Oxygen Passivation Mediated Tunability of Trion and Excitons in MoS2

Handle URI:
http://hdl.handle.net/10754/625822
Title:
Oxygen Passivation Mediated Tunability of Trion and Excitons in MoS2
Authors:
Gogoi, Pranjal Kumar; Hu, Zhenliang; Wang, Qixing; Carvalho, Alexandra; Schmidt, Daniel; Yin, Xinmao; Chang, Yung-Huang; Li, Lain-Jong ( 0000-0002-4059-7783 ) ; Sow, Chorng Haur; Neto, A. H. Castro; Breese, Mark B. H.; Rusydi, Andrivo; Wee, Andrew T. S.
Abstract:
Using wide spectral range in situ spectroscopic ellipsometry with systematic ultrahigh vacuum annealing and in situ exposure to oxygen, we report the complex dielectric function of MoS2 isolating the environmental effects and revealing the crucial role of unpassivated and passivated sulphur vacancies. The spectral weights of the A (1.92 eV) and B (2.02 eV) exciton peaks in the dielectric function reduce significantly upon annealing, accompanied by spectral weight transfer in a broad energy range. Interestingly, the original spectral weights are recovered upon controlled oxygen exposure. This tunability of the excitonic effects is likely due to passivation and reemergence of the gap states in the band structure during oxygen adsorption and desorption, respectively, as indicated by ab initio density functional theory calculation results. This Letter unravels and emphasizes the important role of adsorbed oxygen in the optical spectra and many-body interactions of MoS2.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Gogoi PK, Hu Z, Wang Q, Carvalho A, Schmidt D, et al. (2017) Oxygen Passivation Mediated Tunability of Trion and Excitons in MoS2. Physical Review Letters 119. Available: http://dx.doi.org/10.1103/PhysRevLett.119.077402.
Publisher:
American Physical Society (APS)
Journal:
Physical Review Letters
Issue Date:
17-Aug-2017
DOI:
10.1103/PhysRevLett.119.077402
Type:
Article
ISSN:
0031-9007; 1079-7114
Sponsors:
This work is supported by ASTAR Pharos Grant No. R-144-000-359-305 and SERC 1527000012, Singapore National Research Foundation under its Competitive Research Funding (NRF-CRP 8-2011-06 and No. R-398-000-087-281), MOE-AcRF Tier-2 (MOE2010-T2-2-121), and FRC (R-144-000-368-112), and the Medium Sized Centre Programme and CRP Grant "Novel 2D materials with tailored properties: Beyond graphene" (R-144-000-295-281). The first-principles calculations were carried out on the Centre for Advanced 2D Materials and Graphene Research Centre high-performance computing facilities.
Additional Links:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.077402
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorGogoi, Pranjal Kumaren
dc.contributor.authorHu, Zhenliangen
dc.contributor.authorWang, Qixingen
dc.contributor.authorCarvalho, Alexandraen
dc.contributor.authorSchmidt, Danielen
dc.contributor.authorYin, Xinmaoen
dc.contributor.authorChang, Yung-Huangen
dc.contributor.authorLi, Lain-Jongen
dc.contributor.authorSow, Chorng Hauren
dc.contributor.authorNeto, A. H. Castroen
dc.contributor.authorBreese, Mark B. H.en
dc.contributor.authorRusydi, Andrivoen
dc.contributor.authorWee, Andrew T. S.en
dc.date.accessioned2017-10-05T12:47:10Z-
dc.date.available2017-10-05T12:47:10Z-
dc.date.issued2017-08-17en
dc.identifier.citationGogoi PK, Hu Z, Wang Q, Carvalho A, Schmidt D, et al. (2017) Oxygen Passivation Mediated Tunability of Trion and Excitons in MoS2. Physical Review Letters 119. Available: http://dx.doi.org/10.1103/PhysRevLett.119.077402.en
dc.identifier.issn0031-9007en
dc.identifier.issn1079-7114en
dc.identifier.doi10.1103/PhysRevLett.119.077402en
dc.identifier.urihttp://hdl.handle.net/10754/625822-
dc.description.abstractUsing wide spectral range in situ spectroscopic ellipsometry with systematic ultrahigh vacuum annealing and in situ exposure to oxygen, we report the complex dielectric function of MoS2 isolating the environmental effects and revealing the crucial role of unpassivated and passivated sulphur vacancies. The spectral weights of the A (1.92 eV) and B (2.02 eV) exciton peaks in the dielectric function reduce significantly upon annealing, accompanied by spectral weight transfer in a broad energy range. Interestingly, the original spectral weights are recovered upon controlled oxygen exposure. This tunability of the excitonic effects is likely due to passivation and reemergence of the gap states in the band structure during oxygen adsorption and desorption, respectively, as indicated by ab initio density functional theory calculation results. This Letter unravels and emphasizes the important role of adsorbed oxygen in the optical spectra and many-body interactions of MoS2.en
dc.description.sponsorshipThis work is supported by ASTAR Pharos Grant No. R-144-000-359-305 and SERC 1527000012, Singapore National Research Foundation under its Competitive Research Funding (NRF-CRP 8-2011-06 and No. R-398-000-087-281), MOE-AcRF Tier-2 (MOE2010-T2-2-121), and FRC (R-144-000-368-112), and the Medium Sized Centre Programme and CRP Grant "Novel 2D materials with tailored properties: Beyond graphene" (R-144-000-295-281). The first-principles calculations were carried out on the Centre for Advanced 2D Materials and Graphene Research Centre high-performance computing facilities.en
dc.publisherAmerican Physical Society (APS)en
dc.relation.urlhttps://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.077402en
dc.rightsArchived with thanks to Physical Review Lettersen
dc.titleOxygen Passivation Mediated Tunability of Trion and Excitons in MoS2en
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalPhysical Review Lettersen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionSingapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore, 117603, , Singaporeen
dc.contributor.institutionDepartment of Physics, Faculty of Science, National University of Singapore, Singapore, 117542, , Singaporeen
dc.contributor.institutionCentre for Advanced 2D Materials, Graphene Research Centre, National University of Singapore, Singapore, 117542, , Singaporeen
dc.contributor.institutionDepartment of Electrophysics, National Chiao Tung University, Hsinchu, 30010, , Taiwanen
dc.contributor.institutionNUSNNI-NanoCore, National University of Singapore, Singapore, 117576, , Singaporeen
kaust.authorLi, Lain-Jongen
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