ZnO thin films have been deposition with three techniques, spray pyrolysis, spin coating and dip coating. Based on results of UV, XRD, four-probe resistance and ellipsometry analysis, the spray pyrolysis technique was the best one. In order to optimize the thin film deposition, the temperature and the height parameters were investigated. For the first time the thin film prepared by this technique was used as a blocking layer between FTO/TiO2 in dye sensitized solar cell. By employing the blocking layer J(SC) increases from 12.63 mA/cm(2) to 15.60 mA/cm(2) and efficiency was 20% higher than that of the cell without the blocking layer. (C) 2015 Elsevier B.V. All rights reserved.