Molecular dynamic simulation thermal conductivity of single/crystal carbon and germanium thin films

NEMD calculations are employed for the thermal conductivity of single crystal carbon and germanium films in normal direction. The results of calculations demonstrate that, at the temperature ranging from 300 to 500 K, the thermal conductivity in normal direction of the crystal carbon films with the thickness of about 2-5 nm is remarkably lower than the corresponding experimental data of the bulk, and rises with the increase of the film thickness in a approximate linear trend; as for the germanium film with the thickness of about 2.8175-11.27 nm, in the temperature range of 300-500 K, the size effect on the thermal conductivity remains notable and the thermal conductivity also rises with the increase of the film thickness in a approximate linear trend; the thermal conductivity of the crystal carbon and germanium films decreases with the increase of the temperature.