Influence of the iodine doping process on the properties of organic and inorganic polymer thin films

Iodine has been used to dope semi-conductive polymers in thin films form; o ne organic, the poly(N-vinylcarbazole), one inorganic, the selenium. When i odine doped powders are used to obtain the a-films (ante-doped films), the heating necessary to evaporate the powders induces some partial polymers de gradation with unstable compound formation. After deposition, these compoun ds re-evaporate from the substrates forming pinholes and empty paths, which destroy the homogeneity of the films and damage their properties. These an noyances can be avoided when the films are deposited from pure powders and post-doped. It is shown that when the films are iodine doped after decompos ition more iodine is present in the films; these are more homogenous, which allows optimum conductivity properties. (C) 1999 Elsevier Science Ltd. All rights reserved.