Ultrahigh thermal conductivity in hexagonal BC6N- An efficient material for nanoscale thermal management- A first principles study

TL;DR

This study uses first principles calculations to reveal that hexagonal BC6N exhibits extremely high thermal conductivity, making it a promising material for nanoscale heat dissipation in electronic devices.

Contribution

The paper reports the first theoretical prediction of ultra-high thermal conductivity in hexagonal BC6N, comparable to diamond, and analyzes size-dependent effects in nanostructures.

Findings

Thermal conductivity of 2090 W/m·K in bulk BC6N

High thermal conductivity in nanostructures at 175 W/m·K for 100 nm length

Attribution of high thermal conductivity to strong bonds and light atoms

Abstract

Engineering materials with high thermal conductivity are of fundamental interest for efficiently dissipating heat in micro/nanoelectronics. Using first principles computations we report an ultra-high thermal conductivity of 2090 Wm-1K-1 (1395 Wm-1K-1) for hexagonal pure (natural) BC6N(h-BC6N). This value is among the highest thermal conductivities known after diamond and cubic boron arsenide. This ultra-high lattice thermal conductivity (k) is mainly attributed with high phonon group velocities of both acoustic and optical phonons arising from strong C-C and B-N bonds as well as the light atomic mass of the constituent elements such as boron (B), carbon (C) and nitrogen (N). We also report size dependent thermal conductivity of h-BC6N nanostructures by including boundary scattering. At room temperature (300 K) and at nanoscale length (L) of 100 nm, a high k value of 175 Wm-1K-1 is observed (higher than the bulk k value of silicon). Optical phonons with large group velocities are mainly responsible for this high thermal conductivity in h-BC6N nanostructures. High thermal conductivity of h-BC6N makes it a candidate material for heat dissipation in micro/nano thermal management applications.