AN ANALYTICAL DESCRIPTION OF THE CONSEQUENCES OF ABANDONING THE PRINCIPLES OF DETAILED BALANCE AND MICROSCOPIC REVERSIBILITY IN SEMICONDUCTOR PHOTOELECTROCHEMISTRY
Ga. Shreve et Ns. Lewis, AN ANALYTICAL DESCRIPTION OF THE CONSEQUENCES OF ABANDONING THE PRINCIPLES OF DETAILED BALANCE AND MICROSCOPIC REVERSIBILITY IN SEMICONDUCTOR PHOTOELECTROCHEMISTRY, Journal of the Electrochemical Society, 142(1), 1995, pp. 112-119
Key differences between the conventional and ''irreversible'' models o
f semiconductor photoelectrochemistry are identified and discussed wit
hin the framework of experimental observations. Conceptual differences
between these two models appear to lie in the treatment of interfacia
l charge-transfer processes for photogenerated charge carriers. The co
nventional model utilizes detailed balance principles for obtaining ra
te constant relationships for all interfacial charge-transfer events a
t semiconductor/liquid contacts and uses the principle of microscopic
reversibility to evaluate these rate constants for situations away fro
m equilibrium. In contrast, the irreversible model postulates that loc
al statistical detailed balance does not apply to charge-transfer even
ts in photoelectrolysis, and that such charge-transfer events are high
ly irreversible, like photoemission into a vacuum. It is shown analyti
cally that the two models predict differences in the behavior of the a
vailable free energy produced by a photoelectrochemical cell at a fixe
d incident Light intensity. The conceptual implications of these diffe
rences are evaluated analytically and are also compared to experimenta
l results for semiconductor/liquid junctions.