Preparation and characterization of plasma-polymerized thiophene films

Plasma polymerization of thiophene was carried out in a tubular reactor using an rf source. Various substrates such as aluminum, glass, and NaCl crystal were used. The rate of deposition attained an equilibrium value of 0.35 mu g cm(-2) s(-1). Infrared spectra revealed the formation of polythiophene. The films were found to be highly crosslinked. The electrical conductivity was found to be very low (10(-15)-10(-10) S/cm). The mode of electrical conduction was found to be space charge-limited current. SEM studies showed that the films consist of globules, the size of which varied from 1 to 10 mu depending on the time of deposition. X-ray diffraction studies revealed the films to be highly amorphous. (C) 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 203-209, 1998.