Effectively enhanced thermopower in polyaniline/Bi0.5Sb1.5Te3 nanoplate composites via carrier energy scattering

Abstract

Carrier energy-filtering effect at organic–inorganic interface has been proved to be very effective for improving the performance of polymer-based thermoelectric composites. To introduce a large amount of organic–inorganic interfaces, Bi0.5Sb1.5Te3 nanoplates (BST NP) are fabricated and embedded into camphorsulfonic acid-doped polyaniline (CSA:PANI) through cryogenic grinding followed by hot pressing. It is found that BST NPs are dispersed uniformly in the matrix to form abundant hybrid interfaces in the CSA:PANI/BST NP composites, which shows great enhancement in Seebeck coefficient and power factor. The improvement can be attributed to energy-filtering effect at the CSA:PANI/BST NP interface, which is supported by the distinct transport behavior between CSA:PANI/BST NP and PANI/BST NP composites. Consequently, the maximum ZT values up to 8.637 × 10−4 at 300 K and 1.64 × 10−3 at 400 K are achieved, which is among the best thermoelectric performance of PANI-based bulk composites.