Collaborative Research: RUI: Effects of Interfacial Properties on Charge Transport in Conducting Organic/Inorganic Composites

University Of Portland, Portland OR

Investigators

Abstract

Non-technical Description Organic semiconductors are used in many applications, such as light-emitting diodes, solar cells, and flexible electronics. They also have shown promise for new technologies such as converting heat into electricity and energy storage. In order to realize their potential, it is necessary to better understand charge transport. This interdisciplinary project will study how electrical charge moves through composites of conducting polymers and nanoparticles. The focus is on controlling charge transport across interfaces to create materials that are useful for clean energy technologies. This collaborative project will be performed at two primarily undergraduate institutions. While achieving the technical goals of the project, the investigators will also educate the next generation of scientists in energy conversion and storage concepts and techniques. The project uses scalable earth-abundant materials and low-cost solution-based manufacturing approaches. This will facilitate the widespread deployment of technologies that make use of these composite materials. Technical Description This study enhances understanding of the physicochemical properties of the interface between components of a nanostructured conducting organic/inorganic composite and their influence on its charge transport, by exploring the role of an interfacial term on models of charge transport and experimentally testing those models. In particular, this interfacial term illuminates the emergence of composite transport phenomena that transcend the sum of the individual components. Previous models of electronic transport in these materials generally neglect interfacial effects by using an effective-medium approximation to treat the interpenetrating material as a combination of individual parallel and series phases. By incorporating the impacts of interfacial area, thickness, and interfacial energy barrier, this project guides the design of such materials for many applications, with a specific focus on these materials’ thermoelectric energy conversion and capacitive energy storage. At both Reed College and University of Portland, undergraduate students will be involved in all aspects of research, from initial laboratory setup and theoretical modeling to data analysis, presenting results, and writing papers. By design, this project uses straightforward solution-based fabrication and experimental techniques, which makes it particularly accessible to students who may be new to research and/or newly forming their identities as scientists. This project directly involves undergraduate students in research and will indirectly impact many others through improved research infrastructure, updated laboratory curriculum, and new opportunities for undergraduate thesis projects. It additionally links fundamental scientific understanding, both experimental and theoretical, with the engineering of technologies that are crucial for the future of our society. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.