Efficient heat dissipation in devices by graphene/hexagonal boron nitride in-plane heterostructure

Atomically thin two-dimensional materials, such as graphene and transition metal dichalcogenides, have demonstrated immense potential to outperform silicon as channel materials for field-effect transistors. However, the continuous shrinking of the device size escalates the power density and imposes a significant challenge in thermal management. Here, we employ graphene/hexagonal boron nitride in-plane heterostructures to regulate the temperature of graphene-based devices and mitigate electrical constraints. At the microscale, the heterostructure introduces additional hexagonal boron nitride heat sinks on both sides of the graphene channel, dispersing the hotspot and notably reducing channel temperature. At the nanoscale, the heterostructure extends the phonon mean free path of the graphene nanoribbon, enhancing the in-plane thermal conductivity of the graphene channel. This improvement facilitates increased heat transfer to the electrodes, amplifying the current-carrying capacity of the graphene nanodevices and achieving an unprecedented power density. These findings provide valuable insights into the effective thermal management of devices.