Dirac Metallic FeB2 -Induced Low Schottky Barrier and Electrically Tunable Schottky Contact in FeB2/MoS2 van der Waals Heterostructure

Abstract

In this work, we employ first-principles density functional theory (DFT) calculations to systematically investigate the interfacial electronic properties and contact behavior of a Dirac-metallic Dirac-FeB$_2$/MoS$_2$ van der Waals (vdW) heterostructure. The Dirac-FeB$_2$/MoS$_2$ system is found to be energetically, mechanically, thermally, and dynamically stable, indicating its potential experimental feasibility. Notably, the heterostructure forms an n-type Schottky contact with an ultralow electron barrier height of 0.125~eV and a low tunneling resistance of $1.82\times10^{-9}$~$\Omega\cdot$cm$^2$. This superior contact performance is attributed to the delocalized Dirac electrons and the weak Fermi-level pinning at the interface, providing key insight into the role of Dirac metals in contact engineering. Furthermore, the Schottky barrier can be effectively tuned by an external electric field, enabling a reversible transition from Schottky to Ohmic contact. These findings highlight the promise of Dirac metallic FeB$_2$ as an efficient electrode material and offer practical guidance for the design of high-performance 2D nanoelectronic and optoelectronic devices with reduced contact resistance.