Year: 2015
Type: article
Abstract: We address the properties of excitons in monolayer ${\mathrm{MoS}}_{2}$ from a theoretical point of view, showing that low-energy excitonic states occur both at the Brillouin-zone center and at the Brillouin-zone corners, that binding energies at the Brillouin-zone center deviate strongly from the ${(n\ensuremath{-}1/2)}^{\ensuremath{-}2}$ pattern of the two-dimensional hydrogenic model, and that the valley-degenerate exciton doublet at the Brillouin-zone center splits at finite momentum into an upper mode with nonanalytic linear dispersion and a lower mode with quadratic dispersion. Although monolayer ${\mathrm{MoS}}_{2}$ is a direct-gap semiconductor when classified by its quasiparticle band structure, it may well be an indirect gap material when classified by its excitation spectra.
Source: Physical Review B
Authors: Fengcheng Wu, Fanyao Qu, A. H. MacDonald
Institutions: The University of Texas at Austin, Universidade de Brasília
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2073029842