Figure 1. Interlayer Coulombic energy transfer between two graphene layers.

(a) Schematic diagram of interlayer Coulombic energy transfer from a hot LD to a cold HD graphene layer. (b) Cooling power of interlayer Coulombic energy transfer as a function of electron temperature for Fermi level E_F,HD=300 meV in the HD graphene layer and various Fermi levels E_F,LD in the LD graphene layer. (c) Ratio of the cooling power of interlayer Coulombic energy transfer to the cooling power of intralayer acoustic phonon cooling as a function of electron temperature for E_F,HD=300 meV, and various values of E_F,LD showing that interlayer Coulombic energy transfer can dominate intralayer acoustic phonon cooling in the LD graphene layer. (d) Ratio of the cooling power of interlayer Coulombic energy transfer to the cooling power of intralayer disorder-assisted electron–phonon (supercollision) cooling as a function of electron temperature for E_F,HD=300 meV, E_F,LD=10 meV (typical for C-face MEG on SiC) and various values of the disorder mean free path in the LD graphene layer showing that interlayer Coulombic energy transfer can dominate intralayer disorder-assisted electron–phonon (supercollision) cooling in the LD graphene layer.