Indium tin oxide (ITO) thin films, with/without poly(ethylene glycol) (PEG) additive, were deposited on either glass or oxidized silicon substrates by a sol-gel process. How the morphological, structural, optical, and electrical properties of the resulting ITO films changed with different processing parameters (heat treatment temperature and processing time), were investigated. Xray diffraction (XRD) results showed that the introduction of PEG lowered the intensity peaks as compared to those from the undoped ones. SEM and AFM investigations indicated that the PEG-doped thin films also result in a flatter surface compared to the undoped. Electrical and optical testing revealed that the doping of PEG could lead to an increased optical transmittance rate (~3-5%) for wavelengths 350-700 nm and a decreased sheet resistance. The ITO thin films prepared at low temperature has been employed as a gas-sensitive material for poisonous gas detection.

Keywords: sol-gel, PEG doping, optical properties, electrical properties, indium tin oxide