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 io dine-doped poly(N-vinylcarbazole) (PVK) as a function of annealing tre atment was performed. When doped at room temperature as at 370 K, the appearance of an ESR signal and the increase of the conductivity can b e explained by CT complex formation between iodine and PVK. The correl ation between conductivity sigma and spin density N-s was observed as a function of the annealing temperature. At higher annealing temperatu re, the decrease of the conductivity and of the ESR signal is attribut ed to the PVK degradation and to the formation of a new conjugated pol ymer. All these results and their discussion are in good agreement wit h X-ray diffraction, Raman diffusion, and earlier studies. (C) 1996 Jo hn Wiley & Sons, Inc.