Electronic properties of bilayer mixtures of WS2 and MoS2 with different stackings

ORAL

Abstract

Besides graphene and hexagonal boron nitride, transition metal chalcogenides (TMC) such as MoS2, WS2, NbS2 and WSe2 also exhibit a layered structure in which the layers weakly interact via Van der Waals forces, and for this reason these materials exhibit excellent lubrication properties. For TMC, the layers are formed by the transition metal atom sandwiched by the sulfur atoms. MoS2 and WS2 in bulk are indirect band gap semiconducting materials. However, an isolated sheet of MoS2 or WS2 becomes a direct gap semiconductor. This particular behavior makes them very attractive in terms of optical properties such as spin polarization, in which the lack of center of inversion of one layer plays a crucial role. Therefore, it is important to study the properties of different configurations of WS2 and MoS2 mixtures bi-layer TMC systems with different stackings. First principles calculations are carried out to study how the indirect and the direct gaps behave, thus shedding light in a new type of bi-layered material.

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Authors

  • Humberto Terrones

    The Pennsylvania State University, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory

  • Ana L. El\'Ias

    Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA, The Pennsylvania State University, Penn State University, University Park, PA, Penn State University, Department of Physics, The Pennsylvania State University

  • Nestor Perea-Lopez

    Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA, The Pennsylvania State University, Pennsylvania State University, Department of Physics, The Pennsylvania State University

  • Humberto R. Gutierrez

    Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 USA., University of Louisville, Department of Physics and Astronomy, University of Louisville, KY

  • Ayse Berkdemir

    Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA, The Pennsylvania State University, Department of Physics, The Pennsylvania State University

  • Andres Castro-Beltran

    Universidad Autonoma de Nuevo Leon, The Pennsylvania State University

  • Ruitao Lv

    Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA, The Pennsylvania State University

  • Florentino Lopez-Urias

    The Pennsylvania State University, The Pennsylvania State University, IPICYT

  • Takuya Hayashi

    Shinshu University

  • Yoong Ahm Kim

    Shinshu University

  • Morinobu Endo

    Shinshu University

  • Mauricio Terrones

    The Pennsylvania State University, Pennsylvania State University, Department of Physics, The Pennsylvania State University