Study of conducting ITO thin film deposition on flexible polyimide substrate using spray pyrolysis

Nanostructured indium tin oxide (ITO) thin films have been grown by chemical spray pyrolysis method on flexible polyimide (PI) polymeric substrates at various temperatures (400, 450 and 500 C) using solutions of indium and tin chlorides as precursors. The composition, microstructure, surface morphology, thermal, electrical, and optical characteristics have been analysed by FT-IR, UV–Vis, X-ray diffraction, SEM, EDAX, atomic force microscopy, electrical measurements, TGA, etc. X-ray diffraction measurements employing Cu-Ka radiation showed that the ITO films were polycrystalline with a cubic bixbyite structure. An increment in average grain size, electrical conductivity and optical transmittance was observed at higher substrate temperature. ITO-coated films maintained the mechanical properties and stability of the pristine PI films. The adhesion between surface ITO layers and PI matrix was found acceptable.