Recent advances in designing thermoelectric materials

Abstract

The rising demand for energy has accelerated the search for clean and renewable sources and newer approaches towards efficient energy management. One of the most promising approaches is the conversion of the waste heat into electrical energy by using thermoelectric materials. Such conversion approaches utilize and harvest the waste heat, thereby mitigating the environmental concerns. High-performance thermoelectric materials simultaneously require excellent electronic transport and favorable thermal transport. The performance of any thermoelectric material is determined by the thermoelectric figure of merit (ZT), where the governing parameters such as thermopower and electrical and thermal conductivity are material dependent. Given the interdependence of various transport parameters, designing thermoelectric materials with desirable efficiency is highly challenging. This has fueled the interest in developing new strategies and the search for potential materials, which can unfold broader aspects and provide a larger search space for thermoelectric research. The concept of tuning crystal structures by varying dimensionality, controlling defect chemistry, and modifying atomic order in compounds represents an emerging breakthrough in designing next-generation thermoelectric materials. With the surge in advancements in this emerging field, another step forward is exploring the physical and chemical property-based concepts such as spin driven transport, unusual transport in organic thermoelectric materials, non-trivial bonding and orbital chemistry and many more. This review provides a broad overview of these advanced approaches for improving thermoelectric efficiency with a detailed discussion of the current investigations in this area. Finally, a discussion has been provided highlighting the existing shortcomings and potential prospects.