MIDSUMMER

Midsummer was founded in 2004 by people with a background from the optical disc manufacturing equipment and the photo mask industry. Midsummer has its head office in Stockholm, Sweden and has some of the most experienced CIGS researchers in Scandinavia. Thin film solar cells have long been considered as a promising technology for photovoltaics. Thin film CIGS solar cell technology has now been developed for almost 40 years. The technology has matured in the sense that several research groups ... have reached CIGS solar cell efficiencies over 20%. However, the transition from laboratory research to volume manufacturing has often proven quite hard. Many CIGS companies have ceased operations due to either lack of technical success or difficulties to reach profitability. In many cases, promising laboratory scale results have proven difficult to transfer to large scale volume production at a competitive cost. Midsummer, has taken a different route from the start as Midsummer’s founders have their background from the optical disc industry, making production equipment for CD and DVD manufacturing. This mature technology we decided to use for the production of CIGS thin film solar cells. As the technology relies on simultaneous parallel processing of several small area substrates, Midsummer makes 156×156 mm CIGS cells which are interconnected into modules in the same manner as silicon solar cells. By making cells, instead of large area modules, we have been able to do all our process development on 156×156 substrates and thereby avoid any upscaling issues. As the substrates are made of 0.15 mm thin ferritic stainless steel, they are flexible and can be used for lightweight flexible modules.More