Decorated Dislocations Against Phonon Propagation for Thermal Management

Τhe impact of decorated dislocations on the effective thermal conductivity of GaN is investigated by means of equilibrium molecular dynamics simulations via the Green-Kubo approach. The formation of In embedded nanowires in the core of dislocations in wurtzite GaN is found to affect the thermal properties of the material, as it leads to a significant decrease of the thermal conductivity, along with an enhancement of its anisotropic character. The thermal conductivity of In-decorated dislocations is compared to the ones of pristine GaN, InN, random and ordered InxGa(1-x)N alloys, to examine the impact of doping. The temperature dependence of the thermal conductivity is also examined. Results are explained by the stress maps, the bonding properties, the phonon density of states and the wavepacket propagation analysis of the aforementioned systems. The decorated dislocations engineering is proposed as a way to tune, among other transport properties, the effective thermal conductivity of materials at the nano...