The vast majority of solar photovoltaic (PV) cells are based on single-junction silicon (Si) cell designs. Tremendous manufacturing process optimization over the past several decades has led to large-scale, low-cost production of cells with 20-25% efficiency. However, fundamental materials limitations hinder significant improvements in Si cells beyond 25% conversion efficiency. Tandem (multi-junction) PV devices can exceed this limitation by layering two materials that absorb different portions of the solar spectrum to reach theoretical conversion efficiencies around 46% and commercial practical efficiencies around 35%. However, traditional tandem cells are expensive to manufacture, due in part to the materials used, and cells are limited in active area size. A new class of perovskite thin film absorber materials are inexpensive, can be processed at low temperatures from solution, and have near-ideal optical properties to compliment established single-junction Si PVs for production of high-efficiency tandem devices. However, fabrication of high-performance perovskite PVs in a manner compatible with high-volume manufacturing has yet to be demonstrated. Solving this challenge will allow for the mass production of high-efficiency tandem PV cells enabling higher power output for a given panel area at lower total system cost.
Project Innovation + Advantages:
Tandem PV will develop and test an advanced processing tool that integrates high-throughput solution deposition and precise drying to deposit large-area perovskite thin films of exceptional optical and electronic quality. Production of these films on large areas is a critical step towards perovskite-Si tandem PV cells that can achieve significantly higher efficiency than traditional Si PV cells. Small-scale perovskite PV device fabrication typically occurs using a spin-coating process, but the process is not easily scalable. The ability to deposit perovskite PV devices with a large-scale production technique while achieving the same quality and stability achieved by record-setting spin-coated laboratory cells would be a significant step forward. If the project is successful, it will remove a major obstacle to the successful commercialization of perovskite PVs.