Microstructural Design of Bi2Te3- In2Te3 Thermoelectric Composites

Abstract

Abstract Internal interfaces are known to play a key role for the performance of thermoelectric materials. In the present work, structures with high interface densities consisting of alternating Bi2Te3 and In2Te3 layers with varying thickness and distance have been generated by two processes. First In2Te3 was precipitated from a supersaturated Bi2Te3 matrix. Second, layered structures were generated by directional solidification of hypoeutectic and eutectic alloys, demonstrating the variability of structures with high interface densities and anisotropy that can be generated by up-to-date solidification and phase transformation techniques. The resulting microstructures have a high potential to reduce the thermal conductivity while retaining a high electric conductivity.