Direct Joule-Heated Non-Equilibrium Synthesis Enables High Performing Thermoelectrics

TL;DR

The paper introduces Direct Joule-Heated Synthesis (DJS), a rapid, energy-efficient method for producing high-performance thermoelectric materials with microstructural features that enhance phonon scattering, significantly accelerating material discovery.

Contribution

DJS is a novel, scalable synthesis technique that drastically reduces time and energy consumption while enabling the creation of advanced thermoelectric materials with superior properties.

Findings

DJS achieves a 10^5-fold speedup and 20,000x energy efficiency improvement.

Synthesized materials exhibit a high zT of 2.3 at 573 K.

Microstructural features like nanodomains enhance phonon scattering.

Abstract

High-throughput synthesis of bulk inorganic materials is crucial for accelerating functional materials discovery but is hindered by slow, energy-intensive solid-state methods. We introduce Direct Joule-Heated Synthesis (DJS), a rapid, single-step and scalable solid-state synthesis technique achieving a $10^5$-fold speedup and 20,000x energy efficiency improvement over conventional synthesis. DJS enables the synthesis of dense, bulk chalcogenides ($\mathrm{Bi_{0.5}Sb_{1.5}Te_3}$, $\mathrm{AgSbTe_2}$), achieving a zT of 2.3 at 573 K in optimally Cd/Se co-doped $\mathrm{AgSbTe_2}$, one of the highest for polycrystalline materials at this temperature. DJS enables optimal co-doping and rapid, non-equilibrium solidification, producing lamellar microstructures, interfacial regions, and cation-ordered nanodomains that scatter all-scale phonons, achieving ultralow lattice thermal conductivity (~0.2 $W m^{-1} K^{-1}$ at 573 K). DJS establishes a new benchmark for scalable and fast synthesis, accelerating functional material discovery.