Croatica Chemica Acta, Vol. 63 No. 3, 1990.
Conference paper
Kinetics and Mechanisms of Photoelectrochemical Reactions at Semiconductor Electrodes
Laurence M. Peter
; Department of Chemistry The University, Southampton S09 5NH Great Britain
Abstract
Some kinetic aspects of the photocurrent response of semiconductor electrodes are considered. Particular attention is given to surface recombination, which reduces the photocurrent conversion efficiency, and to photocurrent multiplication, which leads to quantum efficiencies greater than unity. The advantages of non steady-state photocurrent measurements are considered, and it is shown that the coupling of electron and hole fluxes via the surface leads to a characteristic time or frequency dependence of the photocurrent conversion efficiency. The principle of intensity modulated photocurrent spectroscopy (IMPS) is described, and its application is illustrated with several examples, including the reduction of oxygen at p-GaAs and the photooxidation of Si in NH4F. It is shown that frequency response analysis offers unique insights into complex photoelectrode processes of this kind.
Keywords
Hrčak ID:
137380
URI
Publication date:
28.12.1990.
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