Low Electrically Resistive Transparent Indium-Tin-Oxide Epitaxial Film on (001) Surface of YSZ by Pulsed Laser Deposition

High quality ITO thin films were grown hetero-epitaxially on extremely flat substrate of (001) YSZ by a pulsed laser deposition technique at a substrate temperature of 600°C. The crystal orientation relationship between the film and YSZ were confirmed as ITO (001) // YSZ (001) and ITO (010) // YSZ (010), respectively, by HR-XRD and HR-TEM. The carrier densities of the films were almost equal to Sn02 concentration in the films. That is, almost all the doped Sn4+ ions were activated to release electrons to the conduction band. The carrier densities of the films were enhanced up to 1.9×1021cm−3, while the Hall mobility showed a slight, almost linear, decrease from 55 to 40cm2V−1s−1 with increasing SnO2 concentration. The low resistivity is due to larger electron mobility, which most likely resulted from good crystal quality of the films. The optical transmissivity of the film exceeded 85% at wavelengths from 340 to 780nm.