The Applications of Sol-Gel Derived Tin Oxide Thin Films

Transparent conducting SnO₂-based thin films have been coated on flat substrates such as fused quartz, and ceramic fiber cloths such as the Nextel and E-glass cloth from tin alkoxides by the sol-gel technique. Also, thin films of alternating layers of SnO₂ and SiO₂ have been fabricated by dip coating. The sheet resistance and average visible transmittance of the films were investigated in the aspect of the applications as transparent electrodes such as liquid crystal displays, photo-detectors and solar cells. The Nextel and E-glass cloths coated with antimony-doped tin oxide (ATO) had sheet resistance of as low as 20 ohm/□ and 120 ohm/□ , respectively. The promotion effects of additives as La₂O₃ and Pt on the ethanol gas sensing properties of the films were investigated in the aspects of the applications as an alcohol sensor and a breath alcohol checker. Possible evidence of quantum well effects in the oxide multilayers of SnO₂ and SiO₂ was investigated.