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dc.contributor.authorTanoh, Arelo
dc.contributor.authorAlexander-Webber, Jack
dc.contributor.authorXiao, James
dc.contributor.authorDelport, Géraud
dc.contributor.authorWilliams, Cyan
dc.contributor.authorBretscher, Hope
dc.contributor.authorGauriot, Nicolas
dc.contributor.authorAllardice, Jesse
dc.contributor.authorPandya, Raj
dc.contributor.authorFan, Ye
dc.contributor.authorLi, Zhaojun
dc.contributor.authorVignolini, Silvia
dc.contributor.authorStranks, Samuel
dc.contributor.authorHofmann, Stephan
dc.contributor.authorRao, Akshay
dc.date.accessioned2019-08-19T23:31:35Z
dc.date.available2019-08-19T23:31:35Z
dc.date.issued2019-09-11
dc.identifier.issn1530-6984
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/295998
dc.description.abstractMany potential applications of monolayer transition metal dichalcogenides (TMDs) require both high photoluminescence (PL) yield and high electrical mobilities. However, the PL yield of as prepared TMD monolayers is low and believed to be limited by defect sites and uncontrolled doping. This has led to a large effort to develop chemical passivation methods to improve PL and mobilities. The most successful of these treatments is based on the nonoxidizing organic "superacid" bis(trifluoromethane)sulfonimide (TFSI) which has been shown to yield bright monolayers of molybdenum disulfide (MoS2) and tungsten disulfide (WS2) but with trap-limited PL dynamics and no significant improvements in field effect mobilities. Here, using steady-state and time-resolved PL microscopy we demonstrate that treatment of WS2 monolayers with oleic acid (OA) can greatly enhance the PL yield, resulting in bright neutral exciton emission comparable to TFSI treated monolayers. At high excitation densities, the OA treatment allows for bright trion emission, which has not been demonstrated with previous chemical treatments. We show that unlike the TFSI treatment, the OA yields PL dynamics that are largely trap free. In addition, field effect transistors show an increase in mobilities with the OA treatment. These results suggest that OA serves to passivate defect sites in the WS2 monolayers in a manner akin to the passivation of colloidal quantum dots with OA ligands. Our results open up a new pathway to passivate and tune defects in monolayer TMDs using simple "wet" chemistry techniques, allowing for trap-free electronic properties and bright neutral exciton and trion emission.
dc.languageeng
dc.publisherAmerican Chemical Society
dc.rightsAttribution 4.0 International (CC BY)
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/
dc.subjectTungsten disulfide
dc.subjectligand passivation
dc.subjectmobilities
dc.subjectphotoluminescence
dc.titleEnhancing Photoluminescence and Mobilities in WS2 Monolayers with Oleic Acid Ligands.
dc.typeArticle
prism.endingPage6307
prism.issueIdentifier9
prism.publicationDate2019
prism.publicationNameNano Letters: a journal dedicated to nanoscience and nanotechnology
prism.startingPage6299
prism.volume19
dc.identifier.doi10.17863/CAM.43046
dcterms.dateAccepted2019-08-16
rioxxterms.versionofrecord10.1021/acs.nanolett.9b02431
rioxxterms.versionVoR
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.licenseref.startdate2019-09-11
dc.contributor.orcidTanoh, Arelo [0000-0003-2494-5984]
dc.contributor.orcidAlexander-Webber, Jack [0000-0002-9374-7423]
dc.contributor.orcidXiao, James [0000-0002-1713-5599]
dc.contributor.orcidWilliams, Cyan [0000-0002-0218-016X]
dc.contributor.orcidBretscher, Hope [0000-0001-6551-4721]
dc.contributor.orcidAllardice, Jesse [0000-0002-1969-7536]
dc.contributor.orcidPandya, Raj [0000-0003-1108-9322]
dc.contributor.orcidFan, Ye [0000-0003-0998-5881]
dc.contributor.orcidVignolini, Silvia [0000-0003-0664-1418]
dc.contributor.orcidStranks, Samuel [0000-0002-8303-7292]
dc.contributor.orcidHofmann, Stephan [0000-0001-6375-1459]
dc.contributor.orcidRao, Akshay [0000-0003-0320-2962]
dc.identifier.eissn1530-6992
rioxxterms.typeJournal Article/Review
pubs.funder-project-idEngineering and Physical Sciences Research Council (EP/M006360/1)
pubs.funder-project-idEngineering and Physical Sciences Research Council (EP/P027741/1)
pubs.funder-project-idEPSRC (1648003)
pubs.funder-project-idEuropean Research Council (758826)
pubs.funder-project-idEPSRC (1648003)
pubs.funder-project-idEngineering and Physical Sciences Research Council (EP/L016087/1)
pubs.funder-project-idEngineering and Physical Sciences Research Council (EP/L015978/1)
pubs.funder-project-idEngineering and Physical Sciences Research Council (EP/P005152/1)
pubs.funder-project-idEuropean Research Council (756962)
pubs.funder-project-idEPSRC (1948696)
cam.issuedOnline2019-08-16
cam.orpheus.successThu Jan 30 10:40:26 GMT 2020 - Embargo updated
rioxxterms.freetoread.startdate2100-01-01


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Attribution 4.0 International (CC BY)
Except where otherwise noted, this item's licence is described as Attribution 4.0 International (CC BY)