The invention relates to a preparation process for thin semiconducting inorganic films comprising two or more metals (Cu/ln/Zn/Ga/Sn), selenium and/or sulfur. The process uses molecular metal-containing precursor complexes with organic S/Se/Te-containing ligands in combination with one or more precursors of a second metal which are free of S/Se/Te. Copper- based chalcopyrites of the l-lll-VI2 -type are prepared with high purity at low temperatures in air or inert atmosphere. The thin films can be used in photovoltaic panels (solar cells).
