摘要
We perform non-equilibrium molecular dynamics calculations to study the heat transport in crystalline-core amorphous-shell silicon nanowires(SiNWs).It is found that the thermal conductivity of the core-shell SiNWs is closely related to the cross-sectional area ratio of amorphous shell.Through shell amorphization,an 80%reduction in thermal conductivity compared to crystalline SiNWs with the same size can be achieved,due to the non-propagating heat diffusion in the amorphous region.In contrast to the strong temperature-dependent thermal conductivity of crystalline SiNWs,the core-shell SiNWs only show weak temperature dependence.In addition,an empirical relation is proposed to accurately predict the thermal conductivity of the core-shell SiNWs based on the rule of mixture.The present work demonstrates that SiNWs with an amorphized shell are promising candidates for thermoelectric applications.
基金
the financial support from the Agency for Science,Technology and Research(A*STAR),Singapore
