Kesterite tech news
Canadian Solar Inc. (NASDAQ: CSIQ) announced on August 22, 2026, the development of its "Bi--K" tandem cell technology, which pairs a Kesterite (CZTS) thin--film top cell with a high--efficiency N--type TOPCon bottom cell. This 4--terminal architecture achieved a record efficiency of 28.1% for Kesterite--based tandem structures. By utilizing earth--abundant materials for the top layer, Canadian Solar aims to provide a high--stability alternative to Perovskite--Silicon tandems, leveraging the inherent durability of the CZTS mineral structure. The company has initiated a pilot line to evaluate the scalability of the vacuum--based deposition process for the Kesterite layer, targeting a reduction in Levelized Cost of Energy (LCOE) for utility--scale deployments.