Thin-film PV – Recent advances in thin-film PV are beginning to gain interest in commercial and residential building markets, as well as continued interest in space and near-space applications. Thin-film PV uses thin-film coating technologies, similar to those used for putting metallic and transparent coatings on plastics and glass for food processing, architectural glass, mirrors, eyewear, etc.

The three most common thin-film technologies are amorphous silicon (a-Si), cadmium telluride (CdTe) and copper-indium-gallium-diselenide (CIGS). Of these, CIGS currently has demonstrated the highest laboratory efficiency at 19.5% (NREL, measured in earth conditions) with CdTe close behind. CIGS thin-film technologies can be placed on a wide variety of substrate materials making it possible to manufacture very lightweight, flexible solar cells on metals and plastics. To put it into perspective, the thickness of a flexible CIGS device is approximately the same as the thickness of a human hair, making it very flexible and lightweight

CIGS on Metal Foils – While CIGS on metallic foils are a good first step, this class of thin-film product does not fully address the basic needs of the space, near space and terrestrial markets. First, metallic foil substrates generally require that each cell must be manufactured as discrete components which then must be interconnected in series and/or in parallel (similar to how flashlight batteries are stacked) to meet the desired voltage and current output in a module. Second, integrating discrete cells into building materials for roofing, siding, and architectural applications becomes more costly and problematic. While this is merely an inconvenience for earth applications, space applications require significant quality control for each process step of the PV array, thus adding to the cost and complexity of the power system. . Finally, many of the metallic substrates can interact with the magnetic fields around the earth. While not a concern for earth applications, any outside forces in addition to gravity that act on the spacecraft means that additional onboard fuels and other resources must be used to maintain proper spacecraft alignment so that sensors and antennas work properly.

The Ascent Solar Solution – Ascent Solar believes that a system-level solution is needed to provide space, near space and commercial and residential applications with better performing products than currently available. Ascent Solar has developed proprietary monolithically integrated processing techniques to take CIGS to production on high-temperature plastic substrate. These plastics can survive the manufacturing temperatures associated with thin-film CIGS processing while remaining flexible and electrically insulating. The insulating features of the plastics make it possible to connect individual cells into modules during processing. These advances in CIGS processing significantly reduce the weight, cost, and complexity of PV products – making this latest technology uniquely suited for high volume and low cost for space, near space and commercial and residential applications.

Through close interaction with ‘early adopters‘ and established prime contractors in the space, near space and commercial and residential building markets, Ascent Solar plans to develop a powerful solution that provides a system-level advantage over traditional technologies and other thin-film vendors. By combining its new manufacturing facility (currently under construction) with over a decade’s worth of R&D in this area, the company moves closer to its long term vision: to lead the emergence and acceptance of thin-film photovoltaics in the space and near-space industries and provide affordable solutions for clean energy that makes Building Integrated PV products as pervasive on rooftops and siding as materials like plywood are today.

(Play video to watch how our Flexible Photovoltaic Module is manufactured)