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Binding energies of exciton complexes in transition metal dichalcogenide monolayers and effect of dielectric environment

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Details

Original languageEnglish
Article number205418
Number of pages6
JournalPhysical Review B
Volume92
Issue number20
DOIs
Publication statusPublished - 16 Nov 2015
Publication typeA1 Journal article-refereed

Abstract

Excitons, trions, biexcitons, and exciton-trion complexes in two-dimensional transition metal dichalcogenide sheets of MoS2, MoSe2, MoTe2, WS2, and WSe2 are studied by means of density functional theory and pathintegral Monte Carlo method in order to accurately account for the particle-particle correlations. In addition, the effect of dielectric environment on the properties of these exciton complexes is studied by modifying the effective interaction potential between particles. Calculated exciton and trion binding energies are consistent with previous experimental and computational studies, and larger systems such as biexciton and exciton-trion complex are found highly stable. Binding energies of biexcitons are similar to or higher than those of trions, but the binding energy of the trion depends significantly stronger on the dielectric environment than that of biexciton. Therefore, as a function of an increasing dielectric constant of the environment the exciton-trion complex "dissociates" to a biexciton rather than to an exciton and a trion.

Keywords

  • SINGLE-LAYER MOS2, SEMICONDUCTOR, TRIONS, STATES, WSE2, BIEXCITONS, WS2

Publication forum classification

Field of science, Statistics Finland