Metal chalcogenide films comprising at least one transition metal chalcogenide are prepared by dissolving a metal chalcogenide containing at least one transition metal chalcogenide in a hydrazine compound and, optionally, an excess of chalcogen to provide a precursor of the metal chalcogenide; applying a solution of said precursor onto a substrate to produce a film of said precursor; and annealing the film of the precursor to produce the metal chalcogenide film comprising at least one transition metal chalcogenide. The process can be used to prepare field-effect transistors and photovoltaic devices.