Improvement of thermoelectric performance of single-wall carbon nanotubes by heavy doping: Effect of one-dimensional band multiplicity

Abstract

Abstract Doped single-wall carbon nanotube (SWCNT) films were prepared and their Seebeck coefficient ( S ) and electrical resistivity (ρ) were investigated as functions of carrier density. For heavy doping, a second maximum of S ( S = 35 µV/K) was discovered, with its corresponding power factor, P = 85 µW/(m·K 2 ), 6 times that of the first maximum for lightly doped films. Calculations for zigzag SWCNTs suggest that the thermoelectric performance can be effectively improved by controlling the multiplicity of the one-dimensional band and tuning the carrier density. This provides a new strategy for achieving higher performance at a lower cost than using high-purity semiconducting SWCNTs.