Solidification Engineering for Thermoelectrics: Figure of Merit and Plasticity

Thermoelectric technology facilitates sustainable energy conversion, rendering distinctive advantages for applications, including thermal management and solid-state refrigeration. Solidification technology fundamentally determines the thermoelectric and mechanical properties by shaping the multiscale microstructures of materials, such as grain size, phase distribution, and defect categories. This review systematically elaborates on how solidification-based fabrication strategies uniquely synergize the enhancement of thermoelectric performance and mechanical reliability. Advanced solidification techniques for single crystal and polycrystalline thermoelectric materials enable precise manipulation of multiscale microstructural defects, thereby achieving effective decoupling of electron and phonon transport. This rational design strategy substantially suppresses lattice thermal conductivity while retaining favorable electrical transport properties, ultimately yielding a remarkable improvement in ZT values. Concurrently, the tailored microstructural architectures formed during the solidification process can remarkably improve mechanical ductility and fracture toughness, offering a viable approach to mitigate the intrinsic brittleness commonly associated with conventional thermoelectric materials. Solidification engineering offers a synergistic approach for the development of high-performance thermoelectric devices with robust mechanical properties, laying a solid foundation for the advancement of more reliable and sustainable energy conversion systems.