Picosecond Electronic and Structural Dynamics in Photoexcited Monolayer MoSe2

ORAL

Abstract

Monolayers of semiconducting transition metal dichalcogenides (TMDC) are emerging as strong candidate materials for next generation electronic and optoelectronic devices. Prior studies have demonstrated strong light-matter interactions in these materials which suggests optical control of material properties is a promising route for their functionalization. However, the electronic and structural dynamics in response to electronic excitation have not yet been fully elucidated. In this work, we use non-adiabatic quantum molecular dynamics based on time-dependent density functional theory to study lattice dynamics of a model TMDC monolayer of MoSe2 after electronic excitation and explore the dependence of dynamics on photo-generated electron-hole density. We observe phonon mode softening induced by Fermi-surface nesting, as well as increasing lattice disorder, as measured by the Debye-Waller factor (DWF), with increasing excitation. Furthermore, we find a transition from single-exponential to bi-exponential decay of the DWF at higher electron-hole densities.

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Presenters

  • Lindsay Bassman

    University of Southern California, Physics, University of Southern California

Authors

  • Lindsay Bassman

    University of Southern California, Physics, University of Southern California

  • Aravind Krishnamoorthy

    Physics & Astronomy, University of Southern California, Univ of Southern California, Physics, University of Southern California, University of Southern California

  • Rajiv Kalia

    Univ of Southern California, Physics & Astronomy, University of Southern California, University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, Univ of Southern California, Collaboratory of Advanced Computing and Simulations, Univ of Southern California, Collaboratory for Advanced Computing and Simulations, University of Southern California, Physics, University of Southern California

  • Aiichiro Nakano

    Univ of Southern California, Physics & Astronomy, University of Southern California, University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, Univ of Southern California, Collaboratory of Advanced Computing and Simulations, Univ of Southern California, Physics, University of Southern California

  • Priya Vashishta

    Univ of Southern California, Physics & Astronomy, University of Southern California, University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, Univ of Southern California, Collaboratory of Advanced Computing and Simulations, Univ of Southern California, Collaboratory for Advanced Computing and Simulations, University of Southern California, Physics, University of Southern California

  • Hiroyuki Kumazoe

    Physics, Kumamoto University, University of Southern California

  • Masaaki Misawa

    Physics, Kumamoto University

  • Fuyuki Shimojo

    Physics, Kumamoto University, Kumamoto University, Department of Physics, Kumamoto University