Deposition by laser ablation and characterization of titanium dioxide films on polyethylene-terephthalate

Thin titanium dioxide films have been deposited on polyethylene-terephthalate (PET) by laser ablation deposition technique. The experiments were performed with a quadrupled Nd:YAG laser (266 nm) and an ArF excimer laser (193 nm), at room temperature and without any oxygen addition during the ablation. The as-prepared films have been characterized by various techniques: Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), X-Ray Microprobe, Laser Microprobe Mass Spectrometry (LMMS), and ellipsometry. For this last technique the titanium dioxide films were deposited onto a silicon substrate. The thicknesses of the films are ranging between 100 and 150 nm. Their surfaces are smooth and the presence of some holes (diameter <1 μm) and of some particles can be noticed. The films are amorphous and non-stoichiometric. Their electrical resistivity of about 1 ω · cm at room temperature is indicative of a semiconductor material behaviour.