Influence of Encapsulation of Fullerenes on Optical and Thermoelectric Properties of Carbon Nanotubes
The hybrid systems based on the carbon nanotubes (CNT) and fullerenes (nanopipodes) are promising for applications in nanoelectronics. With insignificant variation of the CNT diameter the change of the fullerenes geometry takes place. The periodically located inside fullerenes represent a set of quantum points in the one-dimensional super-lattice. Using the variation of inside fullerenes it is possible to modulate the zone structure of the CNT - fullerene system and to control the electronic and phonon characteristics of nanopipodes. In the work the optical and thermoelectric properties of CNT with encapsulated molecules of C60 fullerene have been investigated. Using the first-principle methods the coefficients of absorption, optical conductivity, thermal conductivity, thermoelectric figure of merit for CNT with fullerenes, periodically located inside the nanotubes at different distances from each other, have been calculated. It has been shown that with decreasing the distance between fullerenes the optical conductivity of CNT - C60 is suppressed at high frequencies. It has been determined that the conductance of the structures with fullerenes is less than the conductance of a clean tube, and approximately equal for considered distances (12.3 and 19.7 Å) between fullerenes. The CNT thermal conductivity due to the encapsulation of fullerenes considerably (3-4 times) decreases for the considered CNT (8.8) - C60 systems.