Towards low-cost, environmentally friendly printed chalcopyrite and kesterite solar cells

Solution-processed organic and inorganic semiconductors offer a promising path towards low-cost mass production of solar cells. Among the various material systems, solution processing of multicomponent inorganic semiconductors offers considerable promise due to their excellent electronic properties and superior photo-and thermal stability. This review surveys the recent developments of all solution-processed copper-indium (-gallium)-chalcogenide (CuInS2, CuInSe2 and Cu(In, Ga)(Se, S)(2)) chalcopyrites and copper-zinc-tin-chalcogenide (Cu2ZnSnS4 and Cu2ZnSnSe4 (CZTS(e))) kesterite solar cells. A brief overview further addresses some of the most critical material aspects and associated loss mechanisms in chalcopyrite and kesterite devices. Today's state-of-the- art performance as well as future challenges to achieve low-cost and environmentally friendly production is discussed.