First-principles prediction of phononic thermal conductivity of silicene: A comparison with graphene

By Xiaokun Gu, Ronggui Yang. 2014

235 citations recorded by the source corpus.

There has been great interest in two-dimensional materials, beyond graphene, for both fundamental sciences and technological applications. Silicene, a silicon counterpart of graphene, has been shown to possess some better electronic properties than graphene. However, its thermal transport properties have not been fully studied. In this paper, we apply the first-principles-based phonon Boltzmann transport equation to investigate the thermal conductivity of silicene as well as the phonon scattering mechanisms. Although both graphene and silicene are two-dimensional crystals with similar crystal structure, we find that phonon transport in silicene is quite different from that in graphene. The thermal conductivity of silicene shows a logarithmic increase with respect to the sample size due to the small scattering rates of acoustic in-plane phonon modes, while that of graphene is finite. Detailed analysis of phonon scattering channels shows that the linear dispersion of the acoustic out-of-plane (ZA) phonon modes, which is induced by the buckled structure, makes the long-wavelength longitudinal acoustic phonon modes in silicene not as efficiently scattered as that in graphene. Compared with graphene, where most of the heat is carried by the acoustic out-of-plane (ZA) phonon modes, the ZA phonon modes in silicene only have ∼10% contribution to the total thermal conductivity, which can also be attributed to the buckled structure. This systematic comparison of phonon transport and thermal conductivity of silicene and graphene using the first-principle-based calculations shed some light on other two-dimensional materials, such as two-dimensional transition metal dichalcogenides.

Subfields: Civil and Structural Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/f0ddee7aa2f011200979bab1cba7096639e09e1e

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In Civil and Structural Engineering

1. Baowen Li
2. Xiaokun Gu
3. Xiaobo Yin
4. Ronggui Yang
5. Yujie Wei
6. X. Ruan
7. C. Hua
8. S. Lee

In Materials Chemistry

1. Xiaobo Yin
2. Yujie Wei
3. Baowen Li
4. Xiaokun Gu
5. Ronggui Yang
6. C. Hua
7. S. Lee
8. X. Ruan

Citations in the corpus

• Colloquium: Phononic thermal properties of two-dimensional materials (2017, methodology): “For other 2D crystals, such as buckled honeycomb crystals (Gu and Yang, 2015) and 1T TMDs (Gu and Yang, 2014), there is no symmetry in their crystals which results in stronger phonon scattering compared to planar crystals and 2H TMDs.”
• Neuroevolution machine learning potentials: Combining high accuracy and low cost in atomistic simulations and application to heat transport (2021, result): “5(b). thermal Our lattice conductivity value is also well within the range from previous BTE-DFT calculations [84–87].”
• Survey of ab initio phonon thermal transport (2018, background): “(silicene, germanene, stanene and graphane [15,104,155,163,174]), hexagonal BN [105,163], SnSe [8,54,134], Pd2Se3 [175], InSe [176,177], MXenes [178,179], and borophene and borophane [180e182], to name a few.”