Controlling the Schottky barrier atMoS2/metal contacts by inserting a BN monolayer

2015/01/09 by Mojtaba Farmanbar, Geert Brocks · 211 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Condensed matter physics #Electron #Fermi level #Graphene research and applications #Layer (electronics) #MXene and MAX Phase Materials #Materials science #Metal #Nanotechnology #Optoelectronics #Physics #Quantum mechanics #Schottky barrier #Schottky diode #Semiconductor #Work function #cond-mat.mtrl-sci

paper · pdf · doi:10.1103/physrevb.91.161304

published in Physical Review B 91(16) (American Physical Society) · 5 pages, 5 figures

arxiv created 2015/01/09 · openalex publication_date 2015/04/17 · arxiv updated 2015/05/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

Making a metal contact to the two-dimensional semiconductor MoS₂ without creating a Schottky barrier is a challenge. Using density functional calculations we show that, although the Schottky barrier for electrons obeys the Schottky-Mott rule for high work function (\ensuremath\gtrsim4.7 eV) metals, the Fermi level is pinned at 0.1--0.3 eV below the conduction band edge of MoS₂ for low work function metals, due to the metal-MoS₂ interaction. Inserting a boron nitride (BN) monolayer between the metal and the MoS₂ disrupts this interaction, and restores the MoS₂ electronic structure. Moreover, a BN layer decreases the metal work function of Co and Ni by \ensuremath∼2 eV, and enables a lineup of the Fermi level with the MoS₂ conduction band. Surface modification by adsorbing a single BN layer is a practical method to attain vanishing Schottky barrier heights.

Citations

• Projector augmented-wave method
• From ultrasoft pseudopotentials to the projector augmented-wave method
• Generalized Gradient Approximation Made Simple
• Van der Waals Density Functional for General Geometries
• Single-layer MoS2 transistors
• Self-interaction correction to density-functional approximations for many-electron systems
• Ab initiomolecular dynamics for liquid metals
• Efficient iterative schemes forab initiototal-energy calculations using a plane-wave basis set

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