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https://hdl.handle.net/2115/62197

Spectroscopic Photoresponse of the Passive Film Formed on Iron

英語

photoelectrochemistry

1986-07

The Electrochemical Society

J. Electrochemical Society

133(7)

1326-1328

Spectroscopic photoresponse of the passive film formed on iron in neutral borate solution was studied. The spectroscopic three parameter reflectometry and the photoelectrochemical technique were employed to obtain the spectra of absorption coefficient and photocurrent. From these spectra, a conversion efficiency, η, from the flux of photons absorbed in the film to the photocurrent was calculated as a function of photon energy. The result shows that the photoexcitation process of electron-hole-pair formation includes two transition mechanisms; a direct allowed transition and an indirect allowed transition. The direct transition, which occurs in the photon energy higher than 2.6 eV, is attributed to the excitation between the valence (O-2p) and the conduction (Fe-3d) bands of iron oxide, whereas the indirect transition, which occurs in the photon energy higher than 0.8 eV, is associated with electronic levels of impurities or d-d transition in the passive film. The maximum value of V observed at a photon energy of 3.1 eV is about 20%, and this high efficiency suggests that the high electric field exists in the passive film of iron.

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© The Electrochemical Society, Inc. 1986. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in J. Electrochem. Soc. 1986 volume 133, issue 7, 1326-1328 .

0013-4651

1945-7111