LAUSR

Abstract Surface electrical properties is of great significance for developing high-performance organic-inorganic hybrid perovskite based electronic devices. The photovoltage-induced ions transport and redistribution at the surface region have been well studied, but their contributions to the surface electrical properties are still lack of experimental evidences. In this article, a self-powered polymer-based contact electrification probe (PCE-probe) is proposed to investigate the photovoltage- or applied bias-induced ion transport polarization (PI) and ferroelectric polarization (PF) inside the methylammonium lead iodide films (MAPI). Results show that both the PI- and PF-induced ion transport and redistribution create a similar local ion-doping region near the surface. Positive or negative ion-doping produces a n-type or p-type layer, which enhances the interficial junction inside MAPI-based solar cells and benefits the seperation and transfer of photogenerated carriers or excitons. The PI and PF effects can be added up or subtracted from each other depending on the polarization configuration. A qualitative relationship between the PCE-probe output and CE-effect, PI- and PF-induced transferred surface charges is investigated. These results can help to understand the polarization nature inside and the high power conversion efficiency of MAPI-based photovoltaic devices, and provide a feasible analysis method of PCE-probe for detecting surface electrical properties.