In situ AFM study of the electrochemical deposition of polybithiophene from propylene carbonate solution

Abstract

Early stages of galvanostatic deposition of polybithiophene onto highly oriented pyrolytic graphite (HOPG) from propylene carbonate solution were investigated using electrochemical atomic force microscopy (ECAFM). The polymer film thickness was evaluated in situ using surface modification with the AFM tip and was found to be proportional to the grafting charge Q and independent of the deposition current density i in the current density range from 0.1 mA/cm 2 to 2 mA/cm 2. The first stage of the deposition was the formation of polymer nuclei with an average height of ca. 1 nm; continuous film was formed at Q≥0.5 mC/cm 2. Even at the earliest stages, the polymer featured grain structure with the average grain size of ca. 50 nm. The presence of the crystalline phase in the films was demonstrated by the X-ray diffraction data.