An analytical formulation for the J( V) characteristics of a photoelectrolytical cell

Abstract

An analytical formulation is given in the present work for the study of the electrical characteristics of an ideal photoelectrolytical cell utilizing an n-type, wide band gap semiconducting electrode. Recombinations both at the surface and in the depletion layer are included and a model is suggested that accounts for the statistical effects in the transfer process of electrical charges at the semiconductor-electrolyte interface. An equation is obtained for the total hole current in which the different contributions from the various recombination processes are easily recognizable and the energy distribution of surface states and recombination levels are explicitly taken into account. A detailed numerical analysis of equations shows the correlation between the photocurrent near its onset and the slope of the J( V) curves with the parameters that characterize each one. A possible dependence of photocurrent on light radiation intensity is given and tunnel currents at the semiconductor-electrolyte interface are included in the model.