Tunable Intermediate-Logic Ternary Circuits based on MoSe2-WSe2 Heterojunction

Van der Waals (vdW) heterojunctions, which consist of p-type and n-type semiconductors, have provided new features for transition metal dichalcogenides (TMDs). In this work, a negative differential transconductance (NDT) transistor based on a MoSe 2 -WSe 2 heterojunction (MoSe 2 -WSe 2 H-TR) is proposed. The MoSe 2 -WSe 2 H-TR provides desirable device characteristics for ternary circuit operation with a switching behavior of off-state / p-type turn-on / NDT region / p-type turn-on. As a result, a 100% output voltage ( V OUT ) swing inverter can be achieved in a ternary inverter, which consists of the proposed MoSe 2 -WSe 2 vdW-H-TR and a MoS 2 floating-gate transistor. Furthermore, a tunable intermediate-logic ternary circuit operation is demonstrated by controlling the threshold voltage ( V TH ) in a pull-down n-type MoS 2 floating-gate transistor. We also investigated that a light-induced operation on the MoSe 2 -WSe 2 vdW-H-TR offers control of the V OUT amplitude at the intermediate-logic state. Based on the proposed MoSe 2 -WSe 2 vdW-H-TR, this work suggests a strategy to obtain a tunable ternary circuit, thus providing a new concept of heterojunction electronics using layered TMDs.