Interfacial characteristics, metal-semiconductor contact and optical properties of CSe and BX (X=B, As and Sb) monolayers

Abstract

Two dimensional (2D) materials with large family recently drawn tremendous attention due to their versatile applications. Appreciating the smooth surface and atomic thickness of 2D materials, which can be constructed in the form of heterostructures, resulting interesting chemical and physical properties in many fields. Particularly, 2D metal-semiconductor contact (MS contact), shown great promise in nanodevices and optoelectronic devices application. In this work, we have constructed the MS contact of CSe and BX (X = P, As and Sb) monolayers and investigated the interfacial characteristics, Schottky contact and optical properties, using density functional theory. Our calculated binding energies and thermal stability confirm that CSe-BX (X = P, As and Sb) MS contact are dynamically and thermally stable. Our prediction shows that CSe-BX (X = P, As and Sb) MS contact forms n-type contact, while well preserved the properties of both monolayers. A small band gap opening in CSe having high carrier mobilities, indicated that CSe-BX (X = P, As and Sb) MS contact are good candidates for high speed nanoelectronics applications. Electrostatic potential and Bader charge analysis confirm that electrons are transfer from CSe layer to the BS monolayers and the potential drops separates charge carrier at the interface, play crucial rule in power conversion efficiency. The imaginary part shows an intense absorption peak near the visible region, hence shows appalling application in photoelectronic and optical transmissions.