Selective plasmonic control of excitons and their non-radiative energy transfer in colloidal semiconductor quantum dot solids

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buir.advisorDemir, Hilmi Volkan
dc.contributor.authorÖzel, Tuncay
dc.date.accessioned2016-01-08T18:21:11Z
dc.date.available2016-01-08T18:21:11Z
dc.date.issued2009
dc.departmentDepartment of Physicsen_US
dc.descriptionAnkara : The Department of Physics and the Institute of Engineering and Sciences of Bilkent University, 2009.en_US
dc.descriptionThesis (Master's) -- Bilkent University, 2009.en_US
dc.descriptionIncludes bibliographical references leaves 70-76.en_US
dc.description.abstractTo date extensive research has proved that semiconductors and metals exhibit extraordinary optical properties in nano-dimensions compared to their bulk counterparts. For example, an interesting effect is observed in metal nanostructures/nanoparticles (NPs) that we form to obtain localized plasmons, with their optical response highly tuneable using the size effect. Another field of interest at the nanoscale is the investigation of light generation and harvesting using colloidal semiconductor quantum dot nanocrystals (NCs) that we synthesize in few nanometers, with their emission and absorption excitonic peaks conveniently tuneable using the size effect. In this thesis, we proposed and demonstrated the first accounts of selectively plasmonically-controlled colloidal quantum dot emitters assembled in innovative architectures, with a control achieved either through spatial selection or spectral selection. In the first set of designs, we developed for the first time plasmonic NC-composites that rely on spatially-selected plasmon-coupled CdTe NC-monolayers interspaced with respect to Au NP-monolayers in a repeating three-dimensional layer-by-layer architecture. In these bottom-up designs of hybrid nanocomposites, the photoluminescence kinetics is strongly modified and a record quantum efficiency of 30% is achieved for such CdTe NC solids. In the second set of designs, we showed the first spectrally-selected plasmon-coupling of surfaceemitting CdS NCs using optimized Ag NP deposits. This architecture allowed for the surface-state emission to be selectively enhanced while the interband emission is simultaneously suppressed in the same plasmon-coupled NCs, leading to the strongest surface-state emission from such CdS NCs reported with respect to their interband emission (with a >12-fold enhancement). Yet another important proximity phenomenon effective among quantum dot emitters is the Förster-type non-radiative resonance energy transfer (ET), in which excitonic excitation energy of the donor-NCs is non-radiatively transferred to the acceptor-NCs via dipole-dipole coupling. In the third set of our designs, we combined two fundamental proximity mechanisms of plasmon coupling and non-radiative energy transfer in the same NC solids. In plasmonic ET, we reported for the first time selectively plasmon-coupling of NC-acceptors and then that of NC-donors in the ET pair, both of which result in substantial enhancement of the acceptor emission with respect to ET with no plasmon coupling (with a maximum of 2-fold enhancement) as verified by their steadystate and time-resolved photoluminescence. This concept of spectrally/spatiallyselective plasmon coupling in quantum dots paves a new path for devices and sensors in nanophotonics.en_US
dc.description.degreeM.S.en_US
dc.description.statementofresponsibilityÖzel, Tuncayen_US
dc.format.extentxv, 76 leaves, illustrationsen_US
dc.identifier.urihttp://hdl.handle.net/11693/15593
dc.language.isoEnglishen_US
dc.publisherBilkent Universityen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectPlasmonicsen_US
dc.subjectlocalized plasmonsen_US
dc.subjectmetal nanoparticlesen_US
dc.subjectmetal nanostructuresen_US
dc.subjectnon-radiative Förster energy transferen_US
dc.subjectsemiconductor nanocrystalsen_US
dc.subjectcolloidal quantum dotsen_US
dc.subjectexcitonsen_US
dc.subjectspontaneous emissionen_US
dc.subjectphotoluminescenceen_US
dc.subjectmetal-enhanced luminescenceen_US
dc.subjectFDTDen_US
dc.subject.lccQC611.6.O6 O94 2009en_US
dc.subject.lcshSemiconductors--Optical properties.en_US
dc.subject.lcshQuantum electronics.en_US
dc.subject.lcshQuantum dots.en_US
dc.subject.lcshPlasmons (Physics)en_US
dc.subject.lcshNanostructures--Optical properties.en_US
dc.titleSelective plasmonic control of excitons and their non-radiative energy transfer in colloidal semiconductor quantum dot solidsen_US
dc.typeThesisen_US

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Dept. of Physics - Master's degree