Optimization of ZnO thin film through spray pyrolysis technique and its application as a blocking layer to improving dye sensitized solar cell efficiency

• Zno thin film deposition by spray pyrolysis, spin coating and dip coating techniques and comparison between them.
• Achieving better quality for thin film by spray pyrolysis.
• Investigation of effective parameters on films quality in spray pyrolysis deposition and optimization of these parameters.
• Increasing cell efficiency by using this thin film as a blocking layer in DSSC.

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 Jsc increases from 12.63 mA/cm2 to 15.60 mA/cm2 and efficiency was 20% higher than that of the cell without the blocking layer.