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 CuInS2 films, novel deposition technologies for CuGaSe2 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 CuInS2 two important results were achieved. The efficiency of Cu-poor CuInS2 cells could be increased to 8.3%. Standard Cu-rich prepared devices led to a new record efficiency of 12.5%.