Atomic force microscopy study of the morphology of polythiophene films grafted onto the surface of a Pt microelectrode array

This work involves the application of atomic force microscopy (AFM) to the study of the morphology of polythiophene (PT) films grafted onto an array of six-band microelectrodes used for the measurements of in situ electronic conductivity of polymeric films. The following two types of the polymeric film can be distinguished: one film is related to the layer just above the microelectrodes, whereas the other type of film bridges the gap between the two microelectrodes. We have shown that the gaps located in the interior part of the array are completely bridged by the PT film; however, the thickness of the film above the microelectrodes is about one order of magnitude larger than that related to the center of the gap. The Z-profile of the film across the gap has a rounded shape. The lateral (friction) force image taken from both types of the PT films shows that they are similar. The AFM images prove that the PT film possesses mainly a granular-type morphology.