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The mechanism of the photoelectrochemical etching (photoetching) of normalCdSe was investigated. The products of the photoetching were analyzed by cyclic voltammetry in a 1.0M normalKCl solution. The layers were grown under various light intensities and solution pH. The influence of other variables, such as the potential of the working electrode and different solution compositions, was evaluated. Energy dispersive x‐ray spectroscopy (EDS) was used to analyze each stage of the process. The results provide further evidence to support our proposed mechanism. It was also found that the surface roughness increases considerably after photoetching. Two methods are described for the determination of the ratio of the surface areas of the chemically and photoelectrochemically etched electrodes. The experimental results are interpreted in terms of a five‐step reaction network. Fitting of the kinetic parameters by means of a computer simulation program produces good matching of the simulated and experimental i‐V curves.

Photoelectrochemical etching (photoetching) of many semiconductors leads to a pitted morphology with small etch pits (>109 cm−2) uniformly distributed over the entire semiconductor surface. It is shown here that the etch pit density increases with doping density and decreases with forward bias. These results suggest that charge flow within semiconductor junctions is highly nonuniform due to the existence of microscopic electric fields induced by the ionized donors within the space-charge layer. Numerical results for a set of CdSe and CdTe crystals are reported.

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