Formation of transient pairs of F and H centers at next nearest neighbor sites in alkali chloride crystals studied by the time delayed double excitation spectroscopy in picosecond range |
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| Authors: | Yoshiro Suzuki Abe Hidetoshi Tasaki Kouji Hirat Masamitsu |
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| Affiliation: | Department of Applied Physics , Faculty of Engineering, Tohoku University , Sendai, 980, JAPAN |
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| Abstract: | Abstract By making use of the time delayed double excitation spectroscopy, transient absorption spectra just after the excitation of self-trapped excitons (STE) from the lowest triplet state to higher excited states have been observed to find the transient F-H center pair [F-H]. Absorption bands due to transient [F-H] appeared as a doublet peaking at 2.70eV and 2.86eV (NaCl), at 2.25eV and 2.38eV (KCl) and at 1.97eV and 2.09eV (RbCl) at 108ps after the excitation. The ratio of peak heights between bands at low and high energy sides was 2:1 in all crystals. The results were tentatively understood by a recent theory for the STE by Song et al. (1987). |
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