Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2011; 59(5(1)): 3235-3238

Published online November 15, 2011

Copyright © The Korean Physical Society.

Application of MIR-FEL Irradiation to Selectively Excite Phonons in Wide-gap Semiconductors

Kyohei Yoshida, Taro Sonobe, M. A. Bakr, Y. W. Choi, Ryota Kinjo, M. Omer, Masato Takasaki, Satoshi Ueda, Naoki Kimura, Keiichi Ishida, Kai Masuda, Toshiteru Kii, Hideaki Ohgaki


A mid-infrared free electron laser (MIR-FEL) (5 - 20 ??m) facility (KU-FEL: Kyoto University Free Electron Laser) was constructed to aid in various energy science researchers at the Institute of Advanced Energy, Kyoto University. In May 2008, the first power saturation at 13.2 ??m was achieved. A pilot application to evaluate selective phonon excitation processes in solid materials by irradiating with MIR-FEL was implemented, and a preliminary experiment without FEL irradiation was conducted. N-doped silicon carbide (SiC) was selected as a sample material due to its unique electrical property where the lattice vibration and electronic structure are coupled. Two peaks at 1.8 - 2.4 eV and 2.4 - 2.8 eV, which showed strong temperature dependences in both their intensities and peak energy, were observed. These tendencies could be explained by a donor-acceptor pair luminescence (DAP) model with impurity and defects in the SiC sample. The results imply that we can verify the selective phonon excitation by investigating the change of PL spectrum introduced by MIR-FEL irradiation.

Keywords: Sillicon Carbide, Photoluminescenc, Free Electron Laser

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