Thermo-evaporated pentacene and perylene as hole transport materials for perovskite solar cells

Thermo-evaporated organic semiconductors with suitable frontier molecular orbitals are potential hole transport materials (HTMs) for perovskite solar cells (PSCs), owing to their high crystallinity associated with high carrier mobility. In this study, we employ typical organic semiconductors, namely pentacene and perylene, as the HTMs in PSCs with an inverted structure. We gradually regulate the crystallographic morphologies of pentacene and perylene thin films by elevating the target substrate temperature from room temperature to 120 °C and 80 °C, respectively. We observe a clear dependence of the photovoltaic performance of inverted PSCs on the substrate temperature. We obtain the optimal power conversion efficiency (PCE) for pentacene and perylene at the substrate temperatures of 40 °C and 60 °C, respectively. The PSCs based on perylene show the best PCE of 13.5%, which is much higher that based on pentacene (5.7%). Perylene-based device shows better stability than PEDOT:PSS-based one. This study substantially deepens our knowledge regarding PSCs based on thermo-evaporated HTMs.