Synergistic passivation of defects for inorganic perovskite solar cells with reduced open-circuit voltage deficiency

Full-inorganic CsPb(I x Br 1- x ) 3 (0 <  x  < 1) optoelectronic devices have given rise to widespread interest of researchers owing to their excellent photovoltaic properties and promising thermal stability. However, defects at the interface between the electron transport layer (ETL) and the perovskite layer cause the open-circuit voltage ( V OC ) deficiency for inorganic perovskite solar cells (PSC). In this work, Baclofen (BCF), with carboxy group, amidogen group, and Cl in its molecule, is used as an interlayer between SnO 2 and CsPb(I x Br 1- x ) 3 inorganic perovskite. It is proved that the BCF can not only be beneficial for the growth of perovskite film but also act as a passivation layer for the SnO 2 /perovskite (PSK) interface, which significantly improves the open-circuit voltage of PSCs. Finally, a high V OC of 1.31 V and a power conversion efficiency (PCE) of 15.36% are realized for our BCF-treated PSCs.