Thermal conduction across a boron nitride and SiO₂ interface

The need for efficient heat removal and superior thermal conduction in nano/micro devices has triggered tremendous studies in low-dimensional materials with high thermal conductivity. Hexagonal boron nitride ( h -BN) is believed to be one of the candidates for thermal management and heat dissipation due to its novel physical properties, i.e. as a thermal conductor and electrical insulator. Here we report the interfacial thermal resistance between few-layer h -BN and its SiO₂ substrate using the differential 3 ω method. The measured interfacial thermal resistance is around ∼1.6  ×  10⁻⁸ m²K W⁻¹ for monolayer h -BN and ∼3.4  ×  10⁻⁸ m²K W⁻¹ for 12.8 nm-thick h -BN in metal/ h -BN/SiO₂ interfaces. Our results suggest that the voids and gaps between the substrate and thick h -BN flakes limit the interfacial thermal conduction. This work provides a deeper understanding of utilizing h -BN flakes as a lateral heat spreader in electronic and optoelectronic nano/micro devices with further miniaturization and integration. (paper)