Electrical control of excitons in van der Waals heterostructures with type-II band alignment

A. Chaves, J. G. Azadani, V. Ongun Özçelik, R. Grassi, Tony Low

Research output: Contribution to journalArticle

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Abstract

We investigate excitons in stacked transition-metal dichalcogenide layers under a perpendicularly applied electric field, herein MoSe2/WSe2 van der Waals heterostructures (vdWHs). Band structures are obtained with density functional theory (DFT), along with electron and hole wave functions in conduction and valence bands, respectively. A minimal continuum model, parametrized by the DFT results, is presented, allowing for the calculation of the excitonic states. Although the type-II nature of the heterostructure leads to a fully charge separated interlayer exciton on the ground states, our results show that moderate values of electric field produce more evenly distributed wave functions along the vdWH, namely, hybrid inter/intralayer exciton states, where both the interlayer exciton binding energy and, most notably, its oscillator strength are enhanced.

Original languageEnglish (US)
Article number121302
JournalPhysical Review B
Volume98
Issue number12
DOIs
StatePublished - Sep 12 2018

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Excitons
Heterojunctions
alignment
excitons
Wave functions
Density functional theory
interlayers
Electric fields
wave functions
density functional theory
electric fields
Valence bands
Conduction bands
Binding energy
oscillator strengths
Band structure
Ground state
Transition metals
conduction bands
binding energy

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Electrical control of excitons in van der Waals heterostructures with type-II band alignment. / Chaves, A.; Azadani, J. G.; Özçelik, V. Ongun; Grassi, R.; Low, Tony.

In: Physical Review B, Vol. 98, No. 12, 121302, 12.09.2018.

Research output: Contribution to journalArticle

Chaves, A. ; Azadani, J. G. ; Özçelik, V. Ongun ; Grassi, R. ; Low, Tony. / Electrical control of excitons in van der Waals heterostructures with type-II band alignment. In: Physical Review B. 2018 ; Vol. 98, No. 12.
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