空位缺陷对Si薄膜热导率的影响

利用非平衡分子动力学方法研究了空位结构缺陷对Si薄膜热导率的影响。当温度在300K-700K之间变化时，热导率随着空位浓度的增加而降低，并且随着温度的升高空位浓度对热导率的影响以及同一空位浓度下温度对热导率的影响都在逐渐减弱。本文还利用Boltzmann输运理论对MD模拟进行验证，结果基本与其一致。同时理论方法还表明，空位缺陷对薄膜热导率的巨大影响归因于晶格应力的存在使点缺陷也发生散射作用的结果。

Effects of vacancy structural defects on the thermal conductivity of silicon thin films

Vacancy structural defect effects on the lattice thermal conductivity of silicon thin films have been investigated with non-equilibrium molecular dynamics simulation. The lattice thermal conductivities decrease with increasing vacancy concentration at all temperatures from 300 to 700 K. Vacancy defects decrease the sample thermal conductivity, and the temperature dependence of thermal conductivity becomes less significant as the temperature increases. The molecular dynamics result is in good agreement with the theoretical analysis values obtained based on the Boltzmann equation. In addition, theoretical analysis indicates that the reduction in the lattice thermal conductivity with vacancy defects can be explained by the enhanced point-defect scattering due to lattice strain.