Comparison of thermoelectric properties of sorted and unsorted semiconducting single-walled carbon nanotube free-standing sheets

Abstract

Semiconducting single-walled carbon nanotubes (s-SWCNTs) are promising materials for thermoelectric generation (TEG) because of their large theoretical Seebeck coefficient (S). In this study, to discuss superiority of s-SWCNTs for TEG devices, thermoelectric properties of free-standing s-SWCNT sheets were compared with unsorted SWCNT sheets. To obtain the highest power density, the films were doped with triethyloxonium hexachloroantimonate and 2-(2-methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzo[d]imidazole as the hole and electron dopants, respectively. The doped s-SWCNT sheets exhibited higher S but lower electrical conductivity than those of the unsorted SWCNT sheets. Consequently, the power factor of the s-SWCNT sheets was lower than that of the unsorted SWCNT sheets.