First principles investigation of ultrahigh thermal conductivity materials

Materials with high thermal conductivity(k) are critical for efficient heat dissipation in power electronics, electronics cooling, data center, energy storage and energy conversion technologies in order to improve the system reliability. Especially, k at nanoscale is crucial for increasing the number of transistors embedded in a given chip to meet the ever-increasing demand of computational power without sacrificing its durability. In this work, we are reporting some advanced high thermal conductivity materials such as h-BC6N, h-GeC, h-BC2P and BC5. Interestingly, these materials also have a good thermal conductivity in nanostructured systems (L=50 -100 nm) due to its contributions from optical phonons with phonon meanfreepaths lower than its system size. We also report thermal conductivity enhancement through biaxial strain. We report 710% and 35% enhancement in k for 2D-GeC (6% biaxial tensile strain) and zinc-blende boron phosphide(4% biaxial compressive strain) respectively through biaxial strain. This work provides an avenue to explore and tune k of high thermal conductivity materials in both bulk and nanoscale.

Keywords: Thermal management systems, Phonons, Semiconductors, First principles calculations, Nanostructures