Investigations of structural, morphological and optical properties of Cu: ZnO/TiO2/ZnO and Cu: TiO2/ZnO/TiO2 thin films prepared by spray pyrolysis technique

The aim of this research work is presented a comparison study of Cu:ZnO/TiO2/ZnO (Cu:ZTZ) and Cu: TiO2/ZnO/TiO2 (Cu:TZT) thin films deposited by spray pyrolysis technique on FTO substrates. After deposition, these films are annealed at 500 degrees C.XRD confirms the anatase phase of TiO2 and Hexagonal wurtzite phase of ZnO. SEM shows that Cu:TZT has more porous surface than Cu:ZTZ and also the root mean square (RMS) roughness of Cu:TZT film is 48.96 and Cu:ZTZ film is 32.69. The calculated optical band gaps of Cu:TZT and Cu:ZTZ thin films are 2.65 eV and 2.6 eV respectively, measured by UV-Vis spectrophotometer. This work provides an environment friendly and low cost use of an abundant material for highly efficient dye sensitized solar cells (DSSCs). (C) 2017 The Author. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.