Zinc Oxide is actively investigated for hybrid organic inorganic device applications. The interface greatly influences the electronic properties of these devices. Molecular surface modification of ZnO is being investigated for its potential to control the alignment of energy levels, charge transfer, as well as, interfacial chemical characteristic influence device fabrication. In this study, The influences of buffer layers on the performance of hybrid solar cells that are fabricated with an active layer blend of poly (3-hexylthiophene) (P3HT) and [6, 6]-phenyl-C61-buytyric acid methylester (PCBM). The ZnO thin films were used as an electron transport layer in solar cells to improve the photovoltaic performances.. We fabricated ITO glass on PET substrate, consist of Au/MoO3/PCBM:P3HT/ZnO/ITO. Solar cell conversion efficiency in which the ZnO nanorods shapes were controlled ZnO nanorods arrays under concentration of precursors were compared respectively. We conclude that the differences observed in the two types of device predominantly arise from changes in interfacial dipoles, and intermediate materials processing can be critical to solar cell performance.