Enhancement of thermal rectification by asymmetry engineering of thermal conductivity and geometric structure for multi-segment thermal rectifier

Thermal rectification is an exotic thermal transport phenomenon, an analog to electrical rectification, in which heat flux along one direction is larger than that in the other direction and is of significant interest in electronic device applications. However, achieving high thermal rectification efficiency or rectification ratio is still a scientific challenge. In this work, we performed a systematic simulation of thermal rectification by considering both efforts of thermal conductivity asymmetry and geometrical asymmetry in a multi-segment thermal rectifier. It is found that the high asymmetry of thermal conductivity and the asymmetry of the geometric structure of multi-segment thermal rectifiers can significantly enhance the thermal rectification, and the combination of both thermal conductivity asymmetry and geometrical asymmetry can further improve thermal rectification efficiency. This work suggests a possible way for improving thermal rectification devices by asymmetry engineering.