SCANNING TUNNELING MICROSCOPY EVIDENCE OF SEMICRYSTALLINE AND HELICAL CONDUCTING POLYMER STRUCTURES

Scanning tunneling microscopy images of strands, microislands, and thin films formed by the conducting polymers polypyrrole tosylate, polypyrrole tetrafluoroborate, and polythiophene tetrafluoroborate are presented. The polymer strands and microislands contain two types of helical structures with diameters of 1.5-1.8 nm, a simple helix, and 5-6 nm, a superhelix. The polymer films gradually transform from an ordered crystalline array located at the anode surface to an amorphous material at the air-polymer interface. © 1990 American Chemical Society.