Dielectric properties of pulsed-laser deposited indium tin oxide thin films

Polycrystalline tin-doped indium oxide (ITO) thin films were prepared by Pulsed Laser Deposition with an ITO (In2O3-10 wt.% SnO2) ceramic target and deposited on transparent borosilicate glass substrates between room temperature (RT) and 400 °C. The RT grown specimen was structurally investigated by Transmission Electron Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy and X-Ray Diffraction. It contained both amorphous and crystalline phases. The electro-optical properties of the RT-grown sample were almost similar to those of the samples grown at higher temperatures. Finally, Scanning Transmission Electron Microscopy–Valence Electron Energy Loss Spectroscopy was used to derive locally dielectric properties which were compared with ellipsometry measurements in the 1.5–5.5 eV range using a Tauc–Lorentz model.

► Indium tin oxide thin films contained both amorphous and crystalline phases.
► Dielectric properties were derived both at the nanoscale and macroscale.
► Nanoscale and macroscale measurements agreed in the predominant amorphous phase.