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<p> Integrating solar energy into the electric vehicle (EV) market alleviates the demand for</p> <p>fossil fuels used to generate the electricity used to power these vehicles. Integrated solar panels</p> <p>provide a new method of power generation for an electric vehicle, but researchers must consider</p> <p>new dependent variables such as drag in the figure of vehicle efficiency. For the solar array to be</p> <p>deemed a viable option for power generation, the solar array must generate enough energy to</p> <p>overcome the added weight and aerodynamic drag forces the solar system introduces. The thesis</p> <p>explores the application of photovoltaic modules for power generation in an EV system.</p> <p>Researchers installed an off-the-shelf solar module on the roof of an EV and investigated the</p> <p>system to explore the efficiency tradeoffs. The research sought to identify an optimized solar</p> <p>panel configuration for minimized drag based on maximized panel surface irradiance, cooling,</p> <p>and array output voltage parameters. The study utilized computational fluid dynamics modeling,</p> <p>wind tunnel testing, and full-scale track testing to analyze the system. The results of this study</p> <p>provide an optimized configuration for a Renogy RNG-100D atop a Chevrolet Bolt. The system</p> <p>was considered optimal at a tilt angle of zero degrees when in motion. The performance benefits</p> <p>due to the increased angle of the solar panel tilt were deemed insufficient in overcoming the</p> <p>aerodynamic drag forces introduced into the system while in motion.</p>

<p dir="ltr">Two-dimensional (2D) perovskite semiconductors are an emerging family of hybrid materials featuring a built-in quantum well architecture which has gained much interest due to its potential as a promising candidate for next-generation photovoltaic and optoelectronic applications. To successfully integrate 2D perovskites as efficient devices, it is imperative that a thorough understanding of the fundamental properties these materials possess and how their complex heterostructures behave is established. However, to date, the synthetic challenges regarding high-quality crystals of these materials due to the structural complexity and the hybrid nature have impeded further progress in this area. Thus, we demonstrate a general method to construct tunable 2D organic semiconductor-incorporated perovskites (OSiP) by simultaneously manipulating slab thickness of the inorganic layers and conjugation length of the organic substituents. The energy band offsets and exciton dynamics at the organic-inorganic interfaces were elucidated using computational means and ultrafast spectroscopy, while lattice dynamics were quantified via temperature-dependent spectroscopy and X-ray diffraction studies. Results show that longer and more planar π-conjugated organic ligands induce a more rigid inorganic crystal lattice, which leads to suppressed exciton-phonon interactions and superior optoelectronic properties such as efficient lasing.</p><p dir="ltr">Furthermore, understanding ion migration in two-dimensional (2D) perovskite materials is key to enhancing device performance and stability as well. However, prior studies have been primarily limited to heat and light-induced ion migration. To investigate electrically induced ion migration in 2D perovskites, we construct a high-quality single crystal 2D perovskite heterostructure device platform with near defect-free van der Waals contact. While achieving real-time visualization of directional ion migration, we also uncover the unique behavior of halide anions inter-diffusing towards the opposite direction under prolonged bias. Confocal microscopy imaging reveals a halide migration channel that aligns with the crystal and heterojunction edges. After sustained ion migration, stable junction diodes exhibiting up to ~1000-fold forward to reverse current ratio are realized. Unraveling the fundamental properties of 2D OSiPs as well as ion migration in 2D perovskite heterostructures paves the way towards stable and efficient devices.</p>

<p dir="ltr">Transitioning to a carbon-neutral future will require a broad portfolio of green energy generation and storage solutions. With the abundant availability of solar radiation across the Earth’s surface, energy generation from photovoltaics (PVs) will be an important part of this green energy portfolio. While silicon-based solar cells currently dominate the PV market, temperatures exceeding 1000 °C are needed for purification of silicon, and batch processing of silicon wafers limits how rapidly Si-based PV can be deployed. Furthermore, silicon’s indirect band gap necessitates absorber layers to exceed 100 µm thick, limiting its applications to rigid substrates.</p><p dir="ltr">Solution processed thin-film solar cells may allow for the realization of continuous, high-throughput manufacturing of PV modules. Thin-film absorber materials have direct band gaps, allowing them to absorb light more efficiently, and thus, they can be as thin as a few hundred nanometers and can be deposited on flexible substrates. Solution deposition of these absorber materials utilizing molecular precursor-based inks could be done in a roll-to-roll format, drastically increasing the throughput of PV manufacturing, and reducing installation costs. In this dissertation, solution processed synthesis and the characterization of two emerging direct band gap absorber materials consisting of earth abundant elements is discussed: the enargite phase of Cu₃AsS₄ and the distorted perovskite phase of BaZrS₃.</p><p dir="ltr">The enargite phase of Cu₃AsS₄ (ENG) is an emerging PV material with a 1.42 eV band gap, making it an ideal single-junction absorber material for photovoltaic applications. Unfortunately, ENG-based PV devices have historically been shown to have low power conversion efficiencies, potentially due to defects in the material. A combined computational and experimental study was completed where DFT-based calculations from collaborators were used inform synthesis strategies to improve the defect properties of ENG utilizing new synthesis techniques, including silver alloying, to reduce the density of harmful defects.</p><p dir="ltr">Chalcogenide perovskites are viewed as a stable alternative to halide perovskites, with BaZrS₃ being the most widely studied. With a band gap of 1.8 eV, BaZrS₃ could be an excellent wide-bandgap partner for a silicon-based tandem solar cell.Historically, sputtering, and solid-state approaches have been used to synthesize chalcogenide perovskites, but these methods require synthesis temperatures exceeding 800 °C, making them incompatible with the glass substrates and rear-contact layers required to create a PV device. In this dissertation, these high synthesis temperatures are bypassed through the development of a solution-processed deposition technique.A unique chemistry was developed to create fully soluble molecular precursor inks consisting of alkaline earth metal dithiocarboxylates and transition metal dithiocarbamates for direct-to-substrate synthesis of BaZrS₃ and BaHfS₃ at temperatures below 600 °C.</p><p dir="ltr">However, many challenges must be overcome before chalcogenide perovskites can be used for the creation of photovoltaic devices including oxide and Ruddlesden-Popper secondary phases, isolated grain growth, and deep level defects. Nevertheless, the development of a moderate temperature solution-based synthesis route makes chalcogenide perovskite research accessible to labs which do not have high temperature furnaces or sputtering equipment, further increasing research interest in this quickly developing absorber material.</p>