High performance of p-type and n-type thermoelectric materials based on liquid crystal mixture and single-walled carbon nanotube composites

Organic small molecule (OSM)/single-walled carbon nanotube (SWCNT) composites are promising thermoelectric (TE) materials, however the low Seebeck coefficient (S) limits their application. Here, a eutectic nematic mixture E7 was chosen to improve the S and power factor (PF) of SWCNTs by energy filtering process. As a result, the introduction of E7 can significantly decrease the carrier concentration of the composite with the mobility greatly enhanced, leading to an improved S (2.23 times of that of pristine SWCNTs). At the mass ratio of 1:0.25, the p-type SWCNT/E7 composites displayed a maximum PF of 428.59 +/- 58.15 mu W m- 1 K-2, which was one of the highest values among OSM-based TE composites reported so far. In addition, after doped with triethylamine, SWCNT/E7 can convert from p-type to n-type. This study demonstrated that SWCNT/E7 composites showed great promise in TE materials and opened up a new avenue for the development of TE materials.

Automated summary

The study demonstrated that the introduction of E7 eutectic nematic mixture can significantly improve the thermoelectric performance of SWCNT composite materials, including increasing the Seebeck coefficient and power factor. Furthermore, after doped with triethylamine, SWCNT/E7 composites can convert from p-type to n-type.