Charge transmission of MoS2/MoTe2 verticalheterojunction and its modulation br

The heterojunction device based on two-dimensional materials possesses unique photoelectric properties dueto its nanoscale thickness and van der Waals (vdWs) contact surface. In this paper, a gate-voltage-tunableMoS2/MoTe2 vertical vdWs heterojunction device is constructed. The Kelvin probe force microscopy (KPFM)technology is combined with the electric transport measurement technology, thereby revealing the chargetransport behavior of the MoS2/MoTe2 heterojunction under dark condition and laser-irradition condition,including the bipolarity characteristics of the transition from n-n+ junction to p-n junction. In this paper, thecharge transport mechanism of heterojunction is explained comprehensively and systematically, including thecharge transmission process of n-n+ junction and p-n junction under positive and negative bias conditions, thetransformation of nodule behavior with gate voltage, the influence of barriers on charge transmission, thedifferent rectification characteristics between n-n+ junction and p-n junction, the major role of source andleakage bias voltage in band tunneling, and the influence of photogenerated carriers on electrical transmission.The method in this work can be generalized to other two-dimensional heterojunction systems and also providean important reference for improving the performance of two-dimensional semiconductor devices and theirapplications in the future