Thermoelectric properties of a nanocontact made of two-capped single-wall carbon nanotubes calculated within the tight-binding approximation

摘要

Thermoelectric properties of a nanocontact made of two capped single wall carbon nanotubes (SWCNT) are calculated within the tight-binding approximation and by using Green's function method. It is found that doped semiconducting nanotubes can have high Seebeck coefficients. This in turn leads to very high figures of merit (ZT) for p-doped tubes which turn out to have also a large electrical to thermal conductivity ratio. Transport in the nanocontact device is dominated by quantum interference effects, and thus it can be tuned by doping (charge transfer and/or impurity potential) or application of a (nano-)gate voltage, or a magnetic field. Another reason for high ZT in this device is the absence of phonon transport as there is barely a contact.