| AVS 60th International Symposium and Exhibition | |
| Surface Science | Thursday Sessions |
| Session SS+EN-ThM |
| Session: | Photocatalysis and Photochemistry at Surfaces |
| Presenter: | S. Yamamoto, The University of Tokyo, Japan |
| Authors: | S. Yamamoto, The University of Tokyo, Japan R. Yukawa, The University of Tokyo, Japan M. Emori, Sophia University, Japan K. Ozawa, Tokyo Institute of Technology, Japan M. Ogawa, The University of Tokyo, Japan K. Fujikawa, The University of Tokyo, Japan Sh. Yamamoto, The University of Tokyo, Japan R. Hobara, The University of Tokyo, Japan I. Matsuda, The University of Tokyo, Japan |
| Correspondent: | Click to Email |
Photocatalytic reactions on semiconductor oxide surfaces can be divided into four processes: (i) photon absorption, (ii) electron-hole pair formation, (iii) transport of photo-excited carriers from bulk to surface, and (iv) surface redox reactions. It is important to understand the dynamics of photo-excited carriers in order to make more efficient photocatalysts. Despite of its importance, little is known about transient electronic structures of photo-excited semiconductor surfaces.
Photoelectron spectroscopy (PES) has been successful in providing direct access to electronic structures of materials with surface sensitivity. The extension of PES to time-domain, or time-resolved PES, is now realized by the use of brilliant short pulse (several tens ps) x-ray available at the state-of-the-art synchrotron radiation facilities [1]. This allows us to study transient electronic structures of materials.
In this talk we will introduce the newly developed time-resolved PES system at the high-brilliance soft x-ray beamline BL07LSU at SPring-8 [2]. In the time-resolved PES measurements, the transient electronic structures after optical excitation by fs-laser pump pulses are monitored by ps soft x-ray probe pulses. The time-resolved PES studies on the relaxation of surface photovoltage effect on oxide surfaces such as SrTiO3(001) and ZnO(0001) will be presented.
References
[1] S. Yamamoto, I. Matsuda, J. Phys. Soc. Jpn., 82, 021003 (2013).
[2] M. Ogawa, S. Yamamoto, Y. Kousa, F. Nakamura, R. Yukawa, A. Fukushima, A. Harasawa, H. Kondoh, Y. Tanaka, A. Kakizaki, I. Matsuda, Rev. Sci. Instrum., 83, 023109 (2012).