Monday, 9 September 2024 9:00am – 10:00am

This seminar will be delivered in Norman Gregg Lecture Theatre – Edward Ford Building

Speaker: Professor Benjamin J. Schwartz

Host: Prof. Ivan Kassal

Title: The Roles of the Counterion and Morphology in Doped Conjugated Polymer Carrier Transport

Abstract: Conjugated polymers are intriguing materials, exhibiting the electrical properties of semiconductors while offering the advantages of flexibility and solution-processability for a wide range of devices.  Despite these advantages, however, semiconducting polymers face challenges due to their low intrinsic charge carrier density and semicrystalline nature, which can lead to poor charge transport characteristics. To improve the electrical properties of these materials, they can be doped with strong oxidizing or reducing agents, which creates carriers but also introduces counterions into the film.  The presence of counterions can significantly change the morphology of a conjugated polymer film, affecting carrier mobility.  Moreover, the coulomb interaction between counterions and carriers can create barriers for carrier motion, leading to significant complexity in how dopants affect the electrical properties of conjugated polymer films.  In this talk, we discuss several recent studies aimed at unraveling this complexity.  We use a series a novel dopants designed to minimize the coulomb interaction between counterions and carriers, as well as structural, optical and electrical studies to build a detailed picture of how doping affects the molecular properties of conjugated polymers.  All of this work has implications for the potential use of these materials in thermoelectric devices.

This is a companion seminar to the Hush Lecture which will be taking place on 13^th September 2024. For more information about the Hush Lecture, please see our brochure.