(383c) Interfacial Thermal Conductivity and Its Anisotropy

There is a significant eort in miniaturizing nanodevices, such as semi-conductors,
currently underway. However, a major challenge that is a significant bottleneck is dissipating heat
generated in these energy-intensive nanodevices. In addition to being a serious operational concern
(high temperatures can interfere with their ecient operation), it is a serious safety concern, as has been
documented in recent reports of explosions resulting from many such overheated devices.Asignificant
barrier to heat dissipation is the interfacial films present in these nanodevices. These interfacial films
generally are not an issue in macro-devices. The research presented in this paper was an attempt to
understand these interfacial resistances at the molecular level, and present possibilities for enhancing
the heat dissipation rates in interfaces.We demonstrated that the thermal resistances of these interfaces
were strongly anisotropic; i.e., the resistance parallel to the interface was significantly smaller than the
resistance perpendicular to the interface. While the latter is well-known—usually referred to as Kapitza
resistance—the anisotropy and the parallel component have previously been investigated only for
solid-solid interfaces. We used molecular dynamics simulations to investigate the density profiles at
the interface as a function of temperature and temperature gradient, to reveal the underlying physics
of the anisotropy of thermal conductivity at solid-liquid, liquid-liquid, and solid-solid interfaces.