This grant supports research that contributes new knowledge related to a novel process for manufacturing solar panels. This research focuses on perovskite solar cells, a new type of solar cell with the potential to revolutionize the solar cell industry due to power conversion efficiencies that surpass those of state-of-the-art solar technologies. However, perovskite solar cells are currently made using slow, low yield, laboratory-scale processes that are not amenable to be scaled up to the large areas and high throughputs required for industrial production. To overcome these barriers, this project investigates a continuous slot-die coating and crystallization process that enables the fabrication of high-quality perovskite thin films, and ultimately large-area solar panels, at high speed and low cost. Perovskite solar panels have the potential to provide electricity at lower cost than other solar technologies and could provide a boost to the U.S. renewable energy industry. This research involves several disciplines including manufacturing, engineering, and materials science and helps broaden participation of women and students from underrepresented minority groups in research and positively impacts engineering education.
Efficient, low-cost photovoltaics (PVs) based upon perovskites have the potential to transform the global energy portfolio. The greatest remaining challenge in perovskite PVs is the development of scalable, rapid manufacturing strategies that maintain the perovskite performance at low cost. Prior knowledge of processing-structure-property relationships in PV films shows that performance depends on microstructure, composition, thickness, uniformity, and stability of the wet film during deposition, drying, and thermal treatment. This project focuses on understanding the crystallization and microstructure formation during slot-die coating, drying, and annealing processes as well as validating transport and kinetic models with experiments to control the properties of the perovskite films during processing and scale-up. The key scientific outcomes are rheological and interfacial assessment of slot-die ink formulations, a predictive nucleation and growth model accounting for thermal and concentration gradients during slot-die coating, validation of retrograde solubility (i.e. inverse temperature crystallization) as an engineering control for crystal nucleation, and evaluation of double slot-die coating to create composition gradients and thereby decouple crystallization from drying. This allows for rationally designed inks for perovskite synthesis and a road map to address the challenges of coupled drying and crystallization common to rapid polycrystalline thin-film manufacturing processes.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
