Effect of copper on composition, structural and optical properties of copper doped ZnTe thin films

Abstract

Ultrathin (250 Å) initial deposit of copper on glass substrates were used for the subsequent deposition of ZnTe films under a pressure of 10-5 m.bar by thermal evaporation method. The decrease of atomic percentage of copper with increase of the ZnTe film thickness is confirmed by EDAX analysis. The phase change from hexagonal to cubic structure is observed by XRD analysis. The strain (ε), grain size (D) and dislocation density (ρ) were calculated and results are discussed. The transmittance and the optical bandgap energy were found decreases when increases of ZnTe film thickness. The optical transition of these films is found to be direct allowed. © 2013 VBRI press.