Hot electron transport in suspended multilayer graphene

Abstract

We study hot electron transport in short-channel suspended multilayer graphene devices created by a distinct experimental approach. For devices with semi-transparent contact barriers, a dip of differential conductance (dI/dV) has been observed at source drain bias Vd = 0, along with anomalies at higher Vd likely induced by optical phonon scattering. For devices with low contact barriers, only the dI/dV dip at Vd = 0 is observed, and we find a well-fit logarithmic dependence of dI/dV on both the bias Vd and the temperature T. The logarithmic Vd dependence is explained with the hot electron effect and the logarithmic T dependence could be attributed to the weak-localization in two-dimensions

Energy loss rates of hot Dirac fermions in epitaxial, exfoliated, and CVD graphene

“…19) but they could only be studied for electron temperatures up to 1.1 K. In our work the WL peak persists up to temperatures of almost 100 K, allowing a much more extensive range of parameters to be studied. Previous work in graphene, 26 however, was not able to determine energy loss rates from the damping of the WL peak.…”

Electronic properties of Au-graphene contacts

“…Similar fine structure has been observed in hot electron transport measurements on suspended multilayer graphene with semitransparent contact barriers. [22] It was suggested that the peaks at V = 0 arise from scattering from optical phonons. Stronger anomalies in conductance have also been observed in scanning tunneling spectroscopy in graphene, [23] and were attributed to the 67 meV out-of-plane acoustic graphene phonon modes located near the K/K' points in reciprocal space.…”

AB-Stacked Multilayer Graphene Synthesized via Chemical Vapor Deposition: A Characterization by Hot Carrier Transport

“…This dip feature vanishes gradually as the bias V increases. The similar behavior of the dI/dV as a function of T and V suggests the presence of electron heating, and the dI/dV dip can be related to the hot electron effect 16,24,25 as explained below. At finite bias, the energy supplied to the charge carriers by the electric field cannot be transferred to the lattice fast enough due to a relatively weak electron-phonon scattering at low temperatures, resulting in an effective electron temperature T e higher than the lattice temperature T l (same as the cryostat temperature T in experiments).…”

“…We further observed that magnetic fields attenuate the hot electron effect and thus provide a way for its control by enhancing cyclotron-phonon scattering. 16,17…”