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Diffusion quantum Monte Carlo study of excitonic complexes in two-dimensional transition-metal dichalcogenides

Published version
Peer-reviewed

Type

Article

Change log

Authors

Szyniszewski, M 
Price, CH 
Maezono, R 
Danovich, M 

Abstract

Excitonic effects play a particularly important role in the optoelectronic behavior of two-dimensional semiconductors. To facilitate the interpretation of experimental photoabsorption and photoluminescence spectra we provide (i) statistically exact diffusion quantum Monte Carlo binding-energy data for a Mott-Wannier model of (donor/acceptor-bound) excitons, trions, and biexcitons in two-dimensional semiconductors in which charges interact via the Keldysh potential, (ii) contact pair-distribution functions to allow a perturbative description of contact interactions between charge carriers, and (iii) an analysis and classification of the different types of bright trions and biexcitons that can be seen in single-layer molybdenum and tungsten dichalcogenides. We investigate the stability of biexcitons in which two charge carriers are indistinguishable, finding that they are only bound when the indistinguishable particles are several times heavier than the distinguishable ones. Donor/acceptor-bound biexcitons have similar binding energies to the experimentally measured biexciton binding energies. We predict the relative positions of all stable free and bound excitonic complexes of distinguishable charge carriers in the photoluminescence spectra of WSe2 and MoSe2.

Description

Keywords

cond-mat.mes-hall, cond-mat.mes-hall

Journal Title

Physical Review B - Condensed Matter and Materials Physics

Conference Name

Journal ISSN

2469-9950
2469-9969

Volume Title

96

Publisher

American Physical Society
Sponsorship
European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (696656)