Designing advanced thermoelectrics

The global pursuit of sustainable energy has accelerated research on thermoelectrics, which convert waste heat into electricity. Nevertheless, progress towards high thermoelectric figure-of-merit (ZT) remains constrained by the trade-off between electrical and thermal transport, requiring rational strategies for their decoupling. Importantly defects, which are thermodynamically unavoidable, perturb both phonons and charge carriers. This Review synthesizes emerging design principles that complement established extrinsic disorder strategies by emphasizing intrinsic control of electronic structure and lattice dynamics. We examine how band engineering and defect design enhance electrical transport without sacrificing carrier mobility, and discuss decoupling mechanisms arising from electronically driven instabilities and crystal symmetry. Moving from materials to devices, we highlight interface design for thermoelectric modules. Ultimately, we outline the potential of physics-informed descriptors derived from these design principles to enable artificial intelligence-assisted discovery and design of advanced thermoelectrics.