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In this research, quantum dot-sensitized solar cells QDSSCs based on ZnO nanorods. Due to the challenges in these types of cells such as ZnO weak conductivity, because of high recombination at the electrolyte-quantum dots QDs interface and weak electron transfer from QDs to ZnO, several experiments and improvement are performed on the photo anode. In order to improve the electron transfer and reduce the recombination at the electrolyte-QDs interface, two blocking layers have been utilized. The obtained results show that with the comparison between two blocking layers ZnO/CdS/ZnS and ZnO/CdS/AL2S3, the cell efficiency equal to 1.28 and 1.24 respectively, the open circuit voltage equal to 0.67 and 0.67 volts respectively, the open circuit current density equal to 3.86 A and 3.75 A respectively, and the filling factor equal to 48.6 and 49.3 respectively are obtained. We find here that due to the reduction of light absorption and the electron-hole recombination, the ZnS blocking layer yields higher efficiency 1.28 in comparison with the Al2S3 1.24 .