductor Tb0.81Ca0.19F2.81, which presents a high concentration of vacant sites, shows a lower quantum efficiency and a radiative lifetime about three times larger than estimated. Absorption and emission spectra of Tb0.81Ca0.19F2.81 are broad, so that any fine structure of energy levels can be resolved. In contrast, a detailed study of the splitting of Tb3+ multiplets in Stark energy levels is carried out for LiTbF4.
AB - Terbium is the key element for highly efficient green phosphors and visible-near IR Faraday isolators. We have recently shown the potential of LiTbF4 and Tb0.81Ca0.19F2.81 as visible Faraday rotators. In this work, we present a detail spectroscopic analysis of Tb3+ (4f8) in these two compounds with different crystal structures. By means of the Judd-Ofelt theory, the emission branching ratios and lifetimes of the Tb3+ excited states have been estimated. These results are compared with experimental values obtained for the emitting 5D4 level, as well as with the absolute light yield measurements. Tb3+ in LiTbF4 exhibits a high quantum efficiency, and its radiative lifetime is confirmed to be 7 ms. Instead, the ionic conductor Tb0.81Ca0.19F2.81, which presents a high concentration of vacant sites, shows a lower quantum efficiency and a radiative lifetime about three times larger than estimated. Absorption and emission spectra of Tb0.81Ca0.19F2.81 are broad, so that any fine structure of energy levels can be resolved. In contrast, a detailed study of the splitting of Tb3+ multiplets in Stark energy levels is carried out for LiTbF4.
UR - http://www.scopus.com/inward/record.url?scp=84879125593&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84879125593&partnerID=8YFLogxK
U2 - 10.1063/1.4807649
DO - 10.1063/1.4807649
M3 - Article
AN - SCOPUS:84879125593
SN - 0021-8979
VL - 113
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 20
M1 - 203508
ER -