Nano-device Fabrication from Quantum Dot Assembly
Item
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Title
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Nano-device Fabrication from Quantum Dot Assembly
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Identifier
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d_2009_2013:500143fd5597:11528
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identifier
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12024
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Creator
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Su, Wei,
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Contributor
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Hiroshi Matsui
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Date
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2012
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physical chemistry | Nanoscience | Nanotechnology
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Abstract
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Colloidal semiconductor nanocrystals are highly photoluminescent crystalline nanoparticles (also termed as: quantum dots, QDs) with diameters ranging typically from 1 to 10 nm. For over a decade, quantum dots have been applied in various areas ranging from biological imaging, novel sensors to electroluminescence light-emitting diode (LED) due to their unique optical and electrical properties, such as broad excitation region, tunable size-dependant photoluminescence, high quantum yield, excellent chemical stability as compared to conventional organic dyes, and narrow emission peaks.;We successfully designed and built two fluorescence resonant energy transfer (FRET) donor-acceptor assemblies between quantum dots. Each assembly was characterized by steady-state and time-resolved photoluminescence measurements at different donor-to-acceptor ratios. Both photoluminescence quenching and decrease in the lifetime of donor quantum dots provided a concrete evidence of occurrence of FRET in each quantum dots pair assembly. Accompanied by the tunability of the emission energy of quantum dots in the broad visible region, our investigations on QD-QD FRET pairs present an attractive approach towards developing efficient light emitters and bio-sensors. Furthermore, we explored to build a novel microcavity by embedding one QD-QD between two distributed Bragg reflectors (DBRs). The spontaneous emission of QDs embedded inside a quasi one-dimensional microcavity should be further enhanced by FRET from the donor QD to the acceptor of QD.;Bio-templating is a promising alternative method for semiconductor nanowire synthesis since it offers a variety of advantages such as low energy consumption for the synthesis and eases of template bionanotube preparation and CdS coating process. As a continued work, we exploited the direct nucleation and growth of CdS nanocrystals on the biomolecular nanowires without using the mineralization peptides. The whole synthesis process is completed in simple two steps without the uses of catalytic peptides or capping agents, commonly used for various nanoparticle synthesis. We also report a peptide molecule that self-assembles at the air-water interface and is capable of reducing gold ions and coordinating them to form triangular nanoplatelets and related structures. We show that we are able to control both morphology and crystallinity of gold nanoplatelets as a function of surface pressure.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Chemistry
