Reversible Charge-Polarity Control for Multioperation-Mode Transistors Based on van der Waals Heterostructures

Van der Waals (vdW) heterostructures—in which layered materials are purposely selected to assemble with each other—allow unusual properties and different phenomena to be combined and multifunctional electronics to be created, opening a new chapter for the spread of internet-of-things applications. Here, an O₂-ultrasensitive MoTe₂ material and an O₂-insensitive SnS₂ material are integrated to form a vdW heterostructure, allowing the realization of charge-polarity control for multioperation-mode transistors through a simple and effective rapid thermal annealing strategy under dry-air and vacuum conditions. The charge-polarity control (i.e., doping and de-doping processes), which arises owing to the interaction between O₂ adsorption/desorption and tellurium defects at the MoTe₂ surface, means that the MoTe₂/SnS₂ heterostructure transistors can reversibly change between unipolar, ambipolar, and anti-ambipolar transfer characteristics. Based on the dynamic control of the charge-polarity properties, an inverter, output polarity controllable amplifier, p-n diode, and ternary-state logics (NMIN and NMAX gates) are demonstrated, which inspire the development of reversibly multifunctional devices and indicates the potential of 2D materials.