Theory of interfacial plasmon-phonon scattering in supported graphene

Abstract

One of the factors limiting electron mobility in supported graphene is remote phonon scattering. We formulate the theory of the coupling between graphene plasmon and substrate surface polar phonon (SPP) modes and find that it leads to the formation of interfacial plasmon-phonon (IPP) modes, from which the phenomena of dynamic antiscreening and screening of remote phonons emerge. The remote phonon-limited mobilities for SiO${}_{2}$, HfO${}_{2}$, h-BN, and Al${}_{2}$O${}_{3}$ substrates are computed using our theory. We find that hexagonal boron nitride (h-BN) yields the highest peak mobility, but in the practically useful high-density range, the mobility in HfO${}_{2}$-supported graphene is high, despite the fact that HfO${}_{2}$ is a high-$\ensuremath{\kappa}$ dielectric with low-frequency modes. Our theory predicts that the strong temperature dependence of the total mobility effectively vanishes at very high carrier concentrations. The effects of polycrystallinity on IPP scattering are also discussed.