Kesterite tech news
GCL Technology Holdings Limited (HKG: 3800) announced on May 21, 2026, the successful integration of a Kesterite (CZTS) buffer layer into its commercial--scale perovskite production line in Kunshan. This new "K--Passivation" technique utilizes earth--abundant copper, zinc, and tin to replace scarcer materials, significantly enhancing the moisture resistance and thermal stability of its perovskite--silicon tandem modules. The company reports that this material shift has achieved a certified aperture efficiency of 26.4% on a standard module format, while reducing the cost of the buffer layer by approximately 40%. GCL aims to leverage this breakthrough to accelerate the deployment of its "Indium--Free" high--efficiency modules for the utility--scale market by early 2027.