Preparation, structure, and electric properties of plasma-polymerized titanium-containing organic thin films

Abstract

Polymeric thin films were prepared from gaseous titanium tetraisopropoxide by low-temperature plasma polymerization. The films exhibited n-type semiconductor properties and showed conductivities in the range between 10−8–102 s/cm. High photocurrent under irradiation of 30 mW/cm2 of visible light was observed which exceeded the value found for plasma-polymerized copper acetylacetonate thin films by nearly three orders of magnitude. From x-ray photoelectron spectroscopy analysis, it was found that the films largely consist of metallic and organic layers corresponding to TiOx(0<x<2) and (CH2)n, respectively. Transmission electron micrograph observations and electron diffraction measurements made it possible to conclude that the film has a specific texture consisting of amorphous metal layers with an average thickness of 15–25 nm inside a polymer matrix.