High-Mobility Few-Layer Graphene Field Effect Transistors Fabricated on Epitaxial Ferroelectric Gate Oxides

The carrier mobility μ of few-layer graphene (FLG) field-effect transistors increases tenfold when the SiO₂ substrate is replaced by single-crystal epitaxial Pb(Zr0.2Ti0.8)O₃ (PZT). In the electron-only regime of the FLG, μ reaches 7×10⁴ cm²/V s at 300 K for n=2.4×10¹²/cm², 70% of the intrinsic limit set by longitudinal acoustic (LA) phonons; it increases to 1.4×10⁵ cm²/V s at low temperature. The temperature-dependent resistivity ρ(T) reveals a clear signature of LA phonon scattering, yielding a deformation potential D=7.8±0.5 eV.