Thermal rectification is a behavior that is similar to the electric diode, where heat transport highly relies on the directions. Most of the systems are based on the graded structure or heterostructure. The phenomena usually are contributed to the temperature dependence of the thermal conductivity [1]. Nowadays, the research interests for thermal rectification has been extended from bulk materials to nanosize materials. Phonon behavior is suggested to play more roles in heat transport [2]. As graphene has its unique 2D structure, it is an ideal simplified platform to understand the phonon transport. Recently, both the experimental and theoretical results for thermal rectification based on monolayer graphene have been reported [3-4]. However, the thermal rectification based on the structure-controlled graphene phononic crystal has not been demonstrated yet. In this work, we used the helium ion beam milling technique to build structure-controlled suspended graphene nanomesh devices. By combining with the pristine graphene part, we observed asymmetric thermal transport properties in this kind of homogeneous structure.
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