Jonathan Rivnay1
Northwestern University1
Organic mixed ionic-electronic conductors (OMIECs) have gained considerable interest in bioelectronics, power electronics, circuits and neuromorphic computing. These organic, often polymer-based semiconductors rely on a combination of ionic transport, electronic transport, and high volumetric charge storage capacity. Despite recent progress and a rapidly expanding library of new materials, a full understanding of fundamental processes of OMIECs remains largely unexplored. Critically, useful studies require us to probe these systems in device-relevant conditions, fully considering the effects of ions and solvent on microstructure and transport. To this end, we report on recent efforts towards structure/composition-property relations in high performance organic mixed conductors using ex-situ, in-situ, and operando scattering and spectroscopic techniques. We use a combination of GIWAXS, GISAXS, XPCS, E-QCMd, UV-Vis, XRF, as well as device measurements to explore kinetics, composition, and structural evolution during electrochemical operation. Importantly, these findings provide insights into materials design for enhancing device performance and stability.