Ultralow Off-State Current and Multilevel Resistance State in Van der Waals Heterostructure Memristors

作者：Liu, Xinling; Zhang, Chi; Li, Enlong; Gao, Caifang; Wang, Ruixue; Liu, Yu; Liu, Fucai^*; Shi, Wu; Yuan, Yahua; Sun, Jian^*; Lin, Yen-Fu^*; Chu, Junhao; Li, Wenwu^*

来源：Advanced Functional Materials, 2023.

DOI：10.1002/adfm.202309642

• h-BN interlayer
• memristors
• multilevel resistance states
• off-state current
• van der Waals heterostructure

Memristors based on 2D semiconductors hold great promise due to their atomic-level thickness and tunable optoelectronic properties. However, a significant challenge lies in suppressing the large off-state current, which leads to additional standby power consumption. Here, a simple and versatile method is presented to address this issue by introducing a thin h-BN interlayer between 2D semiconductors and the electrodes. The thickness of the h-BN interlayer serves as a pivotal parameter for modulating the interfacial Schottky barrier, thereby influencing the off-state current level. This fabricated graphene/alpha-In2Se3/h-BN/Cr-Au memristor, forming a van der Waals heterostructure, exhibits unipolar resistive switching behavior. Remarkably, the memristor incorporating an 8 nm h-BN interlayer showcases an ultralow off-state current of 4.2 x 10-13 A, five orders of magnitude lower than that without the h-BN interlayer. It also achieves a current switching on/off ratio of up to 109 and realizes 32 distinct resistance states, enabling robust multi-bit memory capabilities. Excellent stability and durability are maintained due to the self-encapsulation of the h-BN interlayer. Furthermore, this method is also applicable to memristors built on HfS2, WS2, and WSe2, highlighting its broad potential for technological applications. @@@ Owing to the atomic thickness, memristors based on 2D semiconductors show a high off-state current, which leads to additional power consumption. This work designs a versatile device structure to achieve an ultralow off-state current in alpha-In2Se3 memristors by incorporating a thin h-BN interlayer. It also realizes 32 distinct resistance states, enabling robust multi-bit memory capabilities.image

• 单位
  复旦大学; 电子科技大学