Processes for chalcopyrite-based solar cells

Abstract This contribution deals with the investigations of chalcopyrite solar cells. Main attention is paid to absorber materials with band gaps larger than 1.5 eV. Besides the different efforts to modify and optimise stoichiometric CuInS 2 films, novel deposition technologies for CuGaSe 2 films and buffer layers as well as alternative buffer layers were studied and compared. With ZnSe as alternative buffer layer on Cu(InGa)(S,Se) 2 absorbers developed by SSI Camarillo and Siemens Solar, Munich, total area efficiencies up to 13.7% and active area efficiencies up to 15.7% could be reached, respectively. For CuInS 2 two important results were achieved. The efficiency of Cu-poor CuInS 2 cells could be increased to 8.3%. Standard Cu-rich prepared devices led to a new record efficiency of 12.5%.