Thermal conductivity of θ-TaN polycrystal from first principles

Thermal management is an increasingly important issue in the design of new generations of electronic and optoelectronic devices. In this context, new high thermal conductivity materials are highly desirable to reduce the power density of hot spots in ultra-scaled transistors. Recently, a first principle study has found [1] that the lattice thermal conductivity of semimetallic the θ-TaN can be as high as 1000W/mK. In this work, we perform a detailed computational study of the thermal conductivity of this compound, and we analyze and quantify the key phonon scattering mechanisms. We compare our calculations to experimental data on recently-synthesized samples of θ-TaN, and we find that the thermal conductivity of the experimental samples is primarily limited by grain boundary scattering. We discuss possible avenues to increase the thermal conductivity toward the ideal theoretical limit.