Phonon transport manipulation and control in graphene for energy applications

Graphene has attracted significant attention due to its extraordinary electronic and thermal properties and the great application potential in nanoelectronics and renewable energy harvesting/conversion. This talk will cover the experimental and theoretical work that has been conducted in the Micro/Nanoscale Thermal Science Laboratory at ISU on phonon energy transport in graphene and novel approaches to manipulating/tailoring it to meet the need in energy applications. For phonon transport, the research is focused on the dynamic transient response of graphene to thermal impulse to reveal the phonon energy coupling and the distinctive behavior of the three phonon modes in transferring energy. For graphene applications, the phonon behavior across the structure-bent area is studied in detail to reveal the local mode- conservation and evaluate the local bending resistance. The energy transport in graphene- substrate interfaces is studied by combined experiment and modeling to understand the local energy dissipation that will be involved in graphene-based nanoelectronics. Our most recent work has made two new discoveries about energy manipulation in graphene: 1) the phonon energy can be inversed mode-wide to achieve energy separation, conversion, and ps-scale energy storage, 2) through careful phonon manipulation, graphene can conduct heat in two opposite directions simultaneously, proposing a novel way for energy conversion in space.