@article{530c7c8357224bd6a9cde5c51aa20aa3,
title = "Visualizing hidden electron trap levels in Gd3Al2Ga3O12:Ce crystals using a mid-infrared free-electron laser",
abstract = "The energy levels of electron traps (namely, defect complexes associated with oxygen vacancies) in Gd3Al2Ga3O12:Ce (GAGG:Ce) were studied at 12 K using mid-infrared (MIR) light pulses from a free-electron laser (FEL) as the probe light. Ce3+ 5d-4f luminescence was stimulated by the MIR light pulse following an ultraviolet light pulse. Stimulation of Ce3+ 5d-4f luminescence by MIR light pulses was pronounced above 0.31 eV. This result is consistent with that of previous work based on a trap-mediated luminescence model. It is concluded that the electron trap levels are located 0.31 eV below the bottom of the conduction band. This study demonstrates that MIR-FEL is applicable for the determination of hidden electron trap levels.",
author = "Mamoru Kitaura and Heishun Zen and Kei Kamada and Shunsuke Kurosawa and Shinta Watanabe and Akimasa Ohnishi and Kazuhiko Hara",
note = "Funding Information: This study was supported through KAKENHI (Grant No. 26420673) from the Japan Society for the Promotion of Science (JSPS), Joint Research Program on Zero-Emission Energy Research, Institute of Advanced Energy, Kyoto University, the Inter-University Cooperative Research Program of the Institute for Materials Research, Tohoku University, and Cooperative Research Project of the Research Institute of Electronics, Shizuoka University. M.K. acknowledges financial support from Futaba Electronic Memorial Foundation.",
year = "2018",
month = jan,
day = "15",
doi = "10.1063/1.5008632",
language = "English",
volume = "112",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "3",
}