Engineering Commons^™

Strategies For Controlling Bulk Heterojunction Morphology, Zach Daniel Seibers

Doctoral Dissertations

Organic photovoltaic devices have been extensively studied as a means to produce sustainable energy. However, the performance of organic-photovoltaic (OPV) devices is dependent upon a number of factors including the morphology of the active layer, device architecture, and processing conditions. Recent research has indicated that fullerenes in the bulk heterojunction are entropically driven to the silicon and air interfaces upon crystallization of P3HT, which occurs during thermal annealing. The first chapter of this research focuses on investigating the structure and function of end-tethered poly(3-hexylthiophene) chains to a transparent electrode as an anode buffer layer. Neutron reactivity reveals that these P3HT …

Mass And Charge Transport In Hydrated Polymeric Membranes, Marshall T. Mcdonnell

Doctoral Dissertations

Mass and charge transport through hydrated polymer membranes has significant importance for many areas of engineering and industry. Multi-scale modeling and simulation techniques were used to study transport in relation to two specific membrane applications: (1) food packaging and (2) additives for polymer electrolytes.

Chitosan/chitin films were studied due to their use as a sustainable, biodegradable food packaging film. The effects of hydration on the solvation, diffusivity, solubility, and permeability of oxygen molecules in these films were studied via molecular dynamics and confined random walk simulations. With increasing hydration, the membrane was observed to have a more homogeneous water distribution …

Magnetic, Optical And Electrical Properties Of Electron-Hole Pairs In Polymer And Organo-Metal Halide Perovskite Photovoltaic Cells, Yu-Che Hsiao

Doctoral Dissertations

Organic polymer and organo-metal halide perovskite (OMHP) materials have attracted extensive attention during the past decade due to their various applications, like solar cells, light emitting diode, even lasing action (OMHP). Especially, the organo-metal halide perovskite solar cell shows a remarkable power conversion efficiency of about 20%, which is comparable to the amorphous silicon solar cell. Therefore, OMHP solar cell had been considered as a promising substitution for the next generation of renewable energy source. The OMHP materials contain both advantages of organic and inorganic semiconductors, like solution processable thin film fabrication, long-range ambipolar transport characteristics, high dielectric constants, low …