As the fossil fuels that are currently being used are depleted, renewable energy industry recently has become active. And the one of renewable energy is solar cells. Especially, Organic solar cell (OSC) is a one of effective ways to convert solar source to electrical energy. Recently, many researchers have tried to achieve higher power conversion efficiency (PCE) of OSC by developing new semiconducting materials. In this study, we design the new small molecules with organic hydroxyl groups and intercalate between ZnO layer and active layer. Herein, hydroxyl groups induce the favorable interface dipole for these electron transfer layer (ETL) to enhance PCE. And we investigate the effect of interface dipole from hydroxyl groups on photovoltaic parameters.