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dc.contributor.advisorAydınlı, Atillaen_US
dc.contributor.authorAkça, İmranen_US
dc.date.accessioned2016-01-08T18:06:02Z
dc.date.available2016-01-08T18:06:02Z
dc.date.issued2008
dc.identifier.urihttp://hdl.handle.net/11693/14723
dc.descriptionAnkara : The Department of Physics and the Institute of Engineering and Sciences of Bilkent University, 2008.en_US
dc.descriptionThesis (Master's) -- Bilkent University, 2008.en_US
dc.descriptionIncludes bibliographical references leaves 64-70.en_US
dc.description.abstractLow dimensional structures such as quantum dots have been particularly attractive because of their fundamental physical properties and their potential applications in various devices in integrated optics and microelectronics. This thesis presents optical and electrical applications of low dimensional structures. For this purpose we have studied silicon and germanium nanocrystals for flash memory applications and InAs quantum dots for optical modulators. As a quantum dot, nanocrystals can be used as storage media for carriers in flash memories. Performance of a nanocrystal memory device can be expressed in terms of write/erase speed, carrier retention time and cycling durability. Charge and discharge dynamics of PECVD grown nanocrystals were studied. Electron and hole charge and discharge currents were observed to differ significantly and strongly depend on annealing conditions chosen for the formation of nanocrystals. Our experimental results revealed that, discharge currents were dominated by the interface layer acting as a quantum well for holes and route for direct tunneling for electrons. On the other hand, possibility of obtaining quantum dots with enhanced electro-optic and/or electro-absorption coefficients makes them attractive for use in light modulation. Therefore, waveguides of multilayer InAs quantum dots were studied. Electro-optic measurements were conducted at 1.5 µm and clear Fabry-Perot resonances were obtained. The voltage dependent Fabry-Perot measurements revealed that 6 V was sufficient for full on/off modulation. Electroabsorption measurements were conducted at both 1.3 and 1.5 µm. Since the structure lases at 1285 nm, high absorption values at 1309 nm were obtained. The absorption spectrum of the samples was also studied under applied electric field. Absorption spectra of all samples shift to lower photon energies with increasing electric field.en_US
dc.description.statementofresponsibilityAkça, İmranen_US
dc.format.extentxv, 70 leaves, graphsen_US
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectSilicon nanocrystalsen_US
dc.subjectoptical waveguidesen_US
dc.subjectelectro-absorption modulationen_US
dc.subjectelectro-optic modulationen_US
dc.subjectquantum dotsen_US
dc.subjectnonvolatile memoriesen_US
dc.subjectGermanium nanocrystalsen_US
dc.subject.lccQC611.8.N33 A53 2008en_US
dc.subject.lcshNanocrystals--Optical properties.en_US
dc.subject.lcshNanocrystals--Electrical properties.en_US
dc.subject.lcshLow-dimensional semiconductors.en_US
dc.subject.lcshSilicon crystals.en_US
dc.subject.lcshGermanium.en_US
dc.subject.lcshElectronic structure.en_US
dc.titleLow dimensional structures for optical and electrical applicationsen_US
dc.typeThesisen_US
dc.departmentDepartment of Physicsen_US
dc.publisherBilkent Universityen_US
dc.description.degreeM.S.en_US


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