A thin-film field-effect transistor is formed by forming a dielectric layer adjacent a gate, forming a source region and a drain region, and forming a semiconductor layer on the dielectric layer. The semiconductor layer is deposited by spray pyrolysis and comprises a material selected from a group comprising: oxides; oxide-based materials; mixed oxides; metallic type oxides; group I-IV, II-VI, III-VI, IV-VI, V-VI and VIII-VI binary chalcogenides; and group I-II-VI, II-II-VI, II-III-VI, II-VI-VI and V-II-VI ternary chalcogenides.