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dc.contributor.authorVempati S.en_US
dc.contributor.authorCelebioglu A.en_US
dc.contributor.authorUyar T.en_US
dc.date.accessioned2016-02-08T09:33:46Z
dc.date.available2016-02-08T09:33:46Z
dc.date.issued2015en_US
dc.identifier.issn2040-3364
dc.identifier.urihttp://hdl.handle.net/11693/20715
dc.description.abstractIn ref. [Nat. Nanotechnol., 2012, 7, 465-471] interesting optoelectronic properties of ZnO/graphene oxide (GO) composite were presented. Essentially, in the luminescence spectrum indirect optical transitions were identified to be from the epoxy group of GO (GOepoxy) to the valance band (Ev) of ZnO. Viz. 406 nm, L1: (LUMO+2)GO epoxy → Ev and 436 nm, L2: (LUMO)GOepoxy → Ev. Furthermore, the emission peak at ∼550 nm was attributed to zinc interstitials (Znis) or oxygen vacancies (VOs) and shown to span from 350-650 nm (equivalent to a width of ∼0.8 eV). In this report we accentuate two vital though largely ignored concerns as itemized in the following. (i) By considering the growth mechanism of ZnO in the composite, there is a certain possibility that these two bands (L1 and L2) may originate from intrinsic defects of ZnO such as Znis and extended Znis (ex-Znis). Or L1 and L2 might be intrinsic to GO. (ii) The 550 nm emission involves VOs and consists of two components with a typical width of ∼0.3 eV. Here we present the results of a thorough investigation confirming the presence of Znis, ex-Znis and intrinsic emission from GO. We also note that during the synthesis the presence of dimethyl formamide significantly affected the emission from GO in addition to some chemical modifications. Apart from these, we have discussed other crucial factors which require deeper attention in the context of luminescence from complex systems such as those present.en_US
dc.language.isoEnglishen_US
dc.source.titleNanoscaleen_US
dc.relation.isversionofhttp://dx.doi.org/10.1039/c5nr04461hen_US
dc.subjectChemical modificationen_US
dc.subjectDefectsen_US
dc.subjectLuminescenceen_US
dc.subjectOxygen vacanciesen_US
dc.subjectSemiconductor quantum dotsen_US
dc.subjectZinc oxideen_US
dc.subjectDefect-related emissionen_US
dc.subjectGrowth mechanismsen_US
dc.subjectInter-system crossingsen_US
dc.subjectIntrinsic defectsen_US
dc.subjectIntrinsic emissionen_US
dc.subjectLuminescence spectrumen_US
dc.subjectOptoelectronic propertiesen_US
dc.subjectZinc interstitialsen_US
dc.subjectZincen_US
dc.titleDefect related emission versus intersystem crossing: blue emitting ZnO/graphene oxide quantum dotsen_US
dc.typeArticleen_US
dc.departmentInstitute of Materials Science and Nanotechnologyen_US
dc.departmentNanotechnology Research Centeren_US
dc.citation.spage16110en_US
dc.citation.epage16118en_US
dc.citation.volumeNumber7en_US
dc.citation.issueNumber38en_US
dc.identifier.doi10.1039/c5nr04461hen_US
dc.publisherRoyal Society of Chemistryen_US


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