Enhancing Efficiency and Stability of Perovskite Solar Cells via a Self-Assembled Dopamine Interfacial Layer

Interfacial engineering is a simple and effective strategy that can improve the photovoltaic performance in organic-inorganic perovskite solar cells (PSCs). Herein, a dopamine (DA) self-assembled monolayer (SAM) was introduced on the top of the SnO₂ electron transporting layer (ETL) to modify the SnO₂/perovskite interface. The processing temperature of the present devices is around 150 °C, and the power conversion efficiency of the PSCs was significantly improved to 16.65% compared to that of the device without modification (14.05%). Such enhancement in efficiency is mainly attributed to the improved quality of perovskite films by improving the affinity of the SnO₂ ETL, thus leading to better carrier transport and low charge recombination at the SnO₂/perovskite interface. Moreover, the modified device by the DA SAM exhibited enhanced stability compared to the device without modification. Our results suggest that the introduction of the DA SAM on the ETL/perovskite interface is a promising method for highly efficient and stable PSCs.