ZSW sets new thin film solar world record with 22.6% efficient CIGS PV cell


Germany’s Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) announced today that it has set a new world record for thin film solar technology with a 22.6% efficient solar PV cell based on copper indium gallium diselenide (CIGS) technology. The efficiency was verified by the Fraunhofer Institute for Solar Energy Systems (ISE).

Solexel has achieved higher efficiency for CIGS under concentrated sunlight, however this is the highest efficiency achieved to date under regular sun levels. This is the fifth world record that ZSW has set with CIGS, and beats the previous record set by Japanese PV maker Solar Frontier by 0.3%.

ZSW achieved the 22.6% efficiency on a 0.5 square centimeter test cell at a coating plant using co-evaporation. This cell represents a 0.6% gain from ZSW’s last record, and the organization notes that it has improved processes at several points, including the post-deposition treatment of the CIGS surface with alkaline metal compounds.

ZSW also notes that efficiency improvements with CIGS are rapidly building momentum. From 1998 to 2013 efficiency records increased 0.1% per year on average, however in the last three years this has increased to 0.7% annually.

But while the core technology booms CIGS has shrunk to a tiny share of the global market, and commercial-scale production is increasingly limited to fewer companies. A number of CIGS makers went out of business during the industry downturn, and Solar Frontier currently dominates the space with around 1 GW of annual production.

Three of the most promising CIGS makers, Global Solar Energy, MiaSolé and Solibro, were purchased by China’s Hanergy in 2013. However since the implosion of Hanergy’s financial position a year ago their fates remain unclear.