Excitonic effects in the optical properties of 2D materials: An equation of motion approach
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | https://hdl.handle.net/1822/47442 |
Resumo: | We present a unified description of the excitonic properties of four monolayer transition-metal dichalcogenides (TMDC's) using an equation of motion method for deriving the Bethe-Salpeter equation in momentum space. Our method is able to cope with both continuous and tight-binding Hamiltonians, and is less computational demanding than the traditional first-principles approach. We show that the role of the exchange energy is essential to obtain a good description of the binding energy of the excitons. The exchange energy at the $\Gamma-$point is also essential to obtain the correct position of the C-exciton peak. Using our model we obtain a good agreement between the Rydberg series measured for WS$_2$. We discuss how the absorption and the Rydberg series depend on the doping. Choosing $r_0$ and the doping we obtain a good qualitative agreement between the experimental absorption and our calculations for WS$_2$. We also derive a semi-analytical version of Ellitot's formula for TMDC's. |
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Excitonic effects in the optical properties of 2D materials: An equation of motion approachExcitonsTMDBethe-SalpeterDirac2D materialstransition metal dichalcogenidesCiências Naturais::Ciências FísicasScience & TechnologyWe present a unified description of the excitonic properties of four monolayer transition-metal dichalcogenides (TMDC's) using an equation of motion method for deriving the Bethe-Salpeter equation in momentum space. Our method is able to cope with both continuous and tight-binding Hamiltonians, and is less computational demanding than the traditional first-principles approach. We show that the role of the exchange energy is essential to obtain a good description of the binding energy of the excitons. The exchange energy at the $\Gamma-$point is also essential to obtain the correct position of the C-exciton peak. Using our model we obtain a good agreement between the Rydberg series measured for WS$_2$. We discuss how the absorption and the Rydberg series depend on the doping. Choosing $r_0$ and the doping we obtain a good qualitative agreement between the experimental absorption and our calculations for WS$_2$. We also derive a semi-analytical version of Ellitot's formula for TMDC's.A J Chaves acknowledges a scholarship from the Brazilian agency CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico). N M R Peres and R M Ribeiro acknowledge support from the European Commission through the project 'Graphene-Driven Revolutions in ICT and Beyond' (Ref. No.696656), project PTDC/FIS-NAN/3668/2014, and the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Financing UID/FIS/04650/2013. T Frederico thanks for the support of the Brazilian Agencies CNPq and FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo). The authors acknowledge Fanyao Qu and Alan MacDonald for useful discussions about the numerical solution of the homogeneous Bethe-Salpeter equation, and Ermin Malic for sharing with us useful supplementary notes.info:eu-repo/semantics/publishedVersionIOP PublishingUniversidade do MinhoChaves, A. J.Ribeiro, R. M.Frederico, T.Peres, N. M. R.2017-04-042017-04-04T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/1822/47442eng2053-158310.1088/2053-1583/aa6b72info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-05-11T04:50:25Zoai:repositorium.sdum.uminho.pt:1822/47442Portal AgregadorONGhttps://www.rcaap.pt/oai/openairemluisa.alvim@gmail.comopendoar:71602024-05-11T04:50:25Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
title |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
spellingShingle |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach Chaves, A. J. Excitons TMD Bethe-Salpeter Dirac 2D materials transition metal dichalcogenides Ciências Naturais::Ciências Físicas Science & Technology |
title_short |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
title_full |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
title_fullStr |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
title_full_unstemmed |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
title_sort |
Excitonic effects in the optical properties of 2D materials: An equation of motion approach |
author |
Chaves, A. J. |
author_facet |
Chaves, A. J. Ribeiro, R. M. Frederico, T. Peres, N. M. R. |
author_role |
author |
author2 |
Ribeiro, R. M. Frederico, T. Peres, N. M. R. |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Chaves, A. J. Ribeiro, R. M. Frederico, T. Peres, N. M. R. |
dc.subject.por.fl_str_mv |
Excitons TMD Bethe-Salpeter Dirac 2D materials transition metal dichalcogenides Ciências Naturais::Ciências Físicas Science & Technology |
topic |
Excitons TMD Bethe-Salpeter Dirac 2D materials transition metal dichalcogenides Ciências Naturais::Ciências Físicas Science & Technology |
description |
We present a unified description of the excitonic properties of four monolayer transition-metal dichalcogenides (TMDC's) using an equation of motion method for deriving the Bethe-Salpeter equation in momentum space. Our method is able to cope with both continuous and tight-binding Hamiltonians, and is less computational demanding than the traditional first-principles approach. We show that the role of the exchange energy is essential to obtain a good description of the binding energy of the excitons. The exchange energy at the $\Gamma-$point is also essential to obtain the correct position of the C-exciton peak. Using our model we obtain a good agreement between the Rydberg series measured for WS$_2$. We discuss how the absorption and the Rydberg series depend on the doping. Choosing $r_0$ and the doping we obtain a good qualitative agreement between the experimental absorption and our calculations for WS$_2$. We also derive a semi-analytical version of Ellitot's formula for TMDC's. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-04-04 2017-04-04T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://hdl.handle.net/1822/47442 |
url |
https://hdl.handle.net/1822/47442 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
2053-1583 10.1088/2053-1583/aa6b72 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
IOP Publishing |
publisher.none.fl_str_mv |
IOP Publishing |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
mluisa.alvim@gmail.com |
_version_ |
1817544434655428608 |