▎ 摘　　要

A model is suggested for the intermediate interaction of Dirac fermions with coupled plasmon-phonon modes in monolayer graphene on a polar substrate. We introduce a diagonalization procedure based on Lee-Low-Pines transformations to study the properties of both hole and electron polarons. Exact expressions are obtained for the energies of Dirac fermions taking into account their scattering by collective excitations. It is analytically shown that the Fermi velocity renormalizations for electrons and holes have the same values and depend only on the strength of the coupling between Dirac fermions and elementary excitations in the heterostructure under consideration. The obtained results can be used in order to control the electronic properties, which can provide interesting characteristics of optoelectronic devices.