Surface engineering of FAPbI₃ based organic-inorganic hybrid perovskite for memristors

Organic-inorganic hybrid perovskites (OIHPs) have been spotlighted as emerging solution-processed electronics and show promise as economical, flexible, and stretchable emerging memristors. However, OIHPs suffer from considerable defects derived from solution processing; thus, post-processing is often required to alleviate such shortcomings. Treating alkyl ammonium organic salt on OIHP films is a representative approach to efficiently mediate the defect density. Here, we adopted n-octyl ammonium chloride (OACl) in our post-processing agent for organometal perovskite memristors (OPMs). The OACl-incorporated OPM showed an enlarged ON/OFF resistance ratio of 520 compared to OPM without passivation (3.91). Thin film analysis revealed that the synergistic insulating/passivating layer from OACl post-treatment retarded the interaction with the electroactive electrode (Ag). Additionally, the combined effects from the lower-dimensional OIHP induced by OA, including the p-doping of lead by chloride, enhanced the energetic barrier with Ag electrode to reduce the parasitic current at the high resistance state. This study offers deeper insights into the surface passivation of OIHPs and its effects on memristic performance.