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Polymer light emitting electrochemical cells (LECs) are solid-state devices containing an active layer blend of luminescent polymer, ion transport material and salt sandwiched between two electrodes. They operate on the principal of in situ electrochemical doping. Doping entails the injection of electronic charge from the electrodes, causing the reduction/oxidization of the luminescent polymer, and accompanied by charge compensation through the redistribution of salt counter-ions. Due to the high conductivity of the doped polymer, a fully turned on LEC has a dramatically reduced contact and bulk resistance. This gives the LEC certain intrinsic advantages such as balanced charge injection, low operating voltage and high quantum efficiencies, even when stable metal or symmetric electrodes are used. These properties have led to the popular assumption that the electrode work function is not a critical device parameter for LEC operation. In this thesis, I describe my original research to determine how the electrode composition influences LEC performance. A series of sandwich and planar configuration LECs with various electrodes on identical MEH-PPV (poly[5-(2-ethylhexyloxy)-2-methoxy-1,4-phenylene vinylene]):PEO (poly ethylene oxide):LiTr (Lithium trifluoromethanesulfonate) based films are constructed. I demonstrate that the doping profile, doping propagation speed, emission zone shape, emission zone location, electro-luminescence (EL) turn-on, and EL efficiency are all strongly affected by the choice of electrode materials. LECs with asymmetrical electrodes optimized for both electron and hole injection result in the best overall performance. Using an optimized electrode configuration, I am able to realize extremely large crown ether based planar LECs. MEH-PPV: dicyclohexano-18-crown-6 (DCH18Cr6): LiTr and 108GE:DCH18Cr6:LiTr devices with various symmetric and asymmetric electrode configurations were constructed, where 108GE is the fluorene copolymer poly[(9,9-dioctyl-2,7-divinylene-fluorenylene)-alt-co-(2-methoxy-5-(ethylhexyloxy)-1,4-phenylene)]. I demonstrate ii i and image the first ever crown ether-based planar LECs with millimeter inter-electrode spacing. Due to minimal phase separation, crown ether-based LECs display highly uniform doping propagation and very smooth emission zones. Junction relaxation, de-doping and reverse bias operation experiments are also presented, and results compared to behavior in PEO based LECs. Additionally, I demonstrate that crown ether-based LECs do not exhibit frozen junction behavior at room temperature. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2008-09-23 16:15:06.569

Photonic crystals are optical materials where patterning of dielectrics on sub-wavelength length scales creates unusual optical properties such as waveguides with propagation speeds much slower than the vacuum speed of light. In this thesis, I examine the classical and quantum optical properties of such structures, specifically the enhancement of photon emission rate from a single quantum dot embedded in the waveguide (the Purcell Effect) and extrinsic scattering from an injected waveguide mode due to fabrication imperfections. The photon emission rate is found to be significantly enhanced over a large bandwidth in slow light photonic crystal waveguides and I provide detailed results for optimizing the emission properties of a novel photonic crystal ridge waveguide to suite a given application. Using an incoherent scattering theory, I show how slow light propagation enhances extrinsic scattering from unavoidable manufacturing imperfections leading to back scattering and radiation loss that scale with the group velocity v_g, as v_g^{-2} and v_g^{-1} respectively. I then improve the modeling of scattering using a coherent, multiple scattering approach to explain the experimental observation of disordered resonances in slow light waveguide modes. The theoretical predictions show good agreement with experimental measurements. This document provides a thorough introduction to the properties and problems of slow light photonic crystal waveguides. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-09-03 12:29:01.696

A New Community Park for Wellness presents a new vision for parks. It proposes a new era of park programming, the ‘Community Wellness and Holistic Health Era’ in order to improve our communities with design that highlights natural phenomena. Today, health is no longer about disease or death; it’s about maintenance - getting outside, having access to fresh food and living a balanced lifestyle. Drawing on historical and contemporary wellness precedents, this practicum aims to create a community destination that promotes health and prevents disease in Winnipeg, Manitoba. It documents investigations into park programming and design, current trends in health and wellness, potential roles of light and water in landscape architecture, and light in modern and post-modern Scandinavian architecture. The final design emphasizes natural phenomena and processes related to light, water and energy in order to promote health and reconnect urban residents with time, place and the changing seasons.

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