Tunable contact properties in Cu2Te/metals via graphene interlayer

Abstract

The contact properties between two-dimensional (2D) channel materials and electrodes critically govern the overall performance of nanodevices. Recently fabricated semiconducting Cu₂Te monolayer with high carrier mobility and exceptional environmental stability is a promising channel material for high-performance nanodevices. Herein, the contact properties of Cu₂Te with various metals (Mo, W, Sb, Cu, and Ni) and the role of graphene interlayer in tailoring these interfaces are systematically investigated based on first-principles calculations. First-principles calculations reveal that, by intercalating graphene layers, the strong interactions between Cu₂Te and metallic electrodes (Mo, W, Cu, and Ni) are weakened, enabling tunable contact types via work function engineering. The n-type Ohmic contacts at Cu₂Te/Mo, Cu₂Te/W, and Cu₂Te/Cu interfaces transition to p-type behavior as the number of graphene layers increases, whereas Cu₂Te/Ni interfaces exhibit no contact-type switching. By decoupling Cu₂Te/metals, such graphene interlayers can suppress FLP and tailor contact types, which are beneficial for reconfigurable nanodevices. This work provides valuable theoretical insights for the development of high-performance Cu₂Te-based nanodevices.