Formation of polythiophene multilayers on solid surfaces by covalent molecular assembly

In this work, we demonstrate the deposition of multilayers of conducting polythiophene films on different substrates with substrate-film and layer-to-layer links established by covalent bonding. The films were characterized by UV–Visible spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and ellipsometry. Thickness of the films and UV–Visible absorption intensity increased linearly with increase in the number of layers. The covalently bonded nanostructure films possessed uniformity, good thermal and chemical stabilities. Electrochemical impedance spectroscopy confirmed uniform coverage of the substrate by the films and improvement of the electrical characteristics of the films after doping. The technique facilitates formation of robust, functional ultrathin films for use in chemical sensing and photovoltaic applications.