Diffusive nature of thermal transport in stanene

Abstract

Using the phonon Boltzmann transport formalism and density functional theory based calculations, we show that stanene has a low thermal conductivity. For a sample size of 1×1 µm 2 (L × W ), the lattice thermal conductivities along the zigzag and armchair directions are 10.83 W/m-K and 9.2 W/m-K respectively, at room temperature, indicating anisotropy in the thermal transport. The low values of thermal conductivity are due to large anharmonicity in the crystal resulting in high Grüneisen parameters, and low group velocities. The room temperature effective phonon mean free path is found to be around 17 nm indicating that the thermal transport in stanene is completely diffusive in nature. Furthermore, our study brings out the relative importance of the contributing phonon branches and reveals that, at very low temperatures, the contribution to lattice thermal conductivity comes from the flexural acoustic (ZA) branch and at higher temperatures it is dominated by the longitudinal acoustic (LA) branch. We also show that lattice thermal conductivity of stanene can further be reduced by tuning the sample size and creating rough surfaces at the edges. Such tunability in the lattice thermal conductivity in stanene suggests its applications in thermoelectric devices.

Thermal transport in graphene/stanene hetero-bilayer nanostructures with vacancies: an equilibrium molecular dynamics study

“…With the increase in temperature, the number of phonons increases. Consequently phononphonon scattering, specically Umklapp scattering 28,36,37 increases. Hence with the increase in temperature, HCACF prole decays to zero in a shorter time 38 resulting in the computation of decreasing thermal conductivity.…”

“…long wavelength phonons are the majority heat carriers in graphene 35 and stanene. 37 The localization of these heat carriers in the presence of vacancies reduces the thermal transport capability of the graphene/stanene heterobilayer structure. Moreover, strong inelastic scattering at around the vacancy centers as well as at a distance from the vacancy centers 38 causes an overall reduction in the thermal conductivity of the heterobilayer structure with vacancies.…”

Characterization of thermal and mechanical properties of stanene nanoribbons: a molecular dynamics study

“…The results of Peng et al 34 predict that stanene is a suitable candidate for next-generation thermoelectric devices with its high thermoelectric efficiency. Nissimagoudar et al 35 studied the diffusive nature of the thermal conductivity of a stanene sheet using a phonon Boltzmann transport formalism and density functional theory calculations. For a stanene sheet with a sample size of 1 mm  1 mm, the calculated lattice thermal conductivities along the zigzag and armchair directions are 10.83 W m À1 K À1 and 9.2 W m À1 K À1 respectively, at room temperature.…”

Phonon transport properties of two-dimensional group-IV materials from ab initio calculations

“…Thus, systematic investigation of phonon transport properties for 2D group-IV materials is needed.Detailed theoretical investigations have predicted that the thermal conductivity κ of graphene and silicene are in the range of 2000-5000 W/mK and 20-30 W/mK, respectively 6,21-30 . Moreover, strain effects on lattice thermal conductivity of 2D group-IV crystals have been investigated 25,30,31 .However, due to the violation of crystal symmetry, translational invariance and rotational invariance in 2D materials in the computational algorithms 32 , in silicene, germanene and stanene, the flexural acoustic branch usually has a linear component 31,33 , which significantly influence the phonon transport. To get a more precise estimation, in our calculations, all the invariance con-…”

“…However, due to the violation of crystal symmetry, translational invariance and rotational invariance in 2D materials in the computational algorithms 32 , in silicene, germanene and stanene, the flexural acoustic branch usually has a linear component 31,33 , which significantly influence the phonon transport. To get a more precise estimation, in our calculations, all the invariance con-…”