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Author Fessenden, R. W. ♦ Hug, G. L. ♦ Kamat, P. V.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ PHYSICS ♦ SEMICONDUCTOR MATERIALS ♦ ELECTRON TRANSFER ♦ ABSORPTION SPECTRA ♦ ACTIVATION ENERGY ♦ THIN FILMS ♦ PHOTOCURRENTS ♦ DYES ♦ ORGANIC COMPOUNDS ♦ TIN OXIDES ♦ SENSITIZERS ♦ HYDROGEN ♦ CHEMICAL REACTION KINETICS
Abstract Adsorption of a cationic dye, cresyl violet, on SnO{sub 2} and SiO{sub 2} nanoclusters and nanocrystalline thin films results in the formation of H-aggregates. These dyes are photochemically and electrochemically active and extend the photoresponse of large bandgap semiconductors such as SnO{sub 2}. Photocurrent generation in dye capped nanocrystalline films of SnO{sub 2} has been demonstrated with visible light excitation. A photon-to-photocurrent generation efficiency around 1% has been observed at 510 nm. Back electron transfer between the photoinjected electron and the oxidized sensitizer plays an important role in controlling the efficiency of net electron transfer. Transient absorption and microwave absorption measurements of the dye aggregate capped SnO{sub 2} films suggest that the back electron transfer is multiexponential and most is completed within a few hundred nanoseconds. The activation energy of the back electron transfer process is very low (nearly 1.7 kJ/mol). 68 refs., 10 figs.
ISSN 10895647
Educational Use Research
Learning Resource Type Article
Publisher Date 1997-04-03
Publisher Place United States
Journal Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
Volume Number 101
Issue Number 14


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