title: Superhydrophobic SAM Modified Electrodes for Enhanced Current Limiting Properties in Intrinsic Conducting Polymer Surge Protection Devices.
abstract: Surface interface engineering using superhydrophobic gold electrodes made with 1-dodecanethiol self-assembled monolayer (SAM) has been used to enhance the current limiting properties of novel surge protection devices based on the intrinsic conducting polymer, polyaniline doped with methanesulfonic acid. The resulting devices show significantly enhanced current limiting characteristics, including current saturation, foldback, and negative differential effects. We show how SAM modification changes the morphology of the polymer film directly adjacent to the electrodes, leading to the formation of an interfacial compact thin film that lowers the contact resistance at the Au-polymer interface. We attribute the enhanced current limiting properties of the devices to a combination of lower contact resistance and increased Joule heating within this interface region which during a current surge produces a current blocking resistive barrier due to a thermally induced dedoping effect caused by the rapid diffusion of moisture away from this region. The effect is exacerbated at higher applied voltages as the higher temperature leads to stronger depletion of charge carriers in this region, resulting in a negative differential resistance effect.
authors.affiliation: †Department of Physics and Mathematics, University of Hull, Hull, United Kingdom HU6 7RX.|∥Electrical Engineering, International College of Engineering, University Kuala Lumpur, British Malaysian Institute, 53100 Kuala Lumpur, Malaysia.
authors.forename: Noor H
authors.initials: NH
authors.lastname: Jabarullah
authors.affiliation: †Department of Physics and Mathematics, University of Hull, Hull, United Kingdom HU6 7RX.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Verrelli
authors.affiliation: ‡TE Connectivity, Menlo Park, California 94025, United States.
authors.forename: Clayton
authors.initials: C
authors.lastname: Mauldin
authors.affiliation: ‡TE Connectivity, Menlo Park, California 94025, United States.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Navarro
authors.affiliation: ‡TE Connectivity, Menlo Park, California 94025, United States.
authors.forename: Josh H
authors.initials: JH
authors.lastname: Golden
authors.affiliation: §Department of Physics, National Technical University of Athens, 15780 Zografou, Greece.
authors.forename: Leonidas M
authors.initials: LM
authors.lastname: Madianos
authors.affiliation: †Department of Physics and Mathematics, University of Hull, Hull, United Kingdom HU6 7RX.
authors.forename: Neil T
authors.initials: NT
authors.lastname: Kemp