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Theses/Dissertations

Quantum Dots

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Full-Text Articles in Nanoscience and Nanotechnology

Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, Ramesh Vasan May 2018

Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, Ramesh Vasan

Theses and Dissertations

Quantum dot light emitting diodes are investigated as a replacement to the existing organic light emitting diodes that are commonly used for thin film lighting and display applications. In this, all-inorganic quantum dot light emitting diodes with inorganic quantum dot emissive layer and inorganic charge transport layers are designed, fabricated, and characterized. Inorganic materials are more environmentally stable and can handle higher current densities than organic materials. The device consists of CdSe/ZnS alloyed core/shell quantum dots as the emissive layer and metal oxide charge transport layer. The charge transport in these devices is found to occur through resonant ...


Immunostimulatory Effects Of Antigen-Conjugated Inp/Zns Quantum Dot Nanoparticles In An Avian Model, Christopher Lyle May 2018

Immunostimulatory Effects Of Antigen-Conjugated Inp/Zns Quantum Dot Nanoparticles In An Avian Model, Christopher Lyle

Theses and Dissertations

Due to their unique physicochemical and enhanced immunostimulatory properties, quantum dot (QD) nanoparticles have shown increasing promise in biomedical research applications including bioimaging, drug delivery, and as vaccine adjuvants. Toxicity, however, remains a concern for the use of QD in these applications and thus, there is an increased demand for effective in vitro and in vivo systems to measure the bioactivity of QD. In this study in vitro and in vivo chicken models were used to investigate the effects of QD on innate and adaptive immunity. Chicken macrophage cultures were treated in vitro with QD to measure macrophage activation and ...


From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson Apr 2018

From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson

Nanoscience and Microsystems ETDs

Semiconducting nanocrystals, also known as quantum dots (QDs), that emit light with near-unity quantum yield and are extremely photostable are attractive options as down-conversion and direct electricity-to-light materials for a variety of applications including solid-state lighting, display technologies, bio-imaging and optical tracking. Standard QDs with a core/thin shell structure display fluorescence intermittency (blinking) and photobleaching when exposed to prolonged room temperature excitation for single dot measurements, as well as significant reabsorption and energy transfer when densely packed into polymers or at high solution concentrations.

We have developed thick shell “giant” QDs (gQDs), ultra-stable photon sources both at the ensemble ...


The Dawn Of New Quantum Dots: Synthesis And Characterization Of Ge1-Xsnx Nanocrystals For Tunable Bandgaps., Richard J. Esteves Jan 2016

The Dawn Of New Quantum Dots: Synthesis And Characterization Of Ge1-Xsnx Nanocrystals For Tunable Bandgaps., Richard J. Esteves

Theses and Dissertations

Ge1-xSnx alloys are among a small class of benign semiconductors with composition tunable bandgaps in the near-infrared spectrum. As the amount of Sn is increased the band energy decreases and a transition from indirect to direct band structure occurs. Hence, they are prime candidates for fabrication of Si-compatible electronic and photonic devices, field effect transistors, and novel charge storage device applications. Success has been achieved with the growth of Ge1-xSnx thin film alloys with Sn compositions up to 34%. However, the synthesis of nanocrystalline alloys has proven difficult due to larger discrepancies (~14%) in ...


Control Of Light-Matter Interaction Via Dispersion Engineering, Harish Natarajan Swaha Krishnamoorthy Oct 2014

Control Of Light-Matter Interaction Via Dispersion Engineering, Harish Natarajan Swaha Krishnamoorthy

All Dissertations, Theses, and Capstone Projects

This thesis describes the design, fabrication and characterization of certain nanostructures to engineer light-matter interaction. These materials have peculiar dispersion properties owing to their structural design, which is exploited to control spontaneous emission properties of emitters such as quantum dots and dye molecules. We will discuss two classes of materials based on the size of their unit cell compared to the wavelength of the electromagnetic radiation they interact with. The first class are hyperbolic metamaterials (HMM) composed of alternate layers of a metal and a dielectric of thicknesses much smaller than the wave- length. Using a HMM composed of silver ...


Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes Jun 2014

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses and Project Reports

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual ...


Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes Jun 2013

Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes

Materials Engineering

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength ...


Application Of Quantum Dots Onto Glass Wafers As A Feasibility Test For The Spectral Down Conversion Of Uv Light For Solar Cells, Anthony Fong Jun 2013

Application Of Quantum Dots Onto Glass Wafers As A Feasibility Test For The Spectral Down Conversion Of Uv Light For Solar Cells, Anthony Fong

Materials Engineering

Quantum dots have the ability to convert high energy photons into multiple lower energy photons. Down conversion of such high energy photons from sources such as UV light can be beneficial for applications on solar cells which waste much of the energy in the form of thermalization. To test this theory, a solar cell was hooked up to an Amprobe Solar Analyzer and tests were run to compare power output with and without the presence of quantum dots. Additionally, quantum dots were spin coated onto a glass wafer to determine its adhesion ability. Spectrometer readings were taken of the wafer ...


Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell, Christopher Marcus Botros, Richard N. Savage Dec 2012

Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell, Christopher Marcus Botros, Richard N. Savage

Master's Theses and Project Reports

Research to increase the efficiency of conventional solar cells is constantly underway. The goal of this work is to increase the efficiency of conventional solar cells by incorporating quantum dot (QD) nanoparticles in the absorption mechanism. The strategy is to have the QDs absorb UV and fluoresce photons in the visible region that are more readily absorbed by the cells. The outcome is that the cells have more visible photons to absorb and have increased power output. The QDs, having a CdSe core and a ZnS shell, were applied to the solar cells as follows. First, the QDs were synthesized ...


The Design And Fabrication Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Robert Gonsalves Feb 2012

The Design And Fabrication Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Robert Gonsalves

Master's Theses and Project Reports

A microfluidic reactor for synthesizing cadmium selenide (CdSe) quantum dots (QDs) was synthesized out of a silicon wafer and Pyrex glass. Microfabrication techniques were used to etch channels into the silicon wafer. Holes were wet-drilled into the Pyrex glass using a diamond-tip drill bit. The Pyrex wafer was anodically bonded to the etched silicon wafer to enclose the microfluidic reactor. Conditions for anodic bonding were created by exposing the stacked substrates to 300V at ~350oC under 5.46N of force. A syringe containing a room temperature CdSe solution was interfaced to the microfluidic reactor by using Poly (dimethylsiloxane) (PDMS) as ...


The Design And Manufacture Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Gonsalves Jun 2011

The Design And Manufacture Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Gonsalves

Materials Engineering

A microfluidic reactor for synthesizing cadmium selenide (CdSe) quantum dots (QDs) was synthesized out of silicon and Pyrex glass. Microfabrication techniques were used to etch the channels into the silicon wafer. Holes were wet-drilled into Pyrex glass using a diamond-tip drill bit. The Pyrex wafer was aligned to the etched silicon wafer and both were anodically bonded to complete the microfluidic reactor. Conditions for anodic bonding were created by exposing the stacked substrates to 300V at ~350oC under 5.46N of force. Bulk CdSe solution was mixed at room temperature and treated as a single injection. The syringe ...


Studies On The Preparation And Luminescence Properties Of Cadmium Selenide Quantum Dots, Their Immobilization, And Applications., Travis Justin Heath Dec 2010

Studies On The Preparation And Luminescence Properties Of Cadmium Selenide Quantum Dots, Their Immobilization, And Applications., Travis Justin Heath

Electronic Theses and Dissertations

Quantum dots are semiconductive particles whose properties are highly influenced by the presence of at least one electron. Cadmium selenide quantum dots were synthesized via colloidal synthesis. Contrary to previous preparations, more focus was placed on the temperature rather than the duration of time at which they form. A series of colored solutions were obtained because the excited quantum dots of various sizes emitted specific wavelengths of light. The emission spectra showed that the temperature-dependent quantum dots were successfully synthesized. The quantum dots were also immobilized on various surfaces, and the luminescence properties were examined. The quantum dots that were ...