Robust and Transient Write‐Once‐Read‐Many‐Times Memory Device Based on Hybrid Perovskite Film with Novel Room Temperature Molten Salt Solvent

Abstract Organic–inorganic hybrid perovskites (OIHPs) have emerged as a novel class of functional materials with applications in solar cells, photodetectors, light‐emitting diodes, and resistive switching memories. Generally, perovskite films are fabricated with toxic solvents and antisolvent technique under inert atmosphere, which limits the commercial applications of OIHP‐based devices. To address this issue, uniform CH 3 NH 3 PbBr 3 (MAPbBr 3 ) film is fabricated through a facile one‐step spin‐coating method by directly dissolving perovskite precursor in a room‐temperature molten salt methylammonium acetate under air ambient condition. The nonvolatile resistive switching devices based on MAPbBr 3 exhibit robust and reproducible write‐once‐read‐many‐times (WORM) memory properties with a large ON/OFF ratio (10 6 ), reliable retention properties (10 4 s), and somewhat ternary resistive characteristic. The conductive filaments in the perovskite thin film are proposed to induce the electrical conductivity switching. Additionally, the MAPbBr 3 films can be dissolved rapidly in deionized water within 5 s, showing the transient characteristics. This work demonstrates a new perspective on the perovskite film fabrication and shows the potential application of MAPbBr 3 in transient WORM devices.