Multifunctional small molecule interface management for efficient planar perovskite solar cells†

Establishing an optimal configuration for the electron transport layer (ETL) and a compliant perovskite interface is pivotal in advancing the creation of high-performance, hysteresis-free, and resilient perovskite solar cells (PSCs). Amongst various strategies, interface engineering emerges as a highly feasible and potent means to alleviate interfacial non-radiative recombinations, issues typically rooted in defects, tensile stresses, and energy level discrepancies at the interface. Our investigation solidifies the efficacy of incorporating Imidazolium Salt (NOI:1N-3-acetic acid-imidazole) within the SnO₂/perovskite interface as a strategic intervention for remodeling this vital frontier. The integration of NOI fosters a synergistic interface, seamlessly bridging the perovskite with the SnO₂ ETL, effectively mitigating tensile strains and passivating underlying interface defects. Implementation of the NOI-based treatment regimen has notably propelled device performance, evidenced by a PCE escalation from 21.5% to 23.3%, coupled with a marked increase in open-circuit voltage (V_OC) from 1.15 V to 1.18 V. Consequently, this methodology presents a concise yet powerful pathway for augmenting PSCs' operational excellence.