Structural, optical, morphological and electrical properties of indium oxide thin films prepared by sol gel spin coating process

Indium oxide (In2O3) thin films have been deposited by sol gel spin coating technique for different molar concentrations on glass substrates. X-ray diffraction spectra confirmed that the films have a polycrystalline nature with high preferred orientation along (222) plane corresponding to In2O3 cubic structure. Scanning electron microscope images show that the films have homogenous, uniform and dense surface without any pin holes and cracks. The Energy dispersive X-ray spectra confirm the presence of In and O elements in the deposited films. The optical analyses show that the films exhibit an optical transparency that reaches up to 90% in the visible range and optical band gap decreases from 4.04 to 3.88 eV. Photoluminescence spectra show mainly three emissions peaks (ultraviolet, blue and green), which decrease in the intensity with the raise of molar concentration. FTIR spectroscopy confirmed the presence of In–O and In–O–H absorption bands. Electrical measurements reveal that prepared films have a good conductivity (2.5 × 101 (Ω cm)−1).