Sweden-based Midsummer, a supplier of production lines for manufacturing of flexible thin-film copper indium gallium di-selenide (CIGS) solar cells, has developed a high speed process for manufacturing such cells that uses sputtering for all layers in the solar cell structure. Midsummer says it has achieved 15% active area efficiency on an entire 225 square-centimeter solar cell using its DUO machine employing this technology.
Midsummer says that by using sputtering in all processing steps, the cycles in the manufacturing of solar cells can be shortened and also be made cadmium-free. The process works for stainless steel substrates that are suitable for flexible modules. The company says this approach enables manufacturers to produce thin-film CIGS cells with high efficiencies.
Moreover, Midsummer says its process is a completely dry and all-vacuum one, enabling manufacturing with less stringent clean-room requirements.
Sven LindstrÃ¶m, CEO of Midsummer, says the company's process makes it possible to manufacture thin-film CIGS solar cells fast, efficiently and cost effectively even in small volumes. He also says that stainless steel substrates are suitable not only for regular solar panels, but also for flexible, lightweight panels that can be used on membrane roofs, landfills or other structures where traditional glass modules cannot be applied.