"Photovoltaics offer a viable solution to our growing energy needs. Conventional solar panels can meet these needs if installed over a large enough area, however achieving this is difficult due to high installation costs and lack of aesthetic appeal. Visibly transparent photovoltaics that selectively absorb ultraviolet and near-infrared light allow seamless integration over previously inaccessible surfaces such as windows or electronic displays, and can thus complement existing solar deployment in a significant way. Enhancing commercial viability for a greater range of these applications requires high power conversion efficiency, a large catalog of wavelength-selective photoactive materials, and long lifetime. In this work, we investigate several approaches toward complete optimization for these important devices. We first explore alternative electrode materials as a replacement for a widely used organic buffer layer which can improve device durability. Next, we demonstrate near-infrared selective organic molecular salts that exhibit uniquely decoupled absorption and molecular orbital energy level tunability. The effects of anion exchange on the solubilities and surface energies of the collective salts are also explored. We further investigate the structural effects of several near-infrared selective molecules and salts to identify key metrics to guide the design of long lifetime materials. This is the first comprehensive lifetime study on devices featuring organic salts with varied counterions. As a result, we show dramatically enhanced device lifetimes of over 7 years under typical solar illumination, exceeding the lifetimes of most mobile electronic devices. This work provides a roadmap to enhance the performance and robustness of transparent photovoltaics that can enable wide scale deployment"--Page ii.
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