The University of Southampton
University of Southampton Institutional Repository

The interplay between excitons and trions in a monolayer of MoSe2

The interplay between excitons and trions in a monolayer of MoSe2
The interplay between excitons and trions in a monolayer of MoSe2
The luminescence and absorption properties of transition metal dichalcogenide monolayers are widely determined by neutral and charged excitonic complexes. Here, we focus on the impact of a free carrier reservoir on the optical properties of excitonic and trionic complexes in a MoSe 2 monolayer at cryogenic temperatures. By applying photodoping via a non-resonant pump laser, the electron density can be controlled in our sample, which is directly reflected in the contribution of excitons and trions to the luminescence signal. We find significant shifts of both the exciton and trion energies in the presence of an induced electron gas both in power- and in time evolution (on the second to minute scale) in our photoluminescence spectra. In particular, in the presence of the photo-doped carrier reservoir, we observe that the splitting between excitons and trions can be enhanced by up to 4 meV. This behaviour is phenomenologically explained by an interplay between an increased screening of excitons via electrons in our system and a modification of the Fermi level. We introduce a simple but still quantitative treatment of these effects within a variational approach that takes into account both screening and phase space filling effects.
0003-6951
Lundt, N.
25b2f169-c96d-4f8f-bff5-a8feab60927d
Cherotchenko, E.
0187efe7-53e5-4844-877b-4662fa1e614a
Iff, O.
296ae26d-7a4d-43b3-adc2-d6edbfd43580
Fan, X.
f3a5292c-245e-4316-81cc-e4d67b5c35f0
Shen, Y.
e3951c80-aa73-4b26-ac3c-ac091051e19a
Bigenwald, P.
92c2e4b5-1fc5-42f0-bd5d-a08bd24061c6
Kavokin, A.V.
70ffda66-cfab-4365-b2db-c15e4fa1116b
Höfling, S.
46f0d11d-1c5a-4de9-a103-16b2686b4dda
Schneider, C.
2537e550-4f1a-43cd-877f-32d60888a673
Lundt, N.
25b2f169-c96d-4f8f-bff5-a8feab60927d
Cherotchenko, E.
0187efe7-53e5-4844-877b-4662fa1e614a
Iff, O.
296ae26d-7a4d-43b3-adc2-d6edbfd43580
Fan, X.
f3a5292c-245e-4316-81cc-e4d67b5c35f0
Shen, Y.
e3951c80-aa73-4b26-ac3c-ac091051e19a
Bigenwald, P.
92c2e4b5-1fc5-42f0-bd5d-a08bd24061c6
Kavokin, A.V.
70ffda66-cfab-4365-b2db-c15e4fa1116b
Höfling, S.
46f0d11d-1c5a-4de9-a103-16b2686b4dda
Schneider, C.
2537e550-4f1a-43cd-877f-32d60888a673

Lundt, N., Cherotchenko, E., Iff, O., Fan, X., Shen, Y., Bigenwald, P., Kavokin, A.V., Höfling, S. and Schneider, C. (2018) The interplay between excitons and trions in a monolayer of MoSe2. Applied Physics Letters, 112 (3), [031107]. (doi:10.1063/1.5019177).

Record type: Article

Abstract

The luminescence and absorption properties of transition metal dichalcogenide monolayers are widely determined by neutral and charged excitonic complexes. Here, we focus on the impact of a free carrier reservoir on the optical properties of excitonic and trionic complexes in a MoSe 2 monolayer at cryogenic temperatures. By applying photodoping via a non-resonant pump laser, the electron density can be controlled in our sample, which is directly reflected in the contribution of excitons and trions to the luminescence signal. We find significant shifts of both the exciton and trion energies in the presence of an induced electron gas both in power- and in time evolution (on the second to minute scale) in our photoluminescence spectra. In particular, in the presence of the photo-doped carrier reservoir, we observe that the splitting between excitons and trions can be enhanced by up to 4 meV. This behaviour is phenomenologically explained by an interplay between an increased screening of excitons via electrons in our system and a modification of the Fermi level. We introduce a simple but still quantitative treatment of these effects within a variational approach that takes into account both screening and phase space filling effects.

Text
The interplay between excitons and trions in a monolayer of MoSe2 - Accepted Manuscript
Download (821kB)

More information

Accepted/In Press date: 11 December 2017
e-pub ahead of print date: 17 January 2018
Published date: January 2018

Identifiers

Local EPrints ID: 418299
URI: http://eprints.soton.ac.uk/id/eprint/418299
ISSN: 0003-6951
PURE UUID: a3827cdf-38e4-41c8-a4c0-c59088c5f7c9

Catalogue record

Date deposited: 27 Feb 2018 17:31
Last modified: 16 Dec 2019 18:26

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×