A Comprehensive Analysis of ITO:FeCl3 and ITO:AlCl3 Thin Films Obtained by the Sol–Gel Process

Abstract

The properties and applications of Ferric Chloride (FeCl₃) and Aluminum Chloride (AlCl₃) films made by the sol–gel technique are fully examined in this work. Its main objectives are these films’ synthesis, structural characterization, and performance assessment. Using a sol–gel dip-coating process, thin films of pure indium tin oxide (ITO) and ITO mixed with FeCl₃ and AlCl₃ at ratios of 50, 100, and 150% were produced. Indium (III) Chloride (InCl₃) and Trichlorostannate (SnCl₄) two reasonably priced precursors were used. X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), and ultraviolet–visible UV–Vis spectroscopy were utilized to examine the ITO samples. Whereas the gap in the optical band of pure ITO was 4.49 eV, the energy gaps for ITO mixed with FeCl₃ at 50, 100, and 150% were 2.61, 2.89, and 2.35 eV, respectively. The energy gaps for ITO combined with AlCl₃ at the same ratios were 1.73, 1.83, and 1.5 eV. In the XRD patterns of indium oxide, the (222) plane showed a large peak, signifying a high degree of crystallinity. Using AFM images, the average grain size of pure ITO was discovered to be 61 nm. The average grain sizes for AlCl₃ were 17, 21, and 68 nm, whereas the average grain sizes for FeCl₃ were 96, 36, and 178 nm at 50, 100, and 150% ratios, respectively. The FeCl₃-doped films’ average particle sizes were found to be 23.87, 41.12, and 36.27 nm, respectively, according to SEM images. The AlCl₃-doped films’ average particle sizes were 45.47, 42.72, and 35.25 nm. The water contact angles for FeCl₃ films were found to be 32.57° for pure FeCl₃ and 18.74°, 73.66°, and 43.98° for FeCl₃ at 50, 100, and 150% mixing ratios, respectively, according to the contact angle measurements. The water contact angles for AlCl₃ films were 65.39°, 85.99°, and 78.12° for 50, 100, and 150% of the mixing ratio, in that order.