[Study on ZnTe (Znte:Cu) polycrystalline films by XPS]

ZnTe and ZnTe: Cu polycrystalline films were fabricated by means of co-evaporating at room temperature. The relationships between conductivity of the films and temperature were measured. Chemical compositions of ZnTe and ZnTe: Cu polycrystalline films were obtained by using XPS, and the changes of chemical composition before and after anneal were analyzed. The results showed that the conductivity of ZnTe rose linearly with the temperature, and Te was enriched on the margin of every sample's surface; With the rise in temperature, the conductivity of ZnTe: Cu films became abnormal, the oxidization of Te became very obvious and Zn diffused from the bulk to the surface. The composition became more uniform and all peaks became stronger. Carrier concentration caused by CuxTe appeared, resulting in the abnormal relationship between conductivity of the films and temperature.