Contact Properties of Two-Dimensional Semiconductor As2C3 with Metals and Semimetals

Abstract

The two-dimensional semiconductor As₂C₃, known for its ultrahigh carrier mobility of up to 4.45 × 10⁵ cm² V^–1 s^–1, holds significant potential for next-generation nanoelectronic devices. Selecting the appropriate electrodes is crucial for minimizing contact resistance and enhancing device performance. Using first-principles calculations, we systematically analyze the interface characteristics of As₂C₃ in conjunction with a range of metallic and semimetallic electrodes. Our findings indicate that both As₂C₃/Au and As₂C₃/Bi form efficient Ohmic contacts. At the same time, As₂C₃/graphene exhibits a Schottky contact, where the Schottky barrier height (SBH) can be tuned through external electric fields and vertical strain. Additionally, As₂C₃/NbS₂ and As₂C₃/Sc demonstrate extremely low SBH, classifying them as quasi-Ohmic contacts. Notably, Sc-based contacts facilitate electron tunneling with probabilities reaching up to 100%. Upon contact with Au and Sc, a pronounced Fermi-level pinning (FLP) effect is observed in As₂C₃. These results offer valuable insights for the development and optimization of advanced As₂C₃-based electronic devices.