Gate-Tunable Negative Differential Resistance Behaviors in a hBN-Encapsulated BP-MoS₂ Heterojunction

Abstract

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 (MoS2) 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 I DS mappings by sweeping V DS under different V GS. 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-MoS2 heterostructures. Consequently, this work sheds light on the gate-tunable NDR devices and reconfigurable logic devices for realizing ternary and reconfigurable logic systems.

Two-Dimensional GeC2 with Tunable Electronic and Carrier Transport Properties and a High Current ON/OFF Ratio

“…The current ON/OFF ratio amounts to 10 5 . Moreover, at 4% strain, significant NDC (the maximum I peak / I valley in the order of 10 4 ) arises under the bias range from 0.1 to 0.5 V and from −0.5 to −0.1 V, higher than the NDC of several other 2D materials and heterojunctions. ,− For BL tetrahex-GeC 2 , the current also exhibits anisotropy in the bias voltage range from −0.5 to 0.5 V, and NDC is also present.…”

Negative Differential Resistance in Oxygen-ion Conductor Yttria-stabilized Zirconia for Extreme Environment Electronics

“…Our YSZ device exhibits N-type NDR behavior between −1.3 V and −2 V with a peak-to-valley current ratio (PVCR) of 5.8 at 543 K (Figure a), which is among the highest operating temperatures in comparison to previously reported NDR devices. − The PVCR is a key performance metric in typical NDR devices. In terms of electrochemically induced NDR, PVCR values can increase until saturation by increasing the scan rate (Figure S10).…”

“…Figure e presents a comparison between our YSZ device and literature reports of other systems. − Typical N-type NDR devices include the Esaki diode, resonant tunneling diode, Gunn diode, single-electron transistor, and molecular devices that are interesting for applications such as selectors for crossbar memory arrays, amplifiers, threshold switches, and chaotic circuit elements . As discussed above, significant ionic transport and coupled interfacial reactions along with polarity dependence provide a new degree of freedom in terms of modulation of electrical conduction behaviors especially at high temperatures.…”

The non-volatile electrostatic doping effect in MoTe2 field-effect transistors controlled by hexagonal boron nitride and a metal gate

“…2 a. Upon further increasing the writing voltage, the MoTe 2 region above the localized metal gate became completely n-type at a − 10 V writing voltage 58 – 60 . In addition, higher writing voltages resulted in more positive charges on the h-BN flake, which eventually provided an additional positive gate voltage.…”