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

Abstract

Iodine has been used to dope semi-conductive polymers in thin films form; one organic, the poly( N-vinylcarbazole), one inorganic, the selenium. When iodine doped powders are used to obtain the a-films (ante-doped films), the heating necessary to evaporate the powders induces some partial polymers degradation with unstable compound formation. After deposition, these compounds re-evaporate from the substrates forming pinholes and empty paths, which destroy the homogeneity of the films and damage their properties. These annoyances 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 decomposition more iodine is present in the films; these are more homogenous, which allows optimum conductivity properties.