Polycarbazole obtained by electrochemical polymerization of monomers either in solution or in thin film form

Polycarbazole has been synthesized by electrochemistry. The carbazole monom er source consists either in carbazole in solution in the electrolyte or in carbazole deposited in thin film form onto the working electrode. The two families of polymers have been studied by infrared absorption, X-ray diffra ction, thermal gravimetric analysis, scanning electron microscopy (SEM), X- ray photoelectron spectroscopy, electron spin resonance, and electrical con ductivity measurements. It is shown that the polycarbazole films obtained w ith carbazole deposited in the thin film form exhibit a better polymerizati on efficiency and an electrical conductivity one order of magnitude higher. This result is in good accordance with a higher spin density and homogenei ty. It is proposed that not only are some monomers activated during the eva poration but also that the physical contact between the working electrode a nd the continuous carbazole films induces the growth of homogenous highly p olymerized polycarbazole films. In agreement with this suggestion, the SEM study shows that this type of polycarbazole thin films keep in memory the m orphology of the SnO2 under layer. (C) 2000 John Wiley & Sons, Inc.