Memristive switching in two-dimensional BiSe crystals

In spite of the explosive rise of research on memristive switching, more improvements in tunability, versatility, and hetero-integration are required through the discovery and application of novel materials. Herein, we report resistance switching in nano-thick two-dimensional (2D) crystals of bismuth selenium (BiSe). The BiSe devices exhibit nonvolatile bipolar resistance switching, volatile switching, and electrical bistable behavior in different conditions. The different memristive behavior of BiSe devices may be related to the concentration of Bi ions in this Bi-rich structure, which directly affects the capability of filaments forming. Furthermore, the external mechanical strain is applied in modulation of multi-layer BiSe devices. The memristive BiSe devices show a large on/off ratio of ~ 10⁴ and retention time of ~ 10⁴ s. The discovery of memristive switching behavior in multi-layer BiSe is attributed to the forming of Bi filaments. The resistance switching behavior in multi-layer BiSe demonstrates the potential application in the flexible memories and functional integrated devices.