Tunable interfacial electronic properties and contact types in 2D AuS/m-TMD heterostructures

Abstract The overall performance of a nanodevice is particularly sensitive to the contact properties at the interface between the two-dimensional (2D) channel material and the metallic electrode. Recently reported 2D semiconducting gold sulfide (AuS), which exhibits with superior oxidation resistance and high carrier mobility, shows great potential as a channel material for innovative applications in electronics. In this study, we systematically investigated the interfacial electronic properties and contact types of AuS in conjunction with various metallic transition metal dichalcogenides (m-TMDs) using first-principles calculations. T-VTe2, T-TaSe2, T-TiTe2, T-CoTe2, T-NbSe2, and T-TaS2 possess lower work functions (4.62–5.05 eV), enabling them to form n-type Schottky contacts with AuS. In contrast, T-NbS2 and T-TiTe2, which have higher work functions (5.31–6.06 eV), form p-type Schottky contacts with AuS. Additionally, H-TaSe2, H-NbSe2, H-TaS2, and H-NbS2 establish p-type Ohmic contacts. The tunneling probabilities of AuS/m-TMDs heterostructures range from 4.44% to 23.38%. Furthermore, the n-type Schottky contact of AuS/T-TaSe2 transitions to an n-type Ohmic (or p-type Schottky) contact under a biaxial strain of ⩽ −4.57% (or an interlayer distance difference of ⩽ −0.47 Å). Additionally, the p-type Ohmic contact of AuS/H-TaSe2 (and AuS/H-NbSe2) can be converted to a p-type Schottky contact with an interlayer distance difference of ⩾ 0.13 Å (0.24 Å), a biaxial strain of ⩽ −1.18% (−1.76%), or an external electric field of ⩽ −0.03 V Å−1 (−0.28 V Å−1 ). The tunneling probabilities of AuS/m-TMDs heterostructures vary significantly with decreasing interlayer distance, while they remain relatively constant when subjected to biaxial strain or an external electric field. Our findings suggest that the contact types and tunneling probabilities of AuS/m-TMDs heterojunctions can be effectively tuned, making them are promising candidates for next-generation electronics.