Hexagonal Boron Nitride for Nanoscale Heat Dissipation in Electronic and Photonic Chips

Efficient heat dissipation is critical for chip components, in particular around (sub)microscopic regions with locally elevated power densities, where performance degradation and failure can originate. Here, we experimentally demonstrate enhanced heat dissipation using hexagonal boron nitride (hBN) flakes and heterostructures on gold nanostrips and hexagonal SiGe nanowires. These nanoscale building blocks for electronic and photonic chips simultaneously serve as local temperature sensors. We transferred flakes using dry transfer, ensuring pristine interfaces. Covering gold nanostrips with hBN flakes or hBN/graphene/hBN stacks decreases the temperature ramp rate by up to 40%, and increases the breakdown current density by up to 30%. This occurs through improved in-plane heat dissipation, according to our simulations. Covering hexagonal SiGe nanowires with hBN decreases the operating temperature by up to 500 K under optical excitation, due to improved thermal boundary conductance. These findings pave the way for targeted thermal management in miniaturized electronic and photonic devices.