Thermoelectric properties of zigzag single-walled Carbon nanotubes and zigzag single-walled Boron Nitride nanotubes (9, 0)

In this paper, the thermoelectric properties of zigzag singlewalled carbon nanotubes (SWCNT) and zigzag singlewalled boron nitride nanotubes (SWBNNT) are investigated. For this purpose, the chirality is considered as (9, 0). The characteristics are computed at three arbitrary temperatures of 200K, 300K, and 500K. Results show the Seebeck coefficient of zigzag SWCNT increases by increasing the temperature, while decreases for the zigzag SWBNNT. The peak of the Seebeck coefficient of the zigzag SWCNT at the temperatures of 200K, 300K, and 500K are 4.97x10^-5(V/K) ,4.88 ×10^- 5( V/K) , and 5.70 x 10^-5 ( V/K) , respectively. The associated values of SWBNNT are,4.38x10^-3(V/K) ,3.03 ×10^-3( V/K) , and 2.0 x 10^-3( V/K) , and , respectively.Besides, it is observed that at the temperature of 200K, the Seebeck coefficient zigzag SWBNNT is about 88 times the value of zigzag SWCNT. Moreover, due to the Seebeck coefficient sign type in the Fermi energy range, both of the considered nanostructures are semiconductors and ntype. It is depicted that the electrical conductivity and total thermal conductance of SWCNT are larger than SWBNNT. Efficiency is an important parameter to characterize the thermoelectric properties of nanomaterials. Results show the figure-of-merit (ZT) value of SWBNNT is much better than that of SWCNT. Due to the contribution of phonons, the zigzag SWBNNT has larger Seebeck coefficient. The studies show that the maximum value of ZT of the zigzag SWBNNT at the temperatures of 200K, 300K and, 500K are larger than 0.0207, 0.0342 and, 0.0718, respectively. The results of this study can be useful in the design of nanoelectronic, and cooling systems.