Enhancement of the thermoelectric performance of a single-walled carbon nanotube via Al, Si, P, and S impurities

Abstract

Using the tight-binding approach based on density functional theory (DFT) and nonequilibrium Green's function (NEGF) computations, the potential use of single-walled carbon nanotubes (SWCNTs) as high-performance thermoelectric materials is studied. Consequently, the structural, electrical, and thermoelectric characteristics of pristine and X (Al, Si, P, and S) -doped SWCNTs are studied. It has been observed that Al, Si, P, and S impurities open the band structure of SWCNTs. In Boltzman theory, transport factors including the Seebeck coefficient (S), thermal conductivity (k), and figure of merit (ZT) are dependent on the band structure. Therefore, band structure has a significant impact on thermoelectric properties. The findings reveal that the thermoelectric performance of doped SWCNTs surpasses that of their pristine SWCNTs counterparts, and the figure of merit value of doped CNTs is increased to high as ∼2, which implies their very attractive thermoelectric applications.