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Controlled dynamic screening of excitonic complexes in 2D semiconductors.

ABSTRACT: We report a combined theoretical/experimental study of dynamic screening of excitons in media with frequency-dependent dielectric functions. We develop an analytical model showing that interparticle interactions in an exciton are screened in the range of frequencies from zero to the characteristic binding energy depending on the symmetries and transition energies of that exciton. The problem of the dynamic screening is then reduced to simply solving the Schrodinger equation with an effectively frequency-independent potential. Quantitative predictions of the model are experimentally verified using a test system: neutral, charged and defect-bound excitons in two-dimensional monolayer WS2, screened by metallic, liquid, and semiconducting environments. The screening-induced shifts of the excitonic peaks in photoluminescence spectra are in good agreement with our model.

SUBMITTER: Klots AR

PROVIDER: S-EPMC5768700 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

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Controlled dynamic screening of excitonic complexes in 2D semiconductors.

Klots Andrey R AR Weintrub Benjamin B Prasai Dhiraj D Kidd Daniel D Varga Kalman K Velizhanin Kirill A KA Bolotin Kirill I KI

Scientific reports 20180115 1

We report a combined theoretical/experimental study of dynamic screening of excitons in media with frequency-dependent dielectric functions. We develop an analytical model showing that interparticle interactions in an exciton are screened in the range of frequencies from zero to the characteristic binding energy depending on the symmetries and transition energies of that exciton. The problem of the dynamic screening is then reduced to simply solving the Schrodinger equation with an effectively f ...[more]

PMID: 29335642

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