Thermal transport characterization of carbon and silicon doped stanene nanoribbon: an equilibrium molecular dynamics study

Abstract

Equilibrium molecular dynamics simulation has been carried out for the thermal transport characterization of nanometer sized carbon and silicon doped stanene nanoribbon (STNR). The thermal conduction properties of doped stanene nanostructures are yet to be explored and hence in this study, we have investigated the impact of carbon and silicon doping concentrations as well as doping patterns namely single doping, double doping and edge doping on the thermal conductivity of nanometer sized zigzag STNR. The room temperature thermal conductivities of 15 nm × 4 nm doped zigzag STNR at 2% carbon and silicon doping concentration are computed to be 9.31 ± 0.33 W m^-1 K^-1 and 7.57 ± 0.48 W m^-1 K^-1, respectively whereas the thermal conductivity for the pristine STNR of the same dimension is calculated as 1.204 ± 0.21 W m^-1 K^-1. We find that the thermal conductivity of both carbon and silicon doped STNR increases with the increasing doping concentration for both carbon and silicon doping. The magnitude of increase in STNR thermal conductivity due to carbon doping has been found to be greater than that of silicon doping. Different doping patterns manifest different degrees of change in doped STNR thermal conductivity. Double doping pattern for both carbon and silicon doping induces the largest extent of enhancement in doped STNR thermal conductivity followed by single doping pattern and edge doping pattern respectively. The temperature and width dependence of doped STNR thermal conductivity has also been studied. For a particular doping concentration, the thermal conductivity of both carbon and silicon doped STNR shows a monotonic decaying trend at elevated temperatures while an opposite pattern is observed for width variation i.e. thermal conductivity increases with the increase in ribbon width. Such comprehensive study on doped stanene would encourage further investigation on the proper optimization of thermal transport characteristics of stanene nanostructures and provide deep insight in realizing the potential application of doped STNR in thermoelectric as well as thermal management of stanene based nanoelectronic devices.

Fig. 1. (a) Top view and (b) front view for the atomistic representation of a pristine zigzag STNR. The buckling height is shown in (b). Schematic representation of doped STNR with (c) single doping (d) double doping and (e) edge doping patterns. The tin and doped atoms are depicted by dark blue and red colored balls, respectively. Modeled structure is doped with either carbon or silicon atoms.

Fig. 2. Thermal conductivity of 15 nm × 4 nm doped STNR (single doped) as a function of (a) carbon and (b) silicon doping concentration. The solid lines depict the numerically fitted curves through the data. The corresponding envelopes of normalized HCACF profiles for different doping concentrations are shown in the insets.

Fig. 3. Phonon density of states for representative pristine stanene, silicene and graphene nanoribbons.

Fig. 4. Ratio of thermal conductivity for carbon doped STNR (K_{C doped}) and that of silicon doped STNR (K_{Si doped}) as a function of doping concentration.

Fig. 5. Thermal conductivity of 15 nm × 4 nm doped STNR as a function of (a) carbon and (b) silicon doping concentration for single, double and edge patterned doping. The solid lines represent the numerically fitted curves through the data. Normalized HCACF curves as well as their envelopes versus correlation time with 0.3% (c) carbon and (d) silicon doping for single, double and edge patterned doping at room temperature.

Fig. 6. Total energy of different types of doped STNRs as a function of simulation time at room temperature for (a) carbon doping (b) silicon doping.

Fig. 7. Thermal conductivity of 15 nm × 4 nm doped STNR as a function of temperature with various doping concentrations for (a) carbon and (b) silicon doping. The solid lines represent the numerically fitted curves through the data.

Fig. 8. Room temperature thermal conductivity of doped STNR as a function of the nanoribbon width with varying doping concentrations for (a) carbon and (b) silicon doping. The nanoribbon length is fixed at 15 nm. The solid lines represent the numerically fitted curves through the data.