This project will develop a new technique for fabricating thin films of copper indium selenide (CuInSe2) and its alloys for low-cost photovoltaic solar cells. Solar cell technologies based on CuInSe2 materials have achieved the highest sunlight-to-electricity conversion efficiencies of any polycrystalline thin-film photovoltaics technology. However, CuInSe2-based photovoltaic products have yet to be introduced into the commercial marketplace in large part due to the lack of simple, robust processes capable of depositing high-quality CuInSe2 films at low costs on large-areas with the high-volume reproducibility needed to commercial production. This project will explore a simple, self-limiting, non-vacuum, low-cost technique for fabricating CuInSe2 films for solar cells. The two basic steps are to form nanocrystalline precursor layers and to convert the precursor layers into large-grain polycrystalline CuInSe2 films. Phase I will demonstrate that dense, uniform precursor layers can be deposited using simple, non-vacuum processes and that the precursor layers can be converted into device-quality CuInSe2 alloy films. The key tasks are to demonstrate that planar, homogeneous precursor layers can be deposited at low temperatures using low-cost source materials and that precursor layers can be converted into dense, large-grain CuInSe2 alloy films suitable for fabricating state-of-the-art solar cells.
Commercial Applications and Other Benefits as described by the awardee: The process for depositing CuInSe2 alloy films for large-area, low-cost solar cells should provide significant cost savings and should accelerate the commercialization of CuInSe2 photovoltaic technology for a wide range of applications.