September 11, 2006 – HelioVolt Corp. and the National Renewable Energy Laboratory (NREL) are extending a cooperative R&D agreement to include development of nonvacuum nanomaterial-based deposition processes optimized for the company’s “FASST” manufacturing technology for thin-film CIGS (copper-indium-gallium-selenide) photovoltaics.

Conventional thin-film production relies on vacuum deposition to coat the material onto substrate, but such process can be capital-intensive, and difficult for depositing CIGS films, especially on large areas. Nonvacuum or atmospheric deposition processes, such as its FASST process, offer simpler manufacturing processes and lower costs, the company said.

CIGS spontaneously arranges itself at the nanoscale to create a percolation network that drastically reduces losses, making the material the most efficient and reliable thin-film for photovoltaics. HelioVolt’s flexible FASST process utilizes this property to print photovoltaic material in both vacuum and atmospheric conditions directly onto traditional construction materials, including architectural glass, steel, roofing, and polymers, in 80%-98% less time than conventional processes.

Earlier this year, WaferNews spotlighted the Austin, TX-based startup’s efforts to develop its low-temperature SOI-type thin-film transfer process for making low-cost CIGS photovoltaic cells, starting with using conventional 150mm semiconductor production tools and glass wafers, and extending the process to much larger areas and less conventional substrates. The process involves depositing two separate precursor films on two separate substrates with e-beam evaporation or sputtering, then pressing the two films together and heating them with a rapid thermal process, similar to low-temperature anodic bonding. The chemical reaction generated under heat and pressure forms a crystalline CIGS thin film on the substrate. The upper superstrate can then be reused to emboss the next substrate.