Thermal transport across grain boundaries in polycrystalline silicene: A multiscale modeling

Maryam Khalkhali,Ali Rajabpour,Farhad Khoeini

doi:10.1038/s41598-019-42187-w

Maryam Khalkhali, Ali Rajabpour + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-42187-w

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Abstract

During the fabrication process of large scale silicene, through common chemical vapor deposition (CVD) technique, polycrystalline films are quite likely to be produced, and the existence of Kapitza thermal resistance along grain boundaries could result in substantial changes of their thermal properties. In the present study, the thermal transport along polycrystalline silicene was evaluated by performing a multiscale method. Non-equilibrium molecular dynamics simulations (NEMD) was carried out to assess the interfacial thermal resistance of various constructed grain boundaries in silicene. The effects of tensile strain and the mean temperature on the interfacial thermal resistance were also examined. In the following stage, the effective thermal conductivity of polycrystalline silicene was investigated considering the effects of grain size and tensile strain. Our results indicate that the average values of Kapitza conductance at grain boundaries at room temperature were estimated to be nearly 2.56 × 109 W/m2 K and 2.46 × 109 W/m2 K through utilizing Tersoff and Stillinger-Weber interatomic potentials respectively. Also, in spite of the mean temperature, whose increment does not change Kapitza resistance, the interfacial thermal resistance could be controlled by applying strain. Furthermore, it was found that by tuning the grain size of polycrystalline silicene, its thermal conductivity could be modulated up to one order of magnitude.

Highlights

Nowadays, novel two-dimensional materials (2D Materials) have attracted widespread research interest due to their promising application potential in nanotechnology[1,2,3,4]
We used a multiscale method consisting of non-equilibrium molecular dynamics simulations and solving continuum heat conduction equation in order to intensively investigate the effects of grain size and tensile strain on the thermal transport along the polycrystalline silicene
The thermal transport through polycrystalline silicene with performing a multiscale method consisting of classical Non-equilibrium molecular dynamics simulations (NEMD) and solving continuum heat conduction equation were intensively explored

Summary

Introduction

Novel two-dimensional materials (2D Materials) have attracted widespread research interest due to their promising application potential in nanotechnology[1,2,3,4]. The physics in quantum phase transition can be explored with the interaction between the electromagnetic field and spin–orbit coupling in silicene[28,29]. This slightly buckled structure will significantly alter the thermal conductivity of silicene due to breaking the symmetry of the out-of-plane direction. Because the effective procedure to improve the thermoelectric performance is to reduce the thermal conductivity with maintaining the electronic transport features, silicene may show a great advantage as a promising thermoelectric material[30,31]. Among all the developed fabrication methods, the chemical vapor deposition (CVD) is a common approach to synthesize different types of two-dimensional atomic crystals due to its simplicity, the potential large-scale www.nature.com/scientificreports/

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