Physical Sciences and Mathematics Commons^™

Organic Solar Cells: Electrodes, Performance Enhancement And Degradation Mechanisms, Reginald J. Bauld

Electronic Thesis and Dissertation Repository

In this thesis I focus on a number of aspects associated with the fabrication and characterization of organic photovoltaics. Specifically, my work focuses on evaluating solution processed graphene electrodes for use in organic photovoltaics, improving the performance of indium tin oxide transparent contacts by coating them with Au nanoparticles, and understanding the degradation pathways of Poly(3-hexylthiophene-2,5-diyl): Phenyl-C61-butyric acid methyl ester (P3HT:PCBM) organic solar cells. In my work on graphene electrodes for organic solar cells I worked out a relationship between the sheet resistance and the film transmittance that is useful to optimize such electrodes. Investigation of organic solar cell degradation …

Defect-Related Magnetic And Electronic Properties Of Graphene, Arash Akbari-Sharbaf

Electronic Thesis and Dissertation Repository

A fundamental study of the electronic and magnetic properties of graphene modified by defects is presented. This work includes both theoretical and experimental investigations of graphene, graphene-metal composites and related structures, together with edge effects. The theoretical model employed for the description of p-electrons in graphene is based on the tight-binding Hamiltonian. On the experimental side we place special emphasis on the electron spin resonance technique (ESR).

After describing the theoretical and experimental methods, we first investigate the origin of paramagnetism in graphene nanoribbons (GNRs) using a combination of ESR and other characterisation techniques, corroborated by a theoretical model. …

Quantum Optics Of Polaritonic Nanocomposites, Chris Racknor

Electronic Thesis and Dissertation Repository

In this thesis, we study the quantum optical interaction in polaritonic nanocomposites. These systems are made by the combination of two or more micro- or nano-scale structures with complementary optical properties, such as polaritonic materials, excitonic materials, photonic crystals (PCs), quantum dots (QDs), waveguides, couplers, metal nanorods (MNRs), bionanoparticles. The nanocomposites systems studied included QDs doped within a polaritonic PC, an excitonic waveguide coupler, and a metamaterial waveguide. Also addressed are systems consisting of MNRs paired with biological labelling dye or QDs.

The application of a strain field, known as the acousto-optic effect, was found to control photon transmission in …

I. Accurate 50-200 Kev Proton Stopping Cross Sections In Solids Ii. Lateral Growth Of Si Wires On Si (100) Substrate, Sergey Dedyulin

Electronic Thesis and Dissertation Repository

Medium energy ion scattering (MEIS) is used to determine the elemental depth profile in the first few hundred angstroms of a sample. The interpretation of MEIS spectra requires an accurate knowledge of the rate at which the ions lose their energy - the stopping cross section, ε. The rate of energy loss has been fairly well investigated, both experimentally and theoretically, in elemental and compound targets at high energies (E>400 keV/amu). However, in the medium ion energy range where stopping cross section typically has a maximum, experimental data are scarce while most of the existing theories fail to give …

A Molecular Simulation Study On Micelle Fragmentation And Wetting In Nano-Confined Channels, Mona Habibi

Electronic Thesis and Dissertation Repository

We performed coarse-grained molecular-dynamics (MD) simulations to study the structural and dynamical properties of surfactant micelles in equilibrium and under Poiseuille-like flow in a nano-confined geometry. We used the MARTINI force-field to model the interactions between water molecules, counter-ions, and sodium dodecyl sulfate (SDS) surfactants. SDS surfactant was chosen as the standard model because of its potential application in drug delivery systems. First, we focused on the self-assembly of SDS in equilibrium. To form stable spherical mi- celles, we ran simulations in the isothermal-isobaric ensemble (NPT) on a system of free SDS surfactants, counter-ions and water molecules. We studied the …