A review from fundamental research to device applications for graphene-based thermal rectifier

Thermal rectification (TR) is a phenomenon akin to electrical rectification. It has a high thermal conductivity (k) in one direction, enabling efficient heat dissipation, as well as a low k in the opposite direction, impeding heat influx. With the rapid development of nanotechnology in recent years, the active control and regulation of heat conduction on the nanoscale has become a critical mission. Graphene, a prominent two-dimensional (2D) material, is highly regarded for its exceptional thermal transport characteristics. There have been studies and achievements both theoretically and experimentally since its discovery. In this review, we establish a bridge between fundamental research and application studies for graphene-based thermal rectifier as follows. Firstly, we summarize the established 2D heat conduction theories and low-dimensional simulation methods. Secondly, we review the progress of experimental techniques and device structures based on 2D theories for graphene-based thermal rectifier. Then, we discuss several applications of thermal rectifier, including thermal logic circuits and thermoelectric power generation system. Finally, we present the potential applications of graphene-based thermal rectifiers previously unexplored, such as microelectronic thermal management and thermal decoupling for flexible equipment. We hope that advancements in morphology and fabrication techniques will lead to widespread use of graphene-based thermal rectifiers in various thermal systems to solve diverse thermal management problems in the near future.