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Title: Photocarrier dynamics in anatase TiO{sub 2} investigated by pump-probe absorption spectroscopy

The dynamics of photogenerated electrons and holes in undoped anatase TiO{sub 2} were studied by femtosecond absorption spectroscopy from the visible to mid-infrared region (0.1–2.0 eV). The transient absorption spectra exhibited clear metallic responses, which were well reproduced by a simple Drude model. No mid-gap absorptions originating from photocarrier localization were observed. The reduced optical mass of the photocarriers obtained from the Drude-model analysis is comparable to theoretically expected one. These results demonstrate that both photogenerated holes and electrons act as mobile carriers in anatase TiO{sub 2}. We also discuss scattering and recombination dynamics of photogenerated electrons and holes on the basis of the time dependence of absorption changes.
Authors:
; ; ; ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [5] ;  [1] ;  [6]
  1. Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561 (Japan)
  2. (HIT), Harbin City 150080 (China)
  3. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8562 (Japan)
  4. Department of Applied Physics and Quantum Phase Electronics Center (QPEC), University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan)
  5. (QPEC), University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan)
  6. (Japan)
Publication Date:
OSTI Identifier:
22278116
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; CHARGE CARRIERS; COMPARATIVE EVALUATIONS; ELECTRONS; HOLES; INFRARED SPECTRA; RECOMBINATION; TIME DEPENDENCE; TITANIUM OXIDES; VISIBLE SPECTRA