The effect of Ar plasma etching time on the microstructure, optical and photoelectric properties of CdZnTe films

• CdZnTe films were treated by Ar plasma etching process with various etching time.
• The structure and surface roughness of the film was closely related to etching time.
• The CdZnTe film with 5 min plasma etching showed lower dark-current.
• CdZnTe films with 5 min plasma etching showed better photo-response to UV light.

In this work, Ar plasma etching was performed to polycrystalline CdZnTe thick films grown from close-spaced sublimation method. The effect of Ar plasma etching time on the microstructure, optical and photoelectric properties of CdZnTe films were investigated by using AFM, XRD, UV–visible spectrophotometer and current-voltage characterization system. The results showed that proper plasma etching time can significantly improve the surface roughness and passivate the CdZnTe film surface, leading to less surface leakage current and higher photo-response of the Au/CdZnTe/FTO photo-conductive structure. Its photo-response sensitivity under 281 nm UV irradiation increases with one order of magnitude after 5 min' etching.