▎ 摘　　要

The Dirac dispersion of graphene limits the phase space available for energy transport between electrons and acoustic phonons at temperatures above the Bloch-Gruneisen temperature. Consequently, energy relaxation can be dominated by supercollision events [Phys. Rev. Lett. 109, 106602 (2012)] also involving other scattering processes. Scattering from out-of-plane (flexural) phonons can compensate for the large momentum transfer involved in scattering from thermal acoustic phonons and enables similar supercollision events, such as disorder. Such multiphonon processes are also allowed by selection rules. I show that for the energy relaxation, the acoustic-flexular process can be of the same order of magnitude as direct flexural and acoustic phonon processes, depending on electronic screening and mechanical strain.