Tunable Current Regulative Diode Based on Van der Waals Stacked MoS2/WSe2 Heterojunction–Channel Field‐Effect Transistor

Abstract Field‐effect transistors (FETs) are the main building block of microelectronic devices. For most of the FETs, the conduction channel relies on either n‐type or p‐type semiconductor materials. Recent advances in 2D materials offer an opportunity to form van der Waals heterojunction‐based FETs with novel electrical performance. Here, a MoS2/WSe2 heterojunction–channel FET using h‐BN as insulating layer and Cr/Au metal as the gate, is demonstrated. Two asymmetric Schottky contacts are formed at both sides of MoS2, WSe2 due to electron tunneling effects, work function differences, and Fermi level pinning. Benefiting from that, the authors observe a forward current regulating diode behavior, where the drain current remains unchanged regardless of the drain voltage (VDS) fluctuations and can be modulated by the gate voltage, atmosphere temperature, vacuum pressure, and h‐BN layer thickness. In addition, under higher VDS, heterojunction–channel breakdown induced by the Fowler–Nordheim (F–N) tunneling at the WSe2/h‐BN/metal region, is observed. Furthermore, the transistor demonstrates a reverse rectification behavior with onset voltage linearly depending on the temperature (3 mV T−1). This work paves the way for the potential application of heterojunction–channel FETs for high‐performance current regulator and current rectifier.