Strain, electric-field and functionalization induced widely tunable electronic properties in MoS <sub>2</sub> / <i>BC</i> <sub>3</sub> , / <i>C</i> <sub>3</sub> <i>N</i> and / <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:math> van der Waals heterostructures
A. Bafekry, Catherine Stampfl, Mitra Ghergherehchi
Abstract
Abstract In this paper, the effect of BC 3 , C 3 N and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:math> substrates on the atomic and electronic properties of MoS 2 were systematically investigated using first-principles calculations. Our results show that the MoS 2 / BC 3 and MoS 2 / C 3 N 4 heterostructures are direct semiconductors with band gaps of 0.4 and 1.74 eV, respectively, while MoS 2 / C 3 N is a metal. Furthermore, the influence of strain and electric field on the electronic structure of these van der Waals heterostructures is investigated. The MoS 2 /BC 3 heterostructure, for strains larger than −4%, transforms it into a metal where the metallic character is maintained for strains larger than −6%. The band gap decreases with increasing strain to 0.35 eV (at +2%), while for strain (>+6%) a direct-indirect band gap transition is predicted to occur. For the MoS 2 /C 3 N heterostructure, the metallic character persists for all strains considered. On applying an electric field, the electronic properties of MoS 2 /C 3 N 4 are modified and its band gap decreases as the electric field increases. Interestingly, the band gap reaches 30 meV at +0.8 V/Å, and with increase above +0.8 V/Å, a semiconductor-to-metal transition occurs. Furthermore, we investigated effects of semi- and full-hydrogenation of MoS 2 /C 3 N and we found that it leads to a metallic and semiconducting character, respectively.