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dc.contributor.advisorKocabaş, Coşkun
dc.contributor.authorPolat, Emre Ozan
dc.date.accessioned2016-01-08T20:19:54Z
dc.date.available2016-01-08T20:19:54Z
dc.date.issued2015
dc.identifier.urihttp://hdl.handle.net/11693/18504
dc.descriptionAnkara : The Department of Physics and the Graduate School of Engineering and Science of Bilkent University, 2015.en_US
dc.descriptionThesis (Ph. D.) -- Bilkent University, 2015.en_US
dc.descriptionIncludes bibliographical references leaves 86-95.en_US
dc.description.abstractGraphene, a two dimensional crystal of carbon atoms, emerges as a viable material for optoelectronics because of its electrically-tunable broadband optical properties. Optical response of graphene at visible and near infrared frequencies is defined by inter-band electronic transitions. By electrical tuning of the Fermi energy, the inter-band transitions can be blocked due to Pauli blocking. However, controlling inter-band transitions of graphene in the visible and near infrared wavelengths, has been an outstanding challenge. We developed a new device to control optical properties of graphene in the visible spectra. Our device relies on a graphene supercapacitor which includes two parallel graphene electrodes and electrolyte between them. Mutual gating between graphene electrodes enables us to fabricate optical modulators which can operate in the visible and near-infrared. Single layer graphene, however, has performance limits due to its small optical absorption defined by fundamental constants. We extend our method and we developed a new class of electrochromic devices using multilayer graphene. Fabricated devices undergo a reversible color change with the electrically controlled intercalation process. The electrical and optical characterizations of the electrochromic devices reveal the broadband optical modulation up to 55 per cent in the visible and near-infrared. Integration of semiconducting materials on unconventional substrates enables optoelectronic devices with new mechanical functionalities that cannot be achieved with wafer-based technologies. As a novel application, we demonstrate ultra thin electronic paper displays using the multilayer graphene as a reconfigurable optical medium. We anticipate that the developed devices would find wide range of applications in optoelectronics.en_US
dc.description.statementofresponsibilityPolat, Emre Ozanen_US
dc.format.extentxvi, 95 leaves, graphics, illustrationsen_US
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectGrapheneen_US
dc.subjectOptical modulatoren_US
dc.subjectOptoelectronicsen_US
dc.subjectSupercapacitoren_US
dc.subjectSmart windowen_US
dc.subjectElectrochromic devicesen_US
dc.subjectElectrolyteen_US
dc.subject.lccTA455.G65 P65 2015en_US
dc.subject.lcshGraphene.en_US
dc.subject.lcshNanoelectronics.en_US
dc.subject.lcshNanoelectronics--Materials.en_US
dc.titleGraphene based optoelectronics in the visible spectrumen_US
dc.typeThesisen_US
dc.departmentDepartment of Physicsen_US
dc.publisherBilkent Universityen_US
dc.description.degreePh.D.en_US
dc.identifier.itemidB149453
dc.embargo.release2017-01-15


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