First-principles study of quasiparticle energies and optical excitations of 3C-SiC divacancy

ORAL

Abstract

Using large-scale GW and Bethe-Salpeter equation (BSE) calculations. we investigate the quasiparticle energies and optical absorption spectrum of the divacancy defect in 3C-SiC, a prototypical defect for quantum information applications. Our calculations provide a quantitative prediction of the defect quasiparticle energy levels and zero-phonon absorption line. Interestingly, despite the presence of localized defect states in the gap, we find that the low-energy excitonic states are made primarily of transitions from occupied defect states to continuum conduction states from 3C-SiC, especially from the X point of the Brillouin zone (BZ). The large hybridization between defect states and bulk states in 3C-SiC is different the NV- center in diamond and the divacancy in 4H-SiC, where the deep defect levels are well separated from bulk states. Our study highlights the important role of frontier conduction bands in the optical properties and formation of low-energy excitons in 3C-SiC divacancy.

*We acknowledge support from the Center for Computational Study of Excited-State Phenomena in Energy Materials at the Lawrence Berkeley National Laboratory, which is funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DEAC02-05CH11231.

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Presenters

  • Weiwei Gao

    • Dalian University of Technology

Authors

  • Weiwei Gao

    • Dalian University of Technology

  • Felipe H da Jornada

    • Stanford Univ
    • Stanford University

  • Mauro Del Ben

    • Lawrence Berkeley National Laboratory

  • Jack R Deslippe

    • Lawrence Berkeley National Laboratory

  • Steven G Louie

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • University of California Berkeley
    • University of California, Berkeley
    • University of California at Berkeley; Lawrence Berkeley National Laboratory
    • University of California at Berkeley and Lawrence Berkeley National Laboratory
    • UC berkeley
    • University of California at Berkeley and Lawrence Berkeley National Lab
    • UC Berkeley & Lawrence Berkeley National Laboratory

  • James R Chelikowsky

    • University of Texas at Austin
    • Texas Center for Superconductivity and Department of Chemistry, University of Houston, Houston, TX 77204, USA