Molecular Synergistic Passivation for Efficient Perovskite Solar Cells and Self‐Powered Photodetectors

Abstract The interface between the perovskite and electron‐transporting material is often treated for defect passivation to improve the photovoltaic performance of devices. A facile 4‐Acetamidobenzoic acid (containing an acetamido, a carboxyl, and a benzene ring)‐based molecular synergistic passivation (MSP) strategy is developed here to engineer the SnO x /perovskite interface, in which dense SnO x are prepared using an E‐beam evaporation technology while the perovskite is deposited with vacuum flash evaporation deposition method. MSP engineering can synergistically passivate defects at the SnO x /perovskite interface by coordinating with Sn 4+ and Pb 2+ with functional group CO in the acetamido and carboxyl. The optimized solar cell devices can achieve the highest efficiency of 22.51% based on E‐Beam deposited SnO x and 23.29% based on solution‐processed SnO 2 , respectively, accompanied by excellent stability exceeding 3000 h. Further, the self‐powered photodetectors exhibit a remarkably low dark current of 5.22 × 10 −9 A cm −2 , a response of 0.53 A W −1 at zero bias, a detection limit of 1.3 × 10 13 Jones, and a linear dynamic range up to 80.4 dB. This work proposes a molecular synergistic passivation strategy to enhance the efficiency and responsivity of solar cells and self‐powered photodetectors.