Enhanced thermoelectric performance in spark plasma textured bulk n-type BiTe2.7Se0.3 and p-type Bi0.5Sb1.5Te3

TL;DR

This study demonstrates that spark plasma texturization significantly enhances the thermoelectric performance of bulk n-type BiTe2.7Se0.3 and p-type Bi0.5Sb1.5Te3 by reducing thermal conductivity and increasing figure of merit.

Contribution

The paper introduces a spark plasma texturization technique that improves thermoelectric properties of bismuth telluride materials beyond conventional methods.

Findings

42% increase in figure of merit for n-type BiTe2.7Se0.3

33% increase in figure of merit for p-type Bi0.5Sb1.5Te3

Reduced thermal conductivity in textured samples

Abstract

Bulk p and n-type bismuth telluride were prepared using spark plasma texturization method. The texture development along the uniaxial load in the 001 direction is confirmed from both x-ray diffraction analysis and Electron Backscattering Diffraction measurements. Interestingly, those textured samples outperform the samples prepared by conventional spark plasma sintering (SPS) leading to a reduced thermal conductivity in the ab-plane. The textured samples of n- type BiTe2.7Se0.3 and p-type Bi0.5Sb1.5Te3 showed a 42% and 33% enhancement in figure of merit at room temperature respectively, as compared to their SPS counterparts, opening the route for applications.