Physical Sciences and Mathematics Commons^™

Transient Absorption Studies Of Cdse Nanocluster Passivated With Phenyldithiocarbamate Ligands., Yizhou Xie

Electronic Theses and Dissertations

Semiconductor nanocluster (SCNC) research is a rapidly growing field driven by the promising fact that properties of such materials can be tailored by modifying their size, shape, and structure. Combination of nanocluster and organic ligands provides even wider possibilities of design and development of effective and task-specific nanostructures. Understanding of and, eventually, control of energetics, interfacial interaction, and photoinduced processes in such highly heterogeneous structures is critical to invention of novel materials including those in photovoltaic devices. In the newly established Ultrafast Laser Facility (ULF), transient absorption pump-probe spectroscopy (TAPPS) has been employed to investigate the electron transfer (ET) and …

Functionalization Of Indium-Based Quantum Dots For Use As A Non-Viral Gene Therapy Vector, Nicholas A. Mundt

MSU Graduate Theses

This work aims to develop functionalized, water-soluble indium-based quantum dots (QDs) as a non-viral gene therapy vector. The QDs were solubilized in water by exchanging native hydrophobic surface ligands with 11-mercaptoundecanioc acid (MUA); an amphiphilic ligand providing terminal carboxylate groups that impart water solubility to the QDs. The aqueous QDs were then functionalized with a terminal tertiary amine to impart a positive surface charge, allowing negatively-charged DNA to complex with the nanoparticles. The QDs were characterized via electrophoresis to determine their ability to bind DNA. Results show that further work is needed to optimize DNA binding. In addition, this work …

Development Of Luminescent Quantum Dot-Enabled Nano- And Microplatforms For Multiplex Detection Of Biomarkers, Kristen S. Williams

University of New Orleans Theses and Dissertations

Luminescent semiconductor quantum dots (QDs) are extensively researched for use in biological applications. They have unique optical and physical properties that make them excellent candidates to replace conventional organic dyes for cellular labeling, multiplexing, nucleic acid detection, and as generalized probes. The primary focus of this dissertation was to utilize quantum dots for improvement in immunoassays. Specifically, atherosclerosis biomarkers were detected simultaneously in an effort to demonstrate advances in early detection diagnostics.

Quantum dot-antibody bioconjugates were prepared by encapsulation into mesoporous silica and functionalized with thiol and amine groups to enable bioconjugation. Functionalization of the mesoporous silica quantum dot composites …

Design And Fabrication Of Nanostructures For The Enhancement Of Photovoltaic Devices, Richard M. Prevost Iii

University of New Orleans Theses and Dissertations

In 2012 the net world electricity generation was 21.56 trillion kilowatt hours. Photovoltaics only accounted for only 0.1 trillion kilowatt hours, less than 1 % of the total power. Recently there has been a push to convert more energy production to renewable sources. In recent years a great deal of interest has been shown for dye sensitized solar cells. These devices use inexpensive materials and have reported efficiencies approaching 12% in the lab. Here methods have been studied to improve upon these, and other, devices. Different approaches for the addition of gold nanoparticles to TiO₂ films were studied. These …

Design Of 3d Macroporous Inverse Opal Tio2 Binary And Ternary Composites Sensitized With Gold Nanoparticles And Cds Quantum Dots For Photocatalysis, Daniel A. Corella

Master of Science in Chemical Sciences Theses

Materials composed of titanium (IV) oxide (TiO₂) have received enormous scientific interest due to titania’s abundance, non-toxicity, and photocatalytic proficiency, however its large band gap limits its applicability under ambient conditions. Various attempts have been made to incorporate titania into composite systems to sensitize it for activity under a broader range of wavelengths. One such method includes utilizing narrow band gap semiconductors to form an electron transfer process analogous to photosynthesis referred to as a Z-scheme. Z-scheme systems can catalyze the decomposition of aqueous pollutants via generation of reactive oxygen species after input of sunlight. This work reports …

Chalcogenide Nanocrystal Assembly: Controlling Heterogeneity And Modulating Heterointerfaces, Jessica Davis Davis

Wayne State University Dissertations

This dissertation work is focused on developing methods to facilitate charge transport in heterostructured materials that comprise a nanoscale component. Multicomponent semiconductor materials were prepared by (1) spin coating of discrete nanomaterials onto porous silicon (pSi) or (2) self-assembly. Spin-coating of colloidal quantum dot (QD) PbS solutions was employed to create prototype PbS QD based radiation detection devices using porous silicon (pSi) as an n-type support and charge transport material. These devices were initially tested as a photodetector to ascertain the possibility of their use in high energy radiation detection. Short chain thiolate ligands (4-fluorothiophenolate) and anion passivation at the …