Wu Fan, Tian He, Yan Zhaoyi, Ren Jie, Hirtz Thomas, Gou Guangyang, Shen Yang, Yang Yi, Ren Tian-Ling
Institute of Microelectronics and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China.
ACS Appl Mater Interfaces. 2021 Jun 9;13(22):26161-26169. doi: 10.1021/acsami.1c03959. Epub 2021 May 25.
Two-dimensional (2D) heterostructures show great potential in achieving negative differential resistance (NDR) effects by Esaki diodes and or resonant tunneling diodes. However, most of the reported Esaki diode-based NDR devices realized by bulk 2D films lack sufficient gate tunability, and the tuning of NDR behavior from appearing to vanishing remains elusive. Here, a gate-tunable NDR device is reported based on a vertically stacked black phosphorus (BP) and molybdenum disulfide (MoS) thin 2D heterojunction. At room temperature, a rectifying ratio of ∼6 orders of magnitude from a reverse rectifying diode to a forward rectifying diode by gate modulation is obtained. Through analyzing the temperature-dependent electrical properties, the tunneling mechanism at a certain gate voltage range is revealed. Moreover, the switchable and continuously gate-tunable NDR behavior is realized with a maximum peak-to-valley ratio of 1.23 at 77 K, as shown in the mappings by sweeping under different . In addition, a compact model for gate-tunable NDR behavior in 2D heterostructures is proposed. To our best knowledge, this is the first demonstration of NDR behavior in BP-MoS heterostructures. Consequently, this work sheds light on the gate-tunable NDR devices and reconfigurable logic devices for realizing ternary and reconfigurable logic systems.
二维（2D）异质结构在通过江崎二极管和/或共振隧穿二极管实现负微分电阻（NDR）效应方面显示出巨大潜力。然而，大多数通过体二维薄膜实现的基于江崎二极管的NDR器件缺乏足够的栅极可调性，并且NDR行为从出现到消失的调节仍然难以捉摸。在此，报道了一种基于垂直堆叠的黑磷（BP）和二硫化钼（MoS）薄二维异质结的栅极可调NDR器件。在室温下，通过栅极调制获得了从反向整流二极管到正向整流二极管约6个数量级的整流比。通过分析温度依赖的电学性质，揭示了在一定栅极电压范围内的隧穿机制。此外，在77 K时实现了可切换且连续栅极可调的NDR行为，最大峰谷比为1.23，如在不同条件下扫描的映射图所示。此外，还提出了二维异质结构中栅极可调NDR行为的紧凑模型。据我们所知，这是首次在BP-MoS异质结构中展示NDR行为。因此，这项工作为实现三元和可重构逻辑系统的栅极可调NDR器件和可重构逻辑器件提供了启示。
