On the anodic decomposition of the zinc selenide electrode

The electrochemical decomposition of n-type zinc selenide has been studied in connection with the chemisorption of the OH^? groups onto the semiconductor surface, depending on the band bending. The influence of oxidizing agents such as the illumination of the electrode or the presence of ferricyanide ions in the solution, leading to injection of holes into the valence band, has also been put in evidence. In contrast with the usual decomposition models that are rather simple, a complex and multistep mechanism is proposed here in order to account for the different observations made on these electrodes: the triangular decomposition pits, the deep red layer of amorphous selenium and the bright grey layer of zinc oxide.