Electrical properties of composites of TiO2-triphenylamine derivatives

We report a concept of organic molecular charge dopant in organic-inorganic composites and study its effect on the composite conductivity. Thin film composites are prepared from a 1:1 dispersion of TiO2 or other metal oxide particles in a polymer binder. Introduction of a small percentage of triphenylamine (TPA) derivative dopants increases the dark conductivity by up to five orders of magnitude. This phenomenon is explained in terms of electron donation by the dopant to a continuous network of aggregated metal oxide particles.