DGIST Scholar: Optical Absorption of Armchair MoS2 Nanoribbons: Enhanced Correlation Effects in the Reduced Dimension

Title: Optical Absorption of Armchair MoS2 Nanoribbons: Enhanced Correlation Effects in the Reduced Dimension

Citation: Kim, Jongmin. (2015-06). Optical Absorption of Armchair MoS2 Nanoribbons: Enhanced Correlation Effects in the Reduced Dimension. Journal of Physical Chemistry C, 119(24), 13901–13906. doi: 10.1021/acs.jpcc.5b02232

Keywords: Approximation Algorithms ; Bethe-Salpeter Equation ; Binding Energy ; Calculations ; Correlation Detectors ; Correlation Effect ; ELECTRIC-FIELD ; Electromagnetic Wave Absorption ; EXCITATIONS ; Excitons ; First-Principles Calculation ; GRAPHENE NANORIBBONS ; Light Absorption ; Magnetism ; Molybdenum Compounds ; MONOLAYER MOS2 ; Nanoribbons ; Optical Correlation ; Optical Materials ; Perturbation Techniques ; Perturbation Theory ; PHOTOLUMINESCENCE ; Quasi Particles ; Random Phase Approximations ; Reduced-Dimensional ; SINGLE-LAYER MOS2 ; Single Layer ; SPECTRA ; Unmanned Aerial Vehicles (UAV) ; VALLEY POLARIZATION ; Wave Functions

Abstract: We carry out first-principles calculations of the quasi-particle band structure and optical absorption spectra of H-passivated armchair MoS2 nanoribbons (AMoS2NRs) by employing the approach combining the Green's function perturbation theory (GW) and the Bethe-Salpeter equation (BSE), i.e., GW+BSE. Optical absorption spectra of AMoS2NRs show the exciton multibands (their binding energies are close to or less than 1 eV) which are much stronger than a single layer of MoS2. However, they are absent in the spectra by the approach of GW and the random phase approximation (RPA), i.e., GW+RPA. This signifies that the excitonic correlation effects are strongly enhanced in the reduced dimensional structure of MoS2. We also calculate the exciton wave functions for the few lowest energy excitons, which are found to have non-Frenkel character. © 2015 American Chemical Society.

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