High performance p-type organic thermoelectric materials based on metalloporphyrin/single-walled carbon nanotube composite films

Abstract

Single-walled carbon nanotube/organic small molecule based thermoelectric materials have attracted significant scientific attention in recent years. However, up to now, no detailed thermoelectric study reported is focused on the single-walled carbon nanotube/organometallic complex composite films. By considering the excellent properties of tetraphenylporphyrin (such as its π-conjugated system, versatile structure and stability) and the important roles of metal ions in improving thermoelectric properties, metalloporphyrins manifest great potential as composites for single-walled carbon nanotubes. Hence, in this work, we first propose a convenient strategy to obtain high-performance thermoelectric composites containing metalloporphyrin molecules and single-walled carbon nanotubes. It is found that the single-walled carbon nanotube/ZnTPP composite film demonstrates the best thermoelectric performance with a maximum power factor of 247.2 μWm−1K−2 at 340 K, which is perhaps one of the highest thermoelectric power factors reported for single-walled carbon nanotube/organic small molecule-based p-type materials. Three p-type materials exhibit outstanding electric conductivities with a maximum of 1028.7 S cm−1 (single-walled carbon nanotube/CuTPP at 340 K). Furthermore, the produced thermoelectric materials manifest outstanding air stability and thermostability. Therefore, our proposed method can be a promising reference for fabricating novel p-type high-performance thermoelectric materials using metalloporphyrin-based building blocks.