Quantifying the limits of through-plane thermal dissipation in 2D-material-based systems

Through-plane thermal transport accounts for a major fraction of heat dissipation from hot-spots in many existing devices made of two-dimensional (2D) materials. In this report, we performed a set of electrical thermometry measurements and 3D finite element analyses to quantify the limits of power dissipation in monolayer graphene, a representative of 2D materials, fabricated on various technologically viable substrates such as chemical vapor deposited (CVD) diamond, tape-casted (sintered) aluminum nitride (AlN), and single crystalline c-plane sapphire as well as silicon with different oxide layers. We demonstrate that the heat dissipation through graphene on AlN substrate near room temperature outperforms those of CVD diamond and other studied substrates, owing to its superior thermal boundary conductance (TBC). At room temperature, our measurements reveal a TBC of 33.5 MW . m(-2) . K-1 for graphene on AlN compared to 6.2 MW . m(-2) . K-1 on diamond. This study highlights the importance of simultaneous optimization of the interfaces and the substrate and provides a route to maximize the heat removal capability of 2D-material-based devices.