(Invited) Thermoelectric Energy Conversion and Thermal Memristance and Switching

Abstract

Heat and charge are fundamental energy carrying modes relevant to nearly all dynamic properties of interest in engineering, physics, and modern energy technologies. Here, I will discuss the design and understanding of transport properties in complex nanoscale systems where the dimensional constraints are changed systematically to reveal fundamental principles of heat and charge transport. The first part of this talk will focus on heat and charge transport in polymeric and hybrid nanomaterials, revealing the physical origins of scaling laws for charge transport in these materials. The second portion of my talk will discuss heat and charge transport in a different class of hybrid materials, the ever-popular perovskites. Here, I will briefly discuss possible origins for the ultra-low thermal conductivity observed in nanoscale samples, and new measurement approaches for resistive bulk perovskites. The final portion of my talk will briefly highlight strong deviations from the Wiedemann-Franz law in materials with electronic phase transitions, and possible applications of this phenomenology for novel devices exhibiting, for example, thermal rectification and thermal memristance. Selected references: 1. Organic electronics: one model to rule them all, Nature Materials (2017) 2. Polymer morphology dominates over energy-dependent scattering in inorganic-organic hybrid thermoelectrics, Nature Communications (2018) 3. Ultralow thermal conductivity in all inorganic halide perovskites, PNAS (2017) 4. Phonon dispersion lifetimes of organic-inorganic hybrid perovskite CH3NH3PbI3 from Inelastic X-ray scattering (2018, in review). 5. Anomalously low electronic thermal conductivity in metallic vanadium dioxide, Science (2017) 6. Solid-state thermal rectification and negative differential thermal resistance using junctions of phase transition materials, Phys. Rev. Applied (2018)