This Small Business Technology Transfer (STTR) Phase I project aims to develop roll-to-roll processing of highly efficient, thin film photovoltaics on inexpensive polycrystalline substrates. The innovation lies in an architecture that yields near-single-crystalline thin films even on polycrystalline substrates. This innovation will be combined with the benefits of hot wire chemical vapor deposition (HWCVD) for Si film deposition. A key objective of this project is to demonstrate a high-rate HWCVD process for epitaxial Si layer on single-crystalline-like templates to fabricate high-efficiency solar cells on metal substrates. A strong emphasis will be placed on minimizing sources of defects and developing a comprehensive understanding of the impacts of these parameters on structural, electronic and photovoltaic properties of epitaxial thin film heterostructures. The broader/commercial impact of this project will be the potential to provide a viable solution that enables high efficiency and low manufacturing cost without using scarce materials in Photovoltaics devices. In addition to commercial potential, a strong understanding of the mechanisms of epitaxial growth, grain boundaries, and defect generation and propagation is expected to be derived from this work.
