Progress beyond state of the art

With the introduction of RbF (and CsF) post-deposition treatment (PDT) of CIGS absorbers, a step forward to even higher efficiencies could be made. Finally, using the RbF-PDT procedure combined with an advanced buffer system with very thin solution-grown CdS and sputtered (Zn,Mg)O, a certified cell efficiency of 22.6% (with anti-reflective coating) could be reached.