UCLA

As humanity's energy consumption continues to increase for the coming decades, with our knowledge of traditional fossil fuels' deleterious effects on our planetary ecosystem, it is evident that development of clean, economical, and renewable energy sources is one of the great remaining problems faced by our species. Photovoltaic technologies, particularly those based on organic materials, have been suggested as potentially viable solutions to our energy demands. However, several deficiencies of organic photovoltaic devices, specifically their relatively low power conversion efficiency, has hampered their adoption for large-scale energy production. One of the main causes of these deficiencies is the imprecise control of the distribution of the active materials within these photovoltaic devices. This dissertation presents a series of semiconductor device modeling simulations, which were conducted to elucidate the various effects of the morphology of active components on organic photovoltaic devices' charge transport properties and photovoltaic performance. Our simulations illustrate how subtle variations in the active layer morphology can both hinder and benefit device performance in surprising ways. This indicates the need for novel processing techniques, which allow precise control of device morphology, in order for organic photovoltaic devices to be competitive with other contemporary renewable energy technologies.