High-entropy-stabilized chalcogenides with high thermoelectric performance

TLDR

Thermoelectric technology generates electricity from waste heat, but one bottleneck for wider use is the performance of thermoelectric materials. By introducing multiple atomic species to manipulate configurational entropy, the authors stabilized a high‑entropy PbSe-based material whose distorted lattices generate shear strains that strongly scatter phonons and reduce lattice thermal conductivity. The high‑entropy PbSe material achieved a figure of merit of 1.8 at 900 K and a segmented module efficiency of 12.3 % for ΔT = 507 K, demonstrating that entropy engineering can substantially improve thermoelectric performance.

Abstract

Thermoelectric technology generates electricity from waste heat, but one bottleneck for wider use is the performance of thermoelectric materials. Manipulating the configurational entropy of a material by introducing different atomic species can tune phase composition and extend the performance optimization space. We enhanced the figure of merit (zT) value to 1.8 at 900 kelvin in an n-type PbSe-based high-entropy material formed by entropy-driven structural stabilization. The largely distorted lattices in this high-entropy system caused unusual shear strains, which provided strong phonon scattering to largely lower lattice thermal conductivity. The thermoelectric conversion efficiency was 12.3% at temperature difference ΔT = 507 kelvin, for the fabricated segmented module based on this n-type high-entropy material. Our demonstration provides a paradigm to improve thermoelectric performance for high-entropy thermoelectric materials through entropy engineering.