Silicon-based low-dimensional materials for thermal conductivity suppression: recent advances and new strategies to high thermoelectric efficiency

Thermoelectric (TE) materials can convert any kind of heat into electricity through the Seebeck effect. Harvesting body heat and generating electricity by TE wearable devices can provide a convenient charge service for electrical equipment, even in the case of emergency or disaster. As a high-temperature excellent TE material, silicon also exhibits promising room temperature (RT) potential for wearable TE devices due to its safe and mature production line for the semiconductor industry. Aiming to search for solutions for reducing thermal conductivity (k), this review summarizes the low-dimensional strategies for reducing k based on nanostructural classification, thus enhancing zT at RT, and it also looks into the prospect of wearable application. Following in the footsteps of nanostack (NS), nanowire (NW), nanoporous (NP) and nanocomposite (NC) Sibased TE materials research, we found that the thermal conductivity has been well controlled and that harmonious regulation of the power factor (PF) with k will be the future direction. (c) 2020 The Japan Society of Applied Physics