Photo-Induced Doping to Enable Tunable and High-Performance Anti-Ambipolar MoTe2/MoS2 Heterotransistors.

Van der Waals (vdW) p-n heterojunctions formed by two dimensional nanomaterials exhibit many physical properties and deliver functionalities to enable future electronic and optoelectronic devices. In this report, we demonstrate a tunable and high-performance anti-ambipolar transistor based on MoTe2/MoS2 heterojunction through in situ photo-induced doping. The device demonstrates high on/off ratio of 105 with large on-state current of several micro-Amps. Peak position of the drain-source current in the transfer curve can be adjusted through doping level across a large dynamic range. In addition, we have fabricated a tunable multi-value inverter based on the heterojunction that demonstrates precise control over its output logic states and window of mid-logic through source-drain bias adjustment. The heterojunction also exhibits excellent photo detection and photovoltaic performances. Dynamic and precise modulation of the anti-ambipolar transport properties may inspire functional devices and applications of two-dimensional nanomaterials and their heterostructures of various kinds.