Substrate Renormalization of Quasiparticle Band Gaps and Exciton Binding Energies in Quasi-2D Materials

ORAL

Abstract

Atomically thin quasi-two-dimensional (quasi-2D) materials, such as monolayer transition-metal dichalcogenides, display a much weaker electronic screening compared to their bulk counterparts as well as restricted geometry for the motion of the electrons. As a result, electron-electron and electron-hole interactions are enhanced. Owing to the atomic dimension of layer thickness, quasi-2D materials are sensitive to the screening environment produced by substrates, which allows one to dramatically tune their quasiparticle and optical properties. In this work, we extend a method recently developed in our group to incorporate substrate screening into the calculation of quasiparticle and optical properties of quasi-2D materials. We perform full-frequency ab initio GW and GW-Bethe Salpeter equation (GW-BSE) calculations to quantify the effect of the substrate on the electronic and optical gaps of quasi-2D systems. We find that a careful treatment of the dynamical effects of substrate polarizability is necessary to explain the effect of the renormalization on metallic substrates.

*This work was supported by NSF Grant No. DMR-1508412 and the DOE under Contract No. DE-AC02-05CH11231. Computational resources have been provided by DOE at Lawrence Berkeley National Laboratory's NERSC facility.

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Presenters

  • Chin Shen Ong

    • Physics, Univ of California - Berkeley

Authors

  • Chin Shen Ong

    • Physics, Univ of California - Berkeley

  • Felipe da Jornada

    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Physics, Univ of California - Berkeley
    • UC Berkeley and Lawrence Berkeley National Lab

  • Diana Qiu

    • Physics, University of California, Berkeley
    • Physics, Univ of California - Berkeley
    • Lawrence Berkeley National Lab and University of California - Berkeley

  • Steven Louie

    • Physics, University of California, Berkeley
    • University of California, Berkeley
    • Physics, Univ of California - Berkeley
    • Univ of California - Berkeley
    • Physics, UC Berkeley
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Department of Physics, University of California, Berkeley
    • Physics Department, University of California Berkeley and Lawrence Berkeley National Lab
    • Department of physics, University of California - Berkeley
    • Lawrence Berkeley National Lab and University of California - Berkeley
    • Materials Sciences Division, Lawrence Berkeley National Laboratory & Department of Physics, University of California at Berkeley
    • UC Berkeley and Lawrence Berkeley National Lab
    • Physics, University of California - Berkeley