Layered metal-semiconductor composites for high-performance transverse thermoelectric devices

Devices tailored for efficient thermal energy harvesting may be enabled via the transverse Seebeck effect (TSE) in anisotropic layered metal-semiconductor composites (MSC). As an alternative to single crystal materials, MSCs offer a highly tunable platform to optimize performance characteristics of TSE-based devices and can draw from a broad pool of thermoelectric constituent materials. MSC performance characteristics in applications such as energy harvesting, cooling, and heat flux sensing, were investigated as a function of composite material and geometric parameters (i.e., local layer thickness, global dimensions, and tilt angle). Using a hybrid theoretical and data-driven approach, we propose selection rules that optimize device performance. For highly efficient devices, the two constituent materials must exhibit a large difference in their Seebeck coefficient values (S), in their thermal conductivity values (k), and in the ratio S/k. The relative impact of each selection rule on device performance was investigated using real-world materials parameters.