Elaboration and characterization of undoped and doped indium oxide thin layers elaborated by sol gel process for photonic and photovoltaic applications

Abstract

Undoped indium oxide thin films have been deposited by sol-gel spin coating technique using indium (III) nitrate hydrate, absolute ethanol and acetyl acetone as precursor solution, solvent and stabilizer, respectively. The effects of the film thickness, pH solution and molar concentration precursors (indium III acetate anhydrous and indium III chloride anhydrous as precursor and acetyl acetone as solvent) on the structural, morphological, optical and electrical properties of In2O3 films have been studied. Doped indium oxide thin films have been deposited by sol-gel spin coating technique using indium (III) chloride anhydrous, absolute acetyl acetone as precursor solution and solvent, respectively. The effects of Sb doping and Ba doping on the structural, morphological, optical and electrical properties of In2O3 films have been studied. All films have been characterized by multiple techniques such as X-ray diffraction (XRD),UV-Visible spectroscopy, scanning electron microscope (SEM), and four probe method to investigate the physical properties of indium oxide films. X-ray diffraction analysis showed that the films are polycrystalline in nature having cubic crystal structure with preferred growth orientation along (222) plane. The growth of the films changed the direction from [111] to [100]. SEM images show that the films are homogenous, uniform and dense without any pin holes and cracks. The transmittance of In2O3 films was high up to 90%and it is probably related to the good crystalline quality of the films. The optical gap was found to vary between 2.95 and 3.23 eV. The electrical measurements revealed the resistivity have values about1.5×10-4– 1.7×10-2(Ω.cm) which made these films suitable for optoelectronic applications.