(590d) Prediction of Thermal Conductivity of Silicon Nanowires on Basis of High Performance Computing

Silicon nanowires are widely applied in field-effect transistors, thermoelectric devices, biological and chemical sensors etc. However, its thermophysical properties and heat transport play an important role in the function and performance of these above-mentioned devices, which has not been investigated completely and comprehensively in physical experiments.

By developing a scalable and highly efficient nonequilibrium molecular dynamics (NEMD) simulation method based on bond-order potentials, we are now able to overcome the long-lasting finite size effects in the computation of the thermal conductivity of silicon nanowires and obtain a thorough knowledge of its mechanical and thermal properties using the contemporary excellent supercomputers, such as Tianhe-1A, Sunway TaihuLight et al [1, 2]. The longitudinal sizes of the simulated systems are much longer than micrometer, which can help to shed light on the complete scale-dependence of thermal conductivities and heat transport mechanism especially at the elusive mesoscopic scale. Furthermore, the transverse feature sizes are far beyond ten nanometers, which can be directly compared to the silicon nanowires fabricated and measured experimentally [3]. Generally, the traditional transverse simulation size is in the range of less than ten nanometers. This powerful virtual computation implemented on the supercomputers can reach the direct prediction of thermal conductivity of silicon nanowires, and can be extended to detailedly depict the thermophysical properties of other low-dimensional structures of covalent solids, such as carbon nanotubes, graphene and so forth.

References

[1] C. Hou, J. Xu, P. Wang, et al, Petascale molecular dynamics simulation of crystalline silicon on Tianhe-1A. International Journal of High Performance Computing Applications, 27, 307-317, 2013.

[2] H. Fu, J. Liao, J. Yang, et al, The Sunway TaihuLight supercomputer: system and applications. Science China: Information Sciences, 59, 072001, 2016.

[3] C. Hou, J. Xu, W. Ge, J. Li, Molecular dynamics simulation overcoming the finite size effects of thermal conductivity of bulk silicon and silicon nanowires. Modelling and Simulation in Materials Science and Engineering, 24, 045005, 2016.