Exciton-phonon dephasing and linewidth from first-principles in monolayer MoS<sub>2</sub>

ORAL

Abstract



Exciton-phonon interactions dominate the temperature dependence of the absorption and luminescence spectrum and determines exciton transfer rates (on fs to ps time scales) in many materials. However, the direct experimental measurement of exciton-phonon interaction is challenging and often subjects to interpretation based on parameterized model Hamiltonians. We apply here a first-principles approach to study exciton-phonon coupling in monolayer MoS2 and shows the highly selective nature of exciton-phonon coupling due to the internal spin structure of excitons, which leads to a surprisingly long lifetime of the lowest energy bright A exciton. Moreover, we show that interference terms due to off-diagonal exciton-phonon matrix elements, which have thus far been neglected in first-principles studies, are critical for the description of dephasing mechanisms, and once accounted for, yield exciton linewidths in excellent agreement with experiment.

*This work was supported by the Center for Computational Study of Excited State Phenomena in Energy Materials (C2SEPEM), which is funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-05CH11231. Y.H.C. acknowledges support by the Ministry of Science and Technology, National Center for Theoretical Sciences (Grant No. 110-2124-M-002-012 and 110-2112-M-001-018 -MY3).

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Presenters

  • Yang-hao Chan

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory; University of California at Berkeley; Institute of Atomic and Molecular Sciences, Academia Sinica

Authors

  • Yang-hao Chan

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory; University of California at Berkeley; Institute of Atomic and Molecular Sciences, Academia Sinica

  • Jonah B Haber

    • University of California, Berkeley
    • University of California, Berkeley; Lawrence Berkeley National Laboratory
    • Department of Physics, University of California, Berkeley
    • Department of Physics, University of California, Berkeley, CA 94720; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.

  • Mit H Naik

    • University of California, Berkeley
    • University of California at Berkeley and Lawrence Berkeley National Laboratory
    • University of California at Berkeley and Lawrence Berkeley National Lab

  • Jeffrey B Neaton

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley; Lawrence Berkeley National Laboratory; Kavli Energy NanoSciences Institute at Berkeley
    • Department of Physics, University of California, Berkeley; Materials Sciences Division, Lawrence Berkeley National Laboratory; Kavli Energy NanoScience Institute at Berkeley
    • Department of Physics, University of California, Berkeley, CA 94720; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Kavli Energy Nano

  • Diana Y Qiu

    • Yale University

  • Felipe H da Jornada

    • Stanford Univ
    • Stanford University

  • 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