Intrinsic conducting polymers are key components in organic electronic devices. These materials are also known to be sensitive toward a variety of gases and vapors, which can be exploited by incorporation as chemical sensitive element in a nanoscale sensing system. The molecular interaction between the gas species and polymer layer leads to a change in the electrical properties and the electronic state of the organic semiconductor (e.g., conductivity, workfunction, doping level). In this study, examples are given how to tune electronic properties of organic semiconductors, and how this can influence the nature of electrical contacts of active chemical sensitive elements in organic electronic devices used as chemical gas sensors. The present work is focused on polypyrrole-based junction controlled electronic devices, such as Schottky barrier diodes, using different metal phthalocyanines as molecular chemical sensitive compounds.
Purdue University, West Lafayette, IN