Thermal transport in two-dimensional C3N/C2N superlattices: A molecular dynamics approach

Nanostructured superlattices have been the focus of many researchers due to their physical and manipulatable properties. They aim to find promising materials for new electronic and thermoelectric devices. In the present study, we investigate the thermal conductivity of two-dimensional (2D) C3N/C2N super lattices using non-equilibrium molecular dynamics. We analyze the dependence of thermal conductivity on the total length, temperature, and the temperature difference between thermal baths for the super lattices. The minimum thermal conductivity and the phonon mean free path at a superlattice period of 5.2 nm are 23.2 W/m.K and 24.7 nm, respectively. Our results show that at a specific total length, as the period increases, the number of interfaces decreases, thus the total thermal resistance decreases, and the effective thermal conductivity of the system increases. We found that at long lengths (L-x > 80 nm), the high-frequency and low-wavelength phonons are scattered throughout the interfaces, while at short lengths, there is a wave interference that reduces the thermal conductivity. The combination of these two effects, i.e., the wave interference and the interface scattering, is the reason for the existence of a minimum thermal conductivity in superlattices. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, the thermal conductivity of two-dimensional C3N/C2N superlattices was investigated using non-equilibrium molecular dynamics. It was found that with an increase in period, the number of interfaces decreases, leading to a decrease in total thermal resistance and an increase in effective thermal conductivity at a specific total length. At long lengths, high-frequency and low-wavelength phonons are scattered throughout the interfaces, while at short lengths, wave interference reduces thermal conductivity. The combination of wave interference and interface scattering is the reason for the existence of a minimum thermal conductivity in superlattices.