Interlayer excitons in MoSe2/WSe2 heterostructures from first principles

Journal article


Publication Details

Author(s): Gillen R, Maultzsch J
Journal: Physical Review B
Publisher: AMER PHYSICAL SOC
Publication year: 2018
Volume: 97
Journal issue: 16
ISSN: 2469-9950
Language: English


Abstract

Based on ab initio theoretical calculations of the optical spectra of vertical heterostructures of MoSe2 (or MoS2) and WSe2 sheets, we reveal two spin-orbit-split Rydberg series of excitonic states below the A excitons of MoSe2 and WSe2 with a significant binding energy on the order of 250 meV for the first excitons in the series. At the same time, we predict from accurate many-body G(0)W(0) calculations that crystallographically aligned MoSe2/WSe2 heterostructures exhibit an indirect fundamental band gap. Due to the type-II nature of the MoSe2/WSe2 heterostructure, the indirect transition and the exciton Rydberg series corresponding to a direct transition exhibit a distinct interlayer nature with spatial charge separation of the coupled electrons and holes. Our calculations confirm the recent experimental observation of a doublet nature of the long-lived states in photoluminescence spectra of MoX2/WY2 heterostructures, and we attribute these two contributions to momentum-direct interlayer excitons at the K point of the hexagonal Brillouin zone and to momentum-indirect excitons at the indirect fundamental band gap. Our calculations further suggest a noticeable effect of stacking order on the electronic band gaps and on the peak energies of the interlayer excitons and their oscillation strengths.


FAU Authors / FAU Editors

Gillen, Roland
Lehrstuhl für Experimentalphysik
Maultzsch, Janina Prof. Dr.
Lehrstuhl für Experimentalphysik


Research Fields

Layered materials
Lehrstuhl für Experimentalphysik


How to cite

APA:
Gillen, R., & Maultzsch, J. (2018). Interlayer excitons in MoSe2/WSe2 heterostructures from first principles. Physical Review B, 97(16). https://dx.doi.org/10.1103/PhysRevB.97.165306

MLA:
Gillen, Roland, and Janina Maultzsch. "Interlayer excitons in MoSe2/WSe2 heterostructures from first principles." Physical Review B 97.16 (2018).

BibTeX: 

Last updated on 2019-18-03 at 10:03