Achieving Ohmic Contacts in NbS2/MoSe2 van der Waals Heterostructure: A First-Principles Study

The functionality of electronic and optoelectronic devices relying on two-dimensional (2D) materials can be substantially influenced by the characteristics of their electrical contacts. Herein, a metal–semiconductor electrical contact between metallic NbS2 and semiconducting MoSe2 monolayer is constructed using first-principles calculations. The electronic properties and contact characteristics of the NbS2/MoSe2 heterostructure as well as the effects of electric fields and in-plane strains are also explored. These results indicate that the NbS2/MoSe2 heterostructure exhibits the p-type Schottky contact (ShC) with low Schottky barriers and possesses low contact resistance of the tunneling barrier. Furthermore, the electronic properties and contact characteristics of the NbS2/MoSe2 heterostructure can be fine-tuned through the application of in-plane strains and electric fields. The electric fields give rise to the transformation from p-type to n-type ShC as well as the conversion from ShC to Ohmic contact (OhC) in the NbS2/MoSe2 heterostructure. Similarly, in-plane strains play a role in direct-to-indirect band gap transitions and further contribute to the conversion from ShC to OhC in the NbS2/MoSe2 heterostructure. These findings offer valuable theoretical insights that can guide the practical utilization of the NbS2/MoSe2 vdW-MSH in the development of next-generation electronic and optoelectronic devices. © 2023 Wiley-VCH GmbH.