Synthesis and characterization of indium-tin-oxide particles prepared using sol-gel and solvothermal methods and their conductivities after fixation on polyethyleneterephthalate films

The focus of this study was on the physical properties of two types of indium-tin-oxide particles prepared via sol-gel and solvothermal methods. The In2O3 was shown to have a cubic structure from the X-ray diffraction patterns obtained after annealing of the particles prepared via the sol-gel and solvothermal methods at 1200 and 600 degrees C, respectively. The average particle size was measured using high-resolution transmission and scanning electron microscopies. The indium-tin-oxide particle sizes prepared using the solvothermal and sol-gel methods were within the ranges 10 to 30 nm and 30 to 50 run, respectively. The surface charges of the sol-gel and solvothermally obtained annealed indium-tin-oxide particles in ethanol solution were +28 and +40, respectively, indicating that the latter were more stable. X-ray photon spectroscopy showed that the In ions in the solvothermally prepared indium-tin-oxide were more oxidized than those prepared using the sol-gel method. These indium-tin-oxide particles were fixed onto polyethylene terephthalate films using a silicon binder. The conductivity of the solvothermally prepared indium-tin-oxide/polyethylene terephthalate films was higher than that prepared by the sol-gel method: the resistance of the solvothermally prepared indium-tin-oxide (after annealing at 600 degrees C)/polyethylene terephthalate film was 2.0 x 10(4) Omega per square, but 5.0 x 10(4) Omega per square for that prepared via the sol-gel method. (C) 2007 Elsevier B.V. All rights reserved.