Interfacial Dipole-Induced High Open-Circuit Voltage for Efficient Perovskite Solar Cells

Solution-processed perovskite films frequently exhibit a high density of defects at their surfaces and grain boundaries, leading to significant nonradiative recombination, hysteresis, and energy losses. Interfacial modification is a crucial strategy for enhancing the photovoltaic performance of perovskite solar cells. In this study, we introduce a polar molecule 3,3,3-trifluoropropionamide (TFAN) with a permanent dipole moment to modify the surface of perovskite films, effectively passivating the uncoordinated Pb²⁺. The results demonstrate that appropriate interfacial modifications can significantly reduce trap state density and suppress nonradiative recombination, thereby facilitating efficient charge transfer. Without sacrificing photocurrent, the efficiency of TFAN-modified perovskite films increased from 22.21% to 25.17%, while the open-circuit voltage rose from 1.14 to 1.23 V. These enhancements substantially improved the photovoltaic parameters and greatly enhanced operational stability.