Nanotwinned thermoelectric materials

Thermoelectric materials is the key energy conversion unit of thermoelectic module, whose figure of merit ZT determines largely the energy conversion efficiency of thermoelectric modules. Therefore, how to improve the ZT values of thermoelectric materials has become a research focus in thermoelectric community. Recently, nanotwins have attracted great attention in thermoelectric community because of its merits of low carrier scattering, strong phonon scattering, and effective hindering effect on dislocation motion. Theoretical and experimental studies have shown that nanotwins have great potential in improving the thermoelectric properties (i.e., figure of merit ZT ) and mechanical properties (e.g., plastic deformation strength, fracture toughness) of thermoeletric materials. Herein, we summary the progress of theoretical and experimental reseach on nanotwinned thermoelectric materials, including bismuth telluride alloys, Cu-Sn-S based semiconductors, InSb semiconductor, constantan based alloys, and high entropy semiconductor, providing feasible reference for nanotwins design of other thermoelectric materials. Twins, especially nanotwins have been regarded as an important way to synergistically regulate the thermoelectric and mechanical performance of thermoelectric materials in recently years. Nanotwinned thermoelectric materials have become one of the popular topics in thermoelectric community. This work summaries the theoretical and experimental study on typical nanotwinned thermoelectric materials, thus to provide feasible references for further research.