Two-dimensional TaS2 as a contact material for MXene Sc2CF2 semiconductors: a first-principles study

Abstract

Metal–semiconductor heterojunctions are fundamental to modern electronics, serving as the key interface for charge transport and enabling diverse functionalities in electronic and optoelectronic devices. In this work, we computationally design the electrical contact architecture by vertically integrating two-dimensional TaS₂ and Sc₂CF₂ materials using first-principles predictions. The TaS₂/Sc₂CF₂ heterostructure is predicted to be energetically and thermally stable at room temperature and characterized by weak van der Waals interactions. Additionally, the integration of TaS₂ with Sc₂CF₂ enhances the mechanical rigidity of the heterostructure. More interestingly, the TaS₂/Sc₂CF₂ heterostructure forms a Schottky contact with an electron barrier of 0.36 eV. Furthermore, it exhibits remarkable tunability in electronic properties and contact behavior under an applied electric field. Specifically, the electric field induces a transition from Schottky to ohmic contact, as well as a conversion from n-type to p-type Schottky contact. This tunability signifies a barrier-free charge injection process, making the TaS₂/Sc₂CF₂ heterostructure a promising candidate for next-generation electronic and optoelectronic devices.