Van der Waals heterostructures of MoS <sub>2</sub> and Janus MoSSe monolayers on graphitic boron-carbon-nitride ( <i>BC</i> <sub>3</sub> , <i>C</i> <sub>3</sub> <i>N</i> , <i> C <sub>3</sub> N <sub>4</sub> </i> and <i> C <sub>4</sub> N <sub>3</sub> </i> ) nanosheets: a first-principles study
A. Bafekry, M. Yagmurcukardes, Berna Akgenç, Mitra Ghergherehchi, Ch V Nguyen
Abstract
Abstract In this work, we extensively investigate the structural and electronic properties of van der Waals heterostructures (HTs) constructed by MoS 2 / BC 3 , MoS 2 / C 3 N , MoS 2 / <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> , MoS 2 / <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> and those using Janus MoSSe instead of MoS 2 by performing density functional theory calculations. The electronic band structure calculations and the corresponding partial density of states reveal that the significant changes are driven by a quite strong layer–layer interaction between the constitutive layers. Our results show that although all monolayers are semiconductors as free-standing layers, the MoS 2 / C 3 N and MoS 2 / <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> bilayer HTs display metallic behavior as a consequence of the transfer of charge carriers between two constituent layers. In addition, it is found that in the MoSSe/ C 3 N bilayer HT, the degree of metallicity is affected by the interface chalcogen atom type when Se atoms face the C 3 N layer, and the overlap of the bands around the Fermi level is smaller. Moreover, the half-metallic magnetic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> is shown to form a magnetic half-metallic trilayer HT with MoS 2 independent of the stacking sequence, i.e. whether it is sandwiched or a two <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> layer encapsulate MoS 2 layer. We further analyze the trilayer HTs in which MoS 2 is encapsulated by two different monolayers and it is revealed that at least with one magnetic monolayer, it is possible to construct a magnetic trilayer. While the trilayer of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> /MoS 2 / BC 3 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>4</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mi>N</mml:mi> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> </mml:math> /MoS 2 / <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> exhibit half-metallic characteristics, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>C</mml:mi> <m