ABSTRACT Surface passivation plays a key role in determining the efficiency and operational stability of perovskite photovoltaics. Herein, we demonstrate an arc‐plated graphene (APG) deposition strategy designed for superior interfacial passivation. The adhesive and controllable thickness of the graphene layer flattens the perovskite surface with a reduction of grain boundaries, boosting the electron mobility to twice that of the pristine film. Due to hydrogen bond and π‐type interaction with perovskite, the surface defects are significantly suppressed and yield a minimized nonradiative voltage loss of 63.62 mV, driving the open‐circuit voltage ( V OC ) up to 1.21 V and efficiency to 25.68% in inverted solar cells. Notably, the inherent moisture resistance of the compact APG layer significantly enhances long‐term device stability, delivering an ultralow degradation rate of ∼0.0065% per hour over 2 000 h of continuous operation.
Xu et al. (Wed,) studied this question.