Bridging Borophene and Metal Surfaces: Structural, Electronic, and Electron Transport Properties

Abstract

Currently, solid interfaces composed of two-dimensional materials (2D) in contact with metal surfaces (m-surf) have been the subject of intense research, where the borophene bilayer (BBL) has been considered a prominent material for the development of electronic devices based on 2D platforms. In this work, we present a theoretical study of the energetic, structural, and electronic properties of the BBL/m-surf interface, with m-surf = Ag, Au, and Al (111) surfaces, and the electronic transport properties of BBL channels connected to the BBL/m-surf top contacts. We find that the bottom-most BBL layer becomes metalized, due to the orbital hybridization with the metal surface states, resulting in BBL/m-surf ohmic contacts, meanwhile, the inner and top-most boron layers kept their semiconducting character. The net charge transfers reveal that BBL has become $n$-type ($p$-type) doped for m-surf = Ag, and Al (= Au). A thorough structural characterization of the BBL/m-surf interface, using a series of simulations of the X-ray photoelectron spectra, shows that the formation of BBL/m-surf interface is characterized by a redshift of the B-$1s$ spectra. Further electronic transport results revealed the emergence of a Schottky barrier between 0.1 and 0.2\,eV between the BBL/m-surf contact and the BBL channels. We believe that our findings are timely, bringing important contributions to the applicability of borophene bilayers for developing 2D electronic devices.

References in corpus (14)

• Electric Field Effect in Atomically Thin Carbon Films
• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Phosphorene: A New 2D Material with High Carrier Mobility
• Density functional method for nonequilibrium electron transport
• Experimental Realization of Two-Dimensional Boron Sheets
• Two-dimensional materials from high-throughput computational exfoliation of experimentally known compounds
• Van der Waals density functional: Self-consistent potential and the nature of the van der Waals bond
• Numerical atomic orbitals for linear scaling
• Novel Precursors for Boron Nanotubes: The Competition of Two-Center and Three-Center Bonding in Boron Sheets
• An exchange functional that tests the robustness of the plasmon description of the van der Waals density functional
• Improvements on non-equilibrium and transport Green function techniques: the next-generation transiesta
• Spin signature of nonlocal-correlation binding in metal organic frameworks
• Broad boron sheets and boron nanotubes: An ab initio study of structural, electronic, and mechanical properties
• Orbital pseudospin-momentum locking in two-dimensional chiral borophene

Cited by in corpus (1)

• Structural dependence of quantum transport properties on topological nodal-line semimetal bilayer borophene