IODINE EFFECT ON THE PROPERTIES OF POLY(N -VINYLCARBAZOLE) THIN-FILMSOBTAINED BY THERMAL EVAPORATION FROM A PRE-DOPED POWER

The effects of iodine on the structural and electrical properties of p oly-N-vinycarbazole (PVK) thin films obtained by thermal evaporation o f a iodine doped powder have been studied by scanning electron microsc opy (SEM), thermogravimetry (TGA), visible and infra-red absorption, X -ray photoelectron spectroscopy and I-V measurements. The morphologies of the pure PVK films and of the doped films are very different. Pure PVK films are homogeneous while iodine doped films are not (there is a lot of pin holes, grain boundaries...). Iodine is homogeneously dist ributed in the films in the I; configuration. The I-V plots of pure PV K layers are ohmics. In the case of Iodine doped layers, when E < 2,4. 10(5) V.m(-1), the I-V plots are ohmics, while the electrical conducti vity is controlled by Poole-Frenkel effect at higher voltage.