Effect of spin-orbit interaction on the optical spectra of single-layer, double-layer, and bulk MoS2

Author(s)

Alejandro Molina-Sanchez, Davide Sangalli, Kerstin Hummer, Andrea Marini, Ludger Wirtz

Abstract

We present converged ab initio calculations of the optical absorption spectra of single-layer, double-layer, and bulk MoS2.

Both the quasiparticle-energy calculations (on the level of the GW

approximation ) and the calculation of the absorption spectra (on the

level of the Bethe-Salpeter equation) explicitly include spin-orbit

coupling, using the full spinorial Kohn-Sham wave functions as input.

Without excitonic effects, the absorption spectra would have the form of

a step function, corresponding to the joint density of states of a

parabolic band dispersion in two dimensions. This profile is deformed by

a pronounced bound excitonic peak below the continuum onset. The peak

is split by spin-orbit interaction in the case of single-layer and

(mostly) by interlayer interaction in the case of double-layer and bulk

MoS2.

The resulting absorption spectra are thus very similar in the three

cases, but the interpretation of the spectra is different. Differences

in the spectra can be seen in the shape of the absorption spectra at 3

eV where the spectra of the single and double layers are dominated by a

strongly bound exciton.

Organisation(s)

Computational Materials Physics

External organisation(s)

University of Luxembourg, Université Lille I - Sciences et Technologies, Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", CNR

Journal

Physical Review B

Volume

No. of pages

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.88.045412

Publication date

07-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103009 Solid state physics, 103015 Condensed matter, 103025 Quantum mechanics, 103036 Theoretical physics

Keywords

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