Recent Advances in Energy Harvesting from Waste Heat Using Emergent Thermoelectric Materials

A powerful economy and a sustainable society are based upon the available energy resources. A nonrenewable energy source is limited in its availability as a result of high consumption rates, output efficiency, and when used at large scale generates a large amount of waste heat and toxic gases. The eco-friendly and long lasting human society has always worked hard to find an alternate source of renewable and clean energy. Material scientists have found possible solutions with the discovery of thermoelectric materials that utilize the waste heat and convert it into useful electricity. This chapter focuses on thermoelectric (TE) materials. The content of this chapter is presented with the assumption that readers have a basic understanding of material’s structural, chemical, and transport properties, as well as the mechanisms responsible for displaying these properties based on computational results. We begin the chapter with an overview of thermoelectric materials and their applications in waste heat energy harvesting. The physical parameters and selection criteria for screening high-performance TE materials are also discussed. To gain a better understanding of TE properties, a brief description of the computational and experimental methods for investigating a material’s crystal structure, electronic and heat transport properties is provided before classifying the category of different materials. With a better understanding of materials properties, a wide range of emergent materials, discovered in recent past years, with high TE performance over a wide temperature range, are covered. We concentrated on the TE properties of chalcogenides, Si–Ge-based alloys, and oxides, in this chapter. For the realization of practical applications, everything from materials to device fabrication and output performance is elaborated. The limitations of conventional approaches and commonly available tools used in TE research, as well as potential solutions, are discussed, paving the way for further investigation of the exceptional properties governed by unusual crystal and electronic structure of materials. Finally, we present a summary of thermoelectric materials as a potential candidate for renewable energy sources in next-generation technological applications.