SBIR Phase I: SnO2 Layers for Scalable Fullerene-Free Perovskite Solar Cells

The broader impact of this Small Business Innovation Research (SBIR) Phase I project is to address key barriers preventing perovskite solar technology from reaching commercialization. Current high-performance perovskite solar devices utilize materials and processes that are expensive and difficult to scale. This project develops a new class of liquid-processable tin oxide nanoparticles that are affordable and compatible with industrial coating methods. By improving these materials, the aim is to lower the cost of solar manufacturing while increasing module performance and lifetimes. This work strengthens the domestic energy sector by enabling cost-competitive domestic production of high-performance solar materials. Reducing reliance on expensive fabrication technologies and foreign supply chains strengthens energy security and supports broader solar deployment. The project also advances understanding of the key electrical properties and process parameters needed to overcome current performance limitations. This project investigates how solution-processed SnO₂ nanoparticle films can be engineered to achieve the coating uniformity and electronic quality required for high-performance, scalable perovskite solar cells. Achieving this in a solution-processed system is inherently challenging because small variations in nanoparticle surface chemistry, ink stability, and film formation can significantly alter interfacial reactions and electrical behavior. These tightly coupled factors govern resistive losses, charge extraction, and overall device performance, making consistent, high-quality film formation difficult to achieve at scale. The work focuses on establishing clear relationships between ink formulation, thin film properties, and processing conditions to enable consistent, high-quality electron transport layers. By studying the material system across solution, thin film, and device-integrated states, the project will develop structure–process–performance relationships that link material design to functional outcomes. These insights will guide both material optimization and scalable manufacturing strategies for fullerene-free perovskite solar cells. Experimental efforts will evaluate how variations in ink chemistry and processing influence film formation and interfacial behavior, with particular emphasis on ink stability, uniformity, electronic performance, and device stability. Coated films will be assessed under scalable deposition methods, and device-level testing will be used to quantify performance metrics such as resistive losses, hysteresis, and operational stability. 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.