2022

Dr. Natsumi Komatsu (Rice University)

  • Title: Thermoelectric and Electronic Transport Studies of Ultrahigh-Conductivity Carbon Nanotube Fibers
  • Date: 2022.5.25 (Wed) 9:30-10:30
  • Place: 14棟7階フォーラム
  • Abstract: Ever since the discovery of carbon nanotubes (CNTs), it has long been a challenging goal to create macroscopically ordered assemblies, or crystals, of CNTs that preserve the extraordinary properties of individual CNTs on macroscopic fibers of aligned CNTs with ultrahigh electrical conductivity have been successfully fabricated, but their transport properties and mechanisms have not been systematically investigated. We first studied their electronic transport properties, and found the aligned CNT fiber to be in the weak localization regime at low temperatures, in contrast to all previously studied CNT assemblies, whose low-temperature transport behaviors were described by hopping carriers in strongly localized regimes. Indeed, we observed the phenomenon of universal conductance fluctuations, which is a hallmark of quantum coherent transport, in bundles that constitute the fibers at low temperatures. We further found a series of exceptional properties for the aligned CNT fibers: high continuous current rating, a thermal conductivity comparable to copper, and the largest thermoelectric power factor ever achieved for any CNT sample. These findings will lead to deeper understanding of dominant electronic transport mechanisms inside the fibers, and also provide a route for new opportunities for electrical, thermal, and thermoelectric applications.
  • Bio: Natsumi Komatsu received a B.S. degree from Keio University, and received an M.S. degree and Ph.D. degree from Rice University. Her research interests include developing macroscopically aligned carbon nanotubes and investigating their electrical, thermal, optical, and thermoelectric properties. During her PhD at Rice, she served as a graduate student ambassador as well as a Grad STRIVE liaison. She is an alumna of two TOMODACHI programs and Funai Overseas Scholarship.
  • Organizer: Tomoko Shimizu