The incorporation of various additional constituents into I-III-VI2-based chalcopyrite absorber layers in particular the introduction of Ag into Cu(InGa)Se2 to form (AgCu)(InGa)Se2 absorber layers may be used as a means of increasing open-circuit voltage reducing processing temperature and/or improving device performance without otherwise modifying the absorber layer or device fabrication processes.
1) The invention allows the achievement of higher photovoltaic conversion efficiency via higher open-circuit voltage short-circuit current and fill factor. 2) It may also be utilized to lower substrate processing temperatures in the manufacture of solar power modules thereby more readily allowing the use of substrates such as plastic films which have advantages over other substrates such as metal foils and glass. 3) It further potentially enables other manufacturing techniques which so far have not proven successful.