Electrodeposited thin films of CdTe and CdxHg1−xTe with 1 − x = 0 and approximately 0.1 were characterized by x-ray photoelectron spectroscopy. The composition of the bulk and the thickness and composition of the native surface oxide before and after Ar+ ion sputtering were determined. A surface oxide layer 20-Å thick constituted mainly of alloyed TeO2 and CdO was found over a nearly stochiometric bulk. Chemical diffusion of Hg, Cd, and Te to the surface was observed. Hg appears to inhibit oxidation of the telluride, mainly of Te. Ar sputtering removed undesirable oxides and impurities off the films.