Relationship between stabilization and photocurrent at n-type semiconductor electrodes on the basis of a model including surface recombination through decomposition intermediates

Abstract

Following the recent publication of preliminary experimental results, a general kinetic discussion is presented for competing anodic decomposition, stabilization and surface recombination processes at illuminated n-type semiconductor electrodes, assuming that surface recombination occurs through reaction intermediates of the decomposition process and that the stabilization reaction either also occurs through such intermediates or involves free holes. The relationship between the stabilization ratio and the total photocurrent is investigated theoretically under varying light intensity, surface conduction-band electron concentration or stabilizing agent concentration, with special attention to the limiting cases. The results are discussed in terms of their mechanistic background and from the viewpoint of their implications to practical photoelectrochemical cells.