The stability of single crystal photoelectrodes in polysulfide electrolyte is shown to be a function of the etching treatment used. This is explained by changes in real electrode surface area caused by different etchants, leading to a variation in real photocurrent density. The effect of photocurrent density on stability is measured, and used to semiquantitatively explain the observed variation in stability with etching. The effect is shown to be consistent for three different crystal faces, and is extended to polycrystalline electrodes.