Kesterite tech news
Researchers from the University of Bristol and Universitat Politècnica de Catalunya published a study in ACS Applied Materials & Interfaces on September 18, 2026, evaluating alkali post--deposition treatments (PDTs) on solution--processed silver--alloyed kesterite (ACZTSSe) solar cells. While alkali treatments are widely used in commercial chalcopyrite (CIGS) thin--film manufacturing to enhance performance, the team found that applying alkali fluorides (LiF, NaF, RbF, CsF) to kesterite absorbers led to performance degradation, dropping conversion efficiencies from a 12.20% baseline down to ~11% for light alkalis and triggering sharper losses in fill factor with heavier alkalis. Advanced surface analysis demonstrated that thermal processing during PDT induces substantial surface elemental disorder and widens work--function distribution, causing an open--circuit voltage deficit of up to 200 mV. These findings define critical processing boundaries for solar manufacturers adapting legacy thin--film passivation techniques to earth--abundant kesterite architectures.