Microscopical Investigations of PEDOT:PSS Thin Films

Electron microscopy studies are used to explore the morphology of thin poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate acid (PEDOT PSS) films. The figures show that the films are composed of grains with diameters in the range of about 50 nm. Energy dispersive X-ray spectroscopy analysis reveals that individual grains have a PEDOT-rich core and a PSS-rich shell with a thickness of about 5-10 nm. Atomic force microscopy (AFM) is then used to analyze the topography of fracture surfaces of ruptured PEDOT PSS tensile specimens. These AFM scans also show that the films are composed of grains dispersed in a matrix. The investigations presented herein yield a picture of PEDOT PSS morphology with unprecedented clarity.