Controlling the Grain Size of Dion-Jacobson-Phase Two-Dimensional Layered Perovskite for Memory Application.

Organic-inorganic halide perovskites (OIHPs) have emerged as an active layer for resistive switching memory (RSM). Among various OIHPs, two-dimensional OIHPs are advantageous in RSMs because of their stability. This stability can be further improved using two-dimensional Dion-Jacobson OIHPs. Moreover, OIHP-based RSMs operated by the formation of halide-ion filaments are affected by grain boundaries because they can act as a shortcut for ion migration. Therefore, it is essential to control the grains in OIHPs for reliable memory operation. Here, we present RSMs using Dion-Jacobson OIHP with controlled grain sizes. The grain sizes of the OIHP are effectively controlled by adjusting the ratio of the N,N-dimethylformamide and dimethyl sulfoxide. The controlled grain sizes can modulate the paths for halide ion migration, which enables the change of the on/off ratio in RSM. In addition, cross-point array structure is essential for high-density memory applications. However, in the cross-point array structure, unwanted current flow through unselected memory cells can happen due to sneak-current paths, so it is necessary to suppress leakage current from neighboring cells by adopting selector devices. We demonstrate the application of selector devices to OIHP-based RSMs to prevent sneak current paths. These results provide the potential of OIHP for use in high-density memory applications.