Photoelectrochemical and Corrosion Study of n‐Type SnSSe

Single crystals of n‐type obtained both by transport and Bridgman methods exhibit an energy gap of 1.53 eV. The flatband potential is p H dependent, and its values in acidic and alkaline solutions are, respectively, 0.06 and −0.6V (SCE). In the dark, is stable in acidic medium, but the stability decreases as p H increases. It is also unstable in acidic solutions containing the oxidizing form of a redox reagent with a sufficiently positive redox potential ( ca. more positive than 0.8V/SCE). The presence of an oxidizing form of a redox couple in alkaline medium enhances the already existing corrosion reaction. The corrosion reaction is accompanied with an anodic current. The corrosion rate as well as the magnitude of the anodic current depends on p H and the concentration of the oxidizing state of the couple. Light‐driven reactions in both acidic and alkaline media are corrosion reactions. However, decomposition may be avoided in acidic solution containing potassium iodide.