Thermoelectric properties of a nanocontact

TL;DR

This paper investigates the thermoelectric properties of a nanocontact between two capped single wall nanotubes, revealing high Seebeck coefficients and figures of merit, and explores how doping and impurities can optimize device performance.

Contribution

It provides a theoretical analysis of thermoelectric behavior in nanotube nanocontacts using tight-binding and Green's function methods, highlighting potential for high-efficiency thermoelectric devices.

Findings

Semiconducting nanotubes exhibit high Seebeck coefficients near Fermi energy.

Figures of merit can exceed one, indicating high thermoelectric efficiency.

Impurities and doping significantly influence thermoelectric properties.

Abstract

Thermoelectric properties of a nanocontact made of two capped single wall nanotubes (SWNT) are calculated within the tight-binding approximation and Green's function method. It is found that semiconducting nanotubes can have high Seebeck coefficient very near the actual Fermi energy. This in turn leads to very high figures of merit easily exceeding one. Modifying the properties by shifting the chemical potential can be achieved by doping or application of a (nano-)gate voltage. The presence of impurities near the contact also strongly modify the properties and this can be taken advantage of, in order to design devices with high thermopower and figures of merit.