Investigation of laser modulated thermoelectric power of chiral carbon nanotubes

Abstract

We investigated laser modulated thermopower in chiral carbon nanotubes . This was achieved by solving the Boltzmann transport equation with energy dispersion relation obtained in the tight-binding approximation. Analytical expressions were obtained for the differential thermoelectric power ( α ) along the axial ( α zz ) direction of the nanotubes. We have also noted that laser intensities above a threshold value of 4.6 × 10 7 V/m lower the thermopower, otherwise there is no substantial change. Varying the real overlapping integrals for jumps along the nanotube axis (Δ z ) and base helix (Δ s ) changes the thermopower from a positive to negative type. Our results suggest the possibility of on-demand tuning of the electronic and thermoelectric properties of single wall nanotubes (SWNTs) in the presence of a laser source. • Laser modulated thermopower of chiral carbon nanotubes has been studied using semi-classical Boltzmann's transport equation. • Below threshold laser intensity of 4.6 × 10 7 V/m, thermopower of nanotubes increases with increasing intensity of the applied laser field. • Under some unique conditions, nanotubes behave as either n-type or p-type semiconductors. • Laser induced on-demand tuning of electronic and thermoelectric properties of nanotubes for optoelectronic applications is possible.