Abstract
The development of miniaturized, integrated, and flexible thermoelectric devices has intensified the demand for high-performance thermoelectric semiconductors. While significant advances have been made in optimizing their thermoelectric properties, mechanical performance in terms of the strength and ductility has remained a challenge. Consequently, the inherent brittleness and insufficient mechanical robustness of inorganic thermoelectric semiconductors present a major barrier to their commercial applications. Therefore, it is essential to develop thermoelectric materials with enhanced reliability and operational lifespan of flexible thermoelectric devices. This review summarizes recent breakthroughs in low-dimensional thermoelectric materials and emerging defect engineering strategies, which offer promising pathways for simultaneously improving both mechanical and thermoelectrical performance. By precisely regulating the relationship between nanostructural design and performance characteristics, new opportunities are emerging for nanostructured semiconductors in flexible thermoelectric applications across wide temperature ranges, from near-ambient to elevated conditions.