Revisiting the thermoelectric properties of lead telluride

Considering wastage of two-third of the world's energy consumption in the form of waste heat, the thermoelectric (TE) technology has emerged out as an environmentally friendly and promising energy conversion technology for extracting electrical energy from waste heat. One of the largest obstacles that impede large-scale applications of TE materials is their low conversion efficiencies. Lead telluride stands out as an outstanding thermoelectric material for power generation applications in the mid-temperature range due to its appropriate intrinsic properties. The last decade has witnessed an exceptional development in the TE properties of lead telluride material system, and the maximum figure of merit (zT) has already surpassed a practical criterion of 2 consistently and significantly. This article gives a review of status of current research in the lead telluride alloy material system and the underlying successful strategies to optimize the TE performance. The article outlines diverse strategies like band engineering, nanostructuring, designing all scale hierarchical architectures, synergistic effects, and their outcomes in the form of superior TE performance. Summarizing the review, we emphasize that synergistic effects should be exploited to maximum to boost the TE performance further. In the concluding part, a roadmap for future strategies is proposed, for further enhancement in thermoelectric performance. (C) 2021 Elsevier Ltd. All rights reserved.