NSF Award
2418013
NON-TECHNICAL SUMMARY:<br/><br/>Most technological devices today rely on thin films at various stages of their production. Despite being a small fraction of the overall material used, these films—measuring just a few microns or less in thickness—play a crucial role in energy production, transmission, and storage. Traditional methods of fabricating thin films for energy applications involve vacuum deposition; while this produces high-quality films, it also demands significant energy input and expensive equipment. These requirements pose major obstacles to reducing the overall cost of thin film technologies. To address these challenges, this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research and the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry at NSF, explores solution-based methods for depositing thin films that are more energy-efficient and cost-effective. Central to this approach are liquid inks that, once applied to a surface, decompose during curing and heating to form the desired thin film. A primary goal of this project is developing liquid inks to create sulfosalt thin films (drawing inspiration from naturally occurring minerals) for solar energy applications. Additionally, the project aims to dissolve elemental allotropes of phosphorus to create a new class of inks for producing phosphide-containing thin films. An integral part of this project is providing research opportunities to students from Cerritos College, a minority-serving community college in Los Angeles County. Through a summer internship program in materials chemistry, community college students will data mine natural mineral targets at the Natural History Museum of Los Angeles. They will then attempt to convert these promising minerals into thin films and study their properties. This program aims to give students valuable STEM research experience, which is often unavailable at the community college level, thereby improving their chances of transferring to four-year institutions.<br/><br/>TECHNICAL SUMMARY:<br/><br/>There is significant interest in developing new inks for low-cost thin film deposition with an emphasis on expanding the flexibility of bulk materials that can be dissolved to generate these inks, impacting both composition and raw material costs. Thiol-amine-based inks meet these criteria. This project leverages the characteristics of thiol-amine inks to explore two novel directions in materials chemistry. First, the inherent flexibility of thiol-amine solvent-based ink formulation will be utilized for the compositionally controlled deposition of perovskite-inspired solar absorber thin films. These films will be based on environmentally stable, lead-free sulfosalt minerals containing cations with high-Z ns2 lone pairs. The research will investigate self-healing properties in these thin films, examine the extent of stereochemically active lone pair structural distortions using synchrotron techniques, and evaluate the most promising candidates as solar absorbers. Second, this project will extend thiol-amine solvents beyond the solution deposition of metal chalcogenide thin films. The solution-phase reaction of white and red allotropes of phosphorus with various zero-valent metals and/or the co-dissolution of Zintl anions with metal cations will be explored for the deposition of metal phosphide thin films using this entirely new class of inks.<br/><br/>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.
