Thermal conductivity of thin finite-size β-SiC calculated by molecular dynamics combined with quantum correction

Abstract

Silicon carbide (SiC) is a most promising alternative material for the next generation of high-power and high-temperature devices duo to excellent performance, such as larger thermal conductivity compared with Silicon. The thermal conductivity of SiC bulk, as well as temperature dependence of thermal conductivity has been investigated in terms of simulations and experiments. However, when the characteristic size of materials is down to nanoscale, the thermal properties will be significantly different from bulk materials. Thus, it is important to understand the heat transport behavior of SiC thin films for developing nanoscale SiC devices. Nevertheless, thermal properties of SiC thin films have not been investigated systematically. In this paper, a non-equilibrium molecular dynamics model combined with quantum correction is presented for characterizing the thermal conductivity of thin finite-size β-SiC. Adopting the Tersoff empirical potential, temperature effect on thermal conductivity is predicted based on this model. It is found that the uncorrected lattice thermal conductivity diminishes evidently with decrease of temperature. Unlike the uncorrected results, the corrected results display a slight increase with temperature to a maximum value at ∼760 K This work provides a possible theoretical and computational basis for heat transfer and dissipation applications of nanoscale β-SiC thin film, and would also help the design of thermal barriers or new thermoelectric materials.