Geometric design of Cu₂Se-based thermoelectric materials for enhancing power generation

Waste heat, an abundant energy source generated by both industries and nature, has the potential to be harnessed into electricity via thermoelectric power generation. The performance of thermoelectric modules, typically composed of cuboid-shaped materials, depends on both the materials’ intrinsic properties and the temperature difference created. Despite significant advancements in the development of efficient materials, macroscopic thermal designs capable of accommodating larger temperature differences have been largely underexplored because of the challenges associated with processing bulk thermoelectric materials. Here we present the design strategy for Cu₂Se thermoelectric materials for high-temperature power generation using a combination of finite element modelling and 3D printing. The macroscopic geometries and microscopic defects in Cu₂Se materials are precisely engineered by optimizing the 3D printing and post-treatment processes, leading to notable enhancements in the material efficiency and temperature difference across legs, where the hourglass geometry exhibits maximized output powers and efficiencies. The proposed approach paves the way for designing efficient thermoelectric power generators.