Preparation and characterization of spray deposited photoactive Sb2S3 and Sb2Se3 thin films using aqueous and non-aqueous media

Thin chalcogenide films of antimony have been attracting a great deal of attention because of their some special applications in optoelectronic devices and solar cells. The Sb2S3 and Sb2Se3 thin films have been prepared by a spray pyrolysis technique at their optimized conditions of substrate temperature and solution concentrations from the aqueous and non-aqueous media. The studies reveal that the films prepared from aqueous medium are amorphous and those obtained from non-aqueous medium are polycrystalline; especially the Sb2Se3 prepared from non-aqueous become polycrystalline after annealing. The optical absorption studies show the values of optical gap to be 1.1 and 1.28 eV, respectively, for Sb2S3 and Sb2Se3 for the aqueous medium while the same materials have direct band gap energies of 1.8 and 2.14 eV, respectively, when prepared from non-aqueous medium. When heated in nitrogen atmosphere for 2 h at optimized annealing temperature, the films of Sb2S3 and Sb2Se3 remain amorphous but those obtained from non-aqueous medium show enhancement in the crystallinity. The electrical resistivity for both films studied in the temperature range 300–500 K shows that the resistively is of the order of 106–107 Ω cm. The Sb2S3 and Sb2Se3, irrespective of preparation medium, are found to be n- and p-type, respectively. Both the materials are found to be photoactive when used in photoelectrochemical solar cells.