Study of Thermal Transport, Dissipation and Internal Cooling in Nanoelectronic Systems
Abstract
Approved for public releaseEnergy dissipation and heat transport play a critical role in the operation of almost all nanoelectronicdevices. Specifically, the interactions of charged quasiparticles, such as electrons and holes, both among themselves and with other quasiparticles like phonons, lead to dissipation of energy and decoherence, and relaxation of non-equilibrium distributions. Further, novel transport properties with no counterparts in the bulk are expected to arise in nanoscale systems. In this work we seek to elucidate heat transfer in nanomaterials, such as graphene nanoribbons (GNRs), which are expected to feature a divergent thermal conductivity due to their quasi 1-D characteristics. Moreover, we seek to explore the novel energy dissipation and scattering characteristics that are expected to arise in nanoscale systems, which offer both opportunities and challenges for realizing quantum transport in 2-D materials and topologically protected systems. Further, we will explore local cooling and heat dissipation in nanoelectronic devices, such as tunneling field effect transistors and high electron mobility transistors, which strongly influence local temperature fields and device performance. Key to making rapid progress in understanding these systems is the development of experimental tools that enable, at cryogenic temperatures, direct measurements of extremely small heat currents (femtowatts and below) as well as record temperature fields with a spatial resolution of a few nanometers while measuring energy flow and generation with few eV/second (attowatt) resolution, i.e., the energy associated with making or breaking a few chemical bonds.In this project, we will employ novel microkelvin temperature-resolution and attowatt energy-resolution scanning probes to answer the following key questions: 1) Doesthe thermal conductivity of GNRs diverge as suggested by the Fermi-Ulam-Pasta theory due to non-ergodicity in 1-D chains? How do the thermal transport properties depend on the periodicity of the nanoribbons and the phononic band structure of these 2-D structures?2) How does the scattering of carriers with defects in 2-D materials result in dissipation and loss of coherence? In topological materials, how do carriers in topological edge and surface states interact with defects on the surfaces and within the bulk of a material? 3) What are the internal cooling properties of nanoelectronic devices operating in the diffusive and tunnel regimes? What are the limits to the internal cooling fluxes that can be achieved in such devices? How can internal cooling be achieved by taking advantage of energy filtering during tunneling? Would it be possible to dramatically enhance internal cooling in tunneling-based nanoelectronic devices?4) What controls the thermal boundary resistance multilayered nanoelectronic devices such as electron mobility transistors (HEMTs)? How can the operational temperature of such devices be dramatically reduced? Obtaining deep insights into the nature ofenergy dissipation and transport at the nanoscale can have tremendous positive impact on the development of low power electronics, high density memory and novel neuromorphic computing tools, which can transform internal monitoring systems for engines, air-launched weapons, and portable computing platforms for naval ships. Further, the tools that will be developed as part of this work can havea major impact on a number of fields, including condensed matter physics, materials science and chemistry and can enable the discovery and engineering of new materials that can benefit a number of technologies that the navy is interested in.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 08, 2024
- Source ID
- N000142412132
Entities
People
- Pramod Sangi Reddy
Organizations
- Board of Regents of the University of Michigan
- Office of Naval Research
- United States Navy