SBIR Phase II: Understanding the Lifetime of Perovskite/Silicon Tandems for Vehicle-Integrated Photovoltaic and Residential Applications

The broader/commercial impact of this Small Business Innovation Research Phase II project is to advance a new class of high-efficiency solar panels capable of generating substantially more electricity without increasing installation footprint. The project will address a major limitation of current solar technology: efficiency limits that constrain energy output and system economics. By developing durable tandem solar cells that combine complementary light-absorbing materials, this project will enable solar modules that deliver significantly higher power density than today’s conventional silicon solar panels. Higher efficiency reduces balance-of-system costs, expands rooftop and vehicle-integrated solar opportunities, and lowers the overall cost of electricity. This work advances energy innovation, strengthens domestic manufacturing capability, and supports economic growth. This project addresses the high-risk challenge of scaling perovskite–silicon tandem solar cells to full commercial size while meeting industry-standard reliability requirements. The central innovation is a tandem device architecture that enables low-cost, solution-based deposition of perovskites onto industry-standard silicon solar cells using low-temperature metallization and interconnection processes compatible with thermally sensitive materials. This architecture integrates controlled large-area coating over textured silicon surfaces, interfacial planarization to suppress defect formation, and stress-managed interconnection strategies that maintain mechanical integrity during module fabrication and environmental exposure. The scope of the project includes scaling tandem solar cells to full wafer dimensions with target efficiencies exceeding 27%, developing lightweight and glass-based module configurations, and validating long-term durability under International Electrotechnical Commission qualification standards. The project will also include outdoor field testing to quantify real-world degradation rates and develop physics-based lifetime models that correlate accelerated stress testing with in-field performance. Methodologies will include large-area coating optimization, metallization and grid redesign to minimize resistive losses, moisture barrier evaluation for lightweight modules, ultraviolet exposure threshold characterization, reverse-bias performance testing, and multi-site outdoor monitoring with maximum power point tracking. The intellectual contribution is a validated engineering framework that links large-area processing, stress management, and environmental durability to predictable field lifetime performance of perovskite-silicon tandem technology. 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.