Evolution of defect structures leading to high ZT in GeTe-based thermoelectric materials.

ABSTRACT: GeTe is a promising mid-temperature thermoelectric compound but inevitably contains excessive Ge vacancies hindering its performance maximization. This work reveals that significant enhancement in the dimensionless figure of merit (ZT) could be realized by defect structure engineering from point defects to line and plane defects of Ge vacancies. The evolved defects including dislocations and nanodomains enhance phonon scattering to reduce lattice thermal conductivity in GeTe. The accumulation of cationic vacancies toward the formation of dislocations and planar defects weakens the scattering against electronic carriers, securing the carrier mobility and power factor. This synergistic effect on electronic and thermal transport properties remarkably increases the quality factor. As a result,

SUBMITTER: Jiang Y 

PROVIDER: S-EPMC9568533 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature