Properties of chlorine-doped poly(N-vinylcarbazole) thin films

Abstract Thin films of poly( N -vinylcarbazole) (PVK) have been obtained by thermal evaporation under vacuum. The chain length of the polymer is shortened by this deposition technique, which induces a strong reactivity between chlorine and the PVK films. After chlorine doping, there is complex salt formation as shown by electron spin resonance spectroscopy (ESR) and X-ray photoelectron spectroscopy (XPS). However, the major part of the chlorine has reacted with PVK. The thermal evaporation induces amorphization of the PVK, while chlorine doping induces polymer degradation with NH 4 Cl formation. Because of this degradation the carriers detected by ESR are strongly localized on carbazole radicals, thereby explaining the small increase in the conductivity of PVK films even after chlorine doping.