Resistive Switching Property of Organic-Inorganic Tri-Cation Lead Iodide Perovskite Memory Device

In this study, a glass/indium tin oxide (ITO)/formamidinium-methylammonium-cesium (FA-MA-Cs) tri-cation lead iodide perovskite/poly(methyl methacrylate (PMMA)/Al memory device with a controlled composition of (FA MA ) Cs PbI (x = 0-0.1) is demonstrated to exhibit bipolar resistive switching behavior. The tri-cation organic-inorganic metal halide perovskite film was prepared by a one-step solution process in which the amount of Cs was varied to modify the property of FA MA PbI . It was found that the microstructure and defect properties of films are highly dependent on the contents of FA, MA, and Cs in the perovskite. The results found that 5% CsI doping is the optimized condition for improving the quality of FA MA PbI , forming a high quality tri-cation perovskite film with a smooth, uniform, stable and robust crystalline grain structure. The resistive switching on/off ratio of the (FA MA ) Cs PbI device is greater than 10 owing to the improved thin-film quality. Moreover, for the 5% CsI doped FA MA PbI films, the endurance and the stability of retention are better than the non-doped film. The improved microstructure and memory properties are attributed to the balance stress of FA/MA/Cs with different ionic size. It suggests the potential to achieve a desired resistive memory property of tri-cationic perovskite by carefully adjusting the cation ratios.