Nonlinear Electro-Thermal Transport in Metallic Carbon Nanotubes

We propose a model for the incoherent charge carrier transport in one-dimensional conductors based on the semi-classical Boltzmann transport equation. The electronic transport in these systems is described by treating independently the forward and backward carrier populations mutually coupled through interactions. In particular, we show that: (i) in the presence of elastic backscattering the Wiedemann-Franz law is restricted to each branch with its specific temperature and that (ii) the thermoelectric power vanishes due to electron-hole symmetry. The model provides an interpretation of the distribution function measured in copper mesoscopic wires and offers a simple way to obtain the interbranch carrier mean free path between the well-known ballistic and diffusive regimes. We use this model to study the high-field electro-thermal transport in metallic carbon nanotubes. The approach takes into account the coupled dynamics between charge carrier and phonon populations arising as a consequence of the inelastic scattering processes. From the investigation of the emergence of both charge and optical phonon populations out of equilibrium, our self-consistent approach provides a detailed picture of the heat production/dissipation in carbon nanotubes under high fields. Our work shows remarkable agreement with experiments on metallic carbon nanotubes at room temperature. We specifically demonstrate that while the emergence of transport nonlinearities in the electrical characteristics in these nanostructures is due to the onset of high-energy optical phonon scattering, the shape of those nonlinearities is related to the heat removal mechanisms in the system. We investigate the contribution to transport of subbands when the latter are introduced as a perturbation to the system.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Kuroda, Marcelo

Contributors dc:contributor

• Goldbart, Paul M.

• Physics, Condensed Matter

Language dc:language

eng

Identifier

(MiAaPQ)AAI3392105

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/80614