Modeling of Temperature and Field-Dependent Electron Mobility in a Single-Layer Graphene Sheet

摘要

In this paper, we address a physics-based analytical model of electric-field-dependent electron mobility $(mu)$ in a single-layer graphene sheet using the formulation of Landauer and Mc Kelvey's carrier flux approach under finite temperature and quasi-ballistic regime. The energy-dependent, near-elastic scattering rate of in-plane and out-of-plane (flexural) phonons with the electrons are considered to estimate $mu$ over a wide range of temperature. We also demonstrate the variation of $mu$ with carrier concentration as well as the longitudinal electric field. We find that at high electric field $({>}10^{6}~{rm Vm}^{-1})$, the mobility falls sharply, exhibiting the scattering between the electrons and flexural phonons. We also note here that under quasi-ballistic transport, the mobility tends to a constant value at low temperature, rather than in between $T^{-2}$ and $T^{-1}$ in strongly diffusive regime. Our analytical results agree well with the available experimental data, while the methodologies are put forward to estimate the other carrier-transmission-dependent transport properties.