Study of the evolution of the conductivity of iodine-doped poly(N-vinylcarbazole) as a function of annealing treatment

Electron spin resonance (ESR) and d.c. conductivity measurements on iodine-doped poly(N-vinylcarbazole) (PVK) as a function of annealing treatment was performed. When doped at room temperature as at 370 K, the appearance of an ESR signal and the increase of the conductivity can be explained by CT complex formation between iodine and PVK. The correlation between conductivity σ and spin density Ns was observed as a function of the annealing temperature. At higher annealing temperature, the decrease of the conductivity and of the ESR signal is attributed to the PVK degradation and to the formation of a new conjugated polymer. All these results and their discussion are in good agreement with X-ray diffraction, Raman diffusion, and earlier studies. © 1996 John Wiley & Sons, Inc.