Synergistic interface and compositional engineering of inverted perovskite solar cells enables highly efficient and stable photovoltaic devices

Recently, interface and compositional engineering have been effective approaches in the field of perovskite solar cells (PSCs). In this work, the surface of the nickel oxide layer and perovskite composition are modified by poly[(9,9-bis(30-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] dibromide (PFN-P2) and deionized (DI) water, respectively, which result in a device with 20.5% efficiency and great stability.