Phonon transport in amorphous carbon using Green–Kubo modal analysis

Amorphous carbon (a-C) is an important material often used in microelectronics. Using a recently developed approach, termed Green–Kubo modal analysis, we were able to calculate the thermal conductivity of a-C, which yielded excellent agreement with experiments, by employing a simple correction to the specific heat. The results show that the heat capacity substantially limits the thermal conductivity of a-C at room temperature and it is dominated by contributions from diffusons between 10 and 40 THz. Furthermore, the phonon relaxation times in a-C do not vary significantly with increasing temperature, which is quite unusual by comparison with the behavior observed for other materials.