No description available.

No description available.

Thesis (Ph. D.)--Columbia University, 1915. / Vita. Published also as Studies in history, economics and public law, ed. by the Faculty of political science of Columbia university, vol. LXI, no. 1, whole no. 148.

published_or_final_version / abstract / Physics / Master / Master of Philosophy

Monomers and polymers containing the quinodimethane unit were synthesized. The infrared, nuclear magnetic resonance (NMR) and ultraviolet spectra of these materials were also reported. Oxidation of the enolate dianoion of α, α'-di(carbomethoxy)-α, α'-diphenylquinodimethane (DMPQH₂) with iodine gave 7,8-di(carbomethoxy)-7,8-diphenylguinodimethane (DMPQ) in greater than 50% yield. This compound had a reduction potential of -0.85V (Ag/AgCl reference) but would not form charge transfer complexes with electron donors. Attempted polymerization reactions of DMPQ were also discussed. A series of donor - acceptor substituted quinodimethanes was synthesized and a discussion of their electronic properties was included. Condensation copolyesterification of two of these materials was performed. Polymers with inherent viscosities ranging from 0.11 dL/g to 0.45 dL/g were obtained. The polymers were soluble at room temperature in hexafluoroisopropanol (HFIP) and a 1 : 1 solution of phenol/chlorobenzene. The polymers were also soluble at elevated temperatures in dipolar aprotic solvents.

This thesis describes results obtained using high resolution electron microscopy, acoustic microscopy and chemical analysis to study the structure and properties of the superionic β-aluminas. The acoustic microscopy and chemical analysis results relate solely to sodium β- and β -alumina, which are used as the solid state electrolyte in the sodium/sulphur cell. The high resolution electron microscopy results cover sodium β- and β-alumina as well as a number of ion-exchanged β-aluminas. The β-alumina structure consists of spinel-like blocks separated by the so-called conduction planes. The conduction planes have a low density, and contain all the mobile cations. Lattice images of sodium β- and β-alumina, silver β-alumina, ammonium/hydronium β-alumina, gadolinium β -alumina and divalent and trivalent europium β -alumina are presented and discussed. A hitherto unreported long-period structure in sodium β-alumina is shown, as is superlattice ordering in the divalent and trivalent β-aluminas. Defects in these materials are also discussed. The most common damage mode in the β -aluminas, due to electron beam irradiation, is the loss of the mobile-ion containing planes, and the subsequent collapse and shear of the structure to form broad defect spinel blocks. It is shown that collapse vectors determined for sodium β-alumina can also be applied to ammonium/hydronium β-alumina. Two further damage modes observed in this β-alumina are also discussed. A damage mode has been observed in sodium B-alumina and silver β-alumina which involves the extrusion of material to the crystal surface. Electron diffraction patterns from the extruded material have been indexed. The acoustic microscope has been used to examine bulk sodium β/β-alumina electrolyte tube specimens. Images of rectangular features present in the tubes (approximately 40um in length) are presented and the possible nature of the features is discussed.

Organic solar cells and organic light emitting diodes are on the forefront of emerging technologies aimed at harnessing light in ways never thought possible. Largear installations of OLED solid state lighting (SSL), as well as organic photovoltaics(OPVs), will become possible as the efficiencies of these devices continue to rise. All organic solar cells and OLEDs require the use of transparent conductive electrodes.Indium oxide (ITO) is currently the transparent conductor of choice for these applications, due to its unique combination of transparency, high conductivity, durability,and favourable surface properties. Indium, however, is a rare and expensive metal; proposed large-area installations of OPV cells and OLEDs will add further strain to global indium supply. Transparent conductive materials that are abundant, inexpensive, and which enable efficient and robust organic devices must therefore be developed. In the present work, suitable ITO anode replacement materials are demonstrated for OLEDS, small-molecule, polymer, and PbS colloidal quantum dot photovoltaics.

Organic solar cells and organic light emitting diodes are on the forefront of emerging technologies aimed at harnessing light in ways never thought possible. Largear installations of OLED solid state lighting (SSL), as well as organic photovoltaics(OPVs), will become possible as the efficiencies of these devices continue to rise. All organic solar cells and OLEDs require the use of transparent conductive electrodes.Indium oxide (ITO) is currently the transparent conductor of choice for these applications, due to its unique combination of transparency, high conductivity, durability,and favourable surface properties. Indium, however, is a rare and expensive metal; proposed large-area installations of OPV cells and OLEDs will add further strain to global indium supply. Transparent conductive materials that are abundant, inexpensive, and which enable efficient and robust organic devices must therefore be developed. In the present work, suitable ITO anode replacement materials are demonstrated for OLEDS, small-molecule, polymer, and PbS colloidal quantum dot photovoltaics.

In the past three decades, quasi-low-dimensional organic materials have attracted intense interests, both experimentally and theoretically. Due to their reduced dimensionality and relatively low carrier concentration, many organic materials exhibit strong electron correlations and numerous instabilities of the normal metallic state. The energy scales of such instabilities are often so low that the ground states can be changed by applying a reasonably strong magnetic field. Therefore, magnetic field is an effective tool for the study of quasi-low-dimensional organic materials. In this thesis, we will investigate two of these magnetic field related phenomena. In the first part, we will present our unified theory of angular magnetoresistance oscillations observed in organic conductors. We will demonstrate that, in spite of the absence of Landau level quantization for open Fermi surfaces in a magnetic field, a new quantum effect - Bragg reflections of electrons moving in the extended Brillouin zone - determines unusual magnetic properties of these materials. We will demonstrate that, at commensurate directions of a magnetic field, the electron motion shows 1D→2D dimensional crossover and leads to strong resistivity minima. We will present an analytic expression for interlayer resistivity, by both linear response formalism and solving the Boltzmann kinetic equation in the extended Brillouin zone. In two limiting cases, our general solution reduces to the results previously obtained for the LMA effects and LNL oscillations. We demonstrate that our theoretical results are in good qualitative and quantitative agreement with the existing measurements of resistivity in (TMTSF)₂ClO₄ conductor. In the second part, we will develop a theory for the recently observed high magnetic field high resistance state in (Per)₂Pt(mnt)₂. We demonstrate that the Pauli spinsplitting effects in a magnetic field improve nesting properties of a realistic quasi-onedimensional electron spectrum. As a result, a high resistance Peierls charge-density wave (CDW) phase is stabilized in high enough magnetic fields in (Per)₂Pt(mnt)₂ conductor. We show that, in low and very high magnetic fields, the Pauli spin-splitting effects lead to a stabilization of a soliton wall superlattice (SWS) CDW phase, which is characterized by periodically arranged soliton and anti-soliton walls. We suggest experimental studies of the predicted first order phase transitions between the Peierls and SWS phases to discover a unique SWS phase. It is important that, in the absence of a magnetic field and in a limit of very high magnetic fields, the suggested model is equivalent to the exactly solvable model of Brazovskii, Dzyaloshinskii, and Kirova.

No description available.