Surface characterizations of thin film coatings of carbazole containing random poly(carbazole-co-3-methylthiophene) P[Cz-co-3-MeTh] copolymers on carbon fiber were performed. Coatings with different initial feed ratios of comonomers were electrochemically formed (grafted) onto carbon fibers by constant current electrolysis. The resulting copolymers were characterised with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The characterization of the thin copolymer films was performed on the surface of the carbon fiber. This allows the relationship between the initial feed ratio of the comonomer, the resulting morphology and the surface structure of these thin film coatings to be investigated. The range of thickness increase (diameter) was from 200 nm to 6.74 mum depending on the polymer and copolymers used. (C) 2003 Elsevier B.V. All rights reserved.