Effects of surface treatments on Schottky barrier formation at metal/n-type CdTe contacts

Abstract
The nature of n‐CdTe surfaces prepared by various chemical treatments has been studied by x‐ray photoelectron spectroscopy. In parallel experiments Schottky barrier heights have been measured for Sb and Au contacts deposited on surfaces prepared in an identical manner. Reducing etches are found to leave the surface rich in Cd, and for these surfaces Sb and Au always produce barrier heights of 0.93±0.02 eV. Bromine in methanol solutions leaves the surface rich in Te and gives rise to two valued barrier heights of 0.93 and 0.72 eV. It is found that the probability of generating contacts with the higher value of barrier height increases as the surface becomes richer in Cd.