AFM Phase Imaging of Electropolymerized Polybithiophene Films at Different Stages of Their Growth

Abstract

The degree of crystallinity in electronically conducting polymers can affect a variety of important properties such as the work function, conductivity, and charge mobility. In our previous work (O'Neil, K. D.; Shaw, B.; Semenikhin, O. A. J. Phys. Chem. B 2007, 111, 9253), we studied the distribution of the local conductivity and doping level of conducting polymers with nanometer resolution using Kelvin probe microscopy (KFM) and current-sensing atomic force microscopy (CS-AFM). An unambiguous correlation was found between the polymer morphology, the local oxidation degree (related to the work function), and the local conductivity. One of the possible explanations leading to this behavior was a variation in the crystallinity of polymer films during their nucleation and growth. In this work, direct measurements of the local crystallinity of a conducting polymer, polybithiophene, are performed at different stages of the electropolymerization process using phase imaging atomic force microscopy (AFM). It was f...