Flexible Thermoelectrics Based on Plastic Inorganic Semiconductors

Flexible thermoelectrics, including flexible thermoelectric materials and devices, can generate electricity by utilizing the small temperature difference between the human body and surrounding environment, exhibiting great potential for the continuous powering of wearable devices. It has long been assumed that inorganic thermoelectric materials are usually brittle at room temperature except for size-induced flexibility. Until recently, this perception has been overturned by the discovery of inorganic semiconductors with intrinsic plastic deformability. Herein, this review provides a comprehensive summary of the recently burgeoning plastic inorganic semiconductors in thermoelectrics. First the requirements to thermoelectric materials are introduced by flexible thermoelectrics. Then, the mechanical properties and potential plastic deformation mechanisms at the atomic level of plastic inorganic semiconductors are systematically summarized. Subsequently, the optimization strategies for the mechanical and thermoelectric properties of plastic inorganic semiconductors, such as doping and alloying, are summarized. Furthermore, the advantages of plastic inorganic semiconductors in flexible thermoelectric devices and their potential applications in wearable electronic devices are also highlighted. Finally, the current challenges are presented and future directions are predicted, including high-throughput screening methods for plastic inorganic semiconductor materials and the development and application of flexible inorganic thermoelectric materials.