10:30 AM - 10:45 AM
▼ [13a-N106-1] Molecular dynamics study on Asymmetric graphene nanomesh thermal rectifier
Keywords:graphene nanomesh, thermal rectification, Molecular dynamics simulation
With the high-speed development of VLSI technology, thermal management becomes more and more challenging for the “More-than-Moore” era. The thermal rectifier or thermal diode is one of the important keys to lead people to open a new world in which thermal current can be well-controlled as electrical current for energy harvest and recycle. Some great efforts have been made to show that the thermal rectifier can be achieved by hetero-junctions, asymmetric nanostructures, and inhomogeneously mass loading. However, most of the previous reports show a limited thermal rectification ratio which is just around 10-20%. Both the high-efficiency working device and related mechanism are highly demanded. In this project, we introduce the graphene nanomesh (GNM) structure to the suspended graphene devices for developing a high-performance thermal rectifier. The GNM is formed by patterning periodic nanopores on the half area of the suspended graphene with the helium ion beam milling technology. Our previous experimental results showed that up to 60% thermal rectification ratio was observed at 150 K. And it also showed that the conventional κ-T dependence method lost efficacy to explain the nanopore pitch dependence of the asymmetric GNM device. In this paper, we use the molecular dynamics simulation to investigate the mechanism of the thermal rectification phenomenon on our asymmetric graphene devices. With the growth of the capacity of computers, realistic finite-size structures with non-periodic domains can be simulated. And the heat flux can be directly calculated based on Fourier’s law in molecular dynamics simulation. These advantages enable to provide practical guiding principles for future experiment by manipulating some key factors like nanopore pitch and diameter.