Fig. 1.

Overview of the cavity-graphene thermal emitter. a Schematic of a cavity-integrated hBN/graphene/hBN light emitter with edge contacts. b Optical image of the fabricated device. Scale bar: 5 μm. c Schematic of energy relaxation of graphene hot electrons. The red block corresponds to quasi-equilibrium of hot graphene electrons and optical phonons of graphene and hBN. Subsequently, the heat flows to the acoustic phonons and the substrate. d FDTD simulation of the electric field profile |E|² of the silicon PPC air-slot cavity indicates strongly confined resonant modes. Scale bar: 1 μm. e Reflection spectra of the PPC cavity before (blue) and after (red) deposition of graphene on the PPC surface