First-principles prediction of the electronic properties and contact features of graphene/γ-GeSe van der Waals heterostructure: effects of electric fields and strains

In this work, we investigate systematically the electronic properties and tunable contact behavior of the graphene/γ-GeSe heterostructure under applied electric fields and out-of-plane strains using first-principles calculations. At equilibrium, the heterostructure forms a p-type Schottky contact with low Schottky barrier, making it suitable for low-resistance electronic devices. The application of electric fields modulates the Schottky barriers, enabling transitions between p-type and n-type contacts and even Schottky to Ohmic contact. Similarly, strain engineering by adjusting the interlayer spacing effectively alters the contact types, with compressive strain reducing the Schottky barrier to zero, and tensile strain inducing a shift from p-type to n-type Schottky contact. Our findings provide a pathway for optimizing graphene/γ-GeSe heterostructures for multifunctional applications, emphasizing tunable electronic properties to enhance device performance. © 2024 The Royal Society of Chemistry.