Hot electron cooling by acoustic phonons in graphene

Abstract

We have investigated the energy loss of hot electrons in metallic graphene by means of GHz noise thermometry at liquid helium temperature. We observe the electronic temperature T / V at low bias in agreement with the heat diffusion to the leads described by the Wiedemann-Franz law. We report on $T\propto \sqrt{V}$ behavior at high bias, which corresponds to a T4 dependence of the cooling power. This is the signature of a 2D acoustic phonon cooling mechanism. From a heat equation analysis of the two regimes we extract accurate values of the electron-acoustic phonon coupling constant $\Sigma$ in monolayer graphene. Our measurements point to an important effect of lattice disorder in the reduction of $\Sigma$, not yet considered by theory. Moreover, our study provides a strong and firm support to the rising field of graphene bolometric detectors.

5 figures

References in corpus (10)

• The electronic properties of graphene
• Boron nitride substrates for high-quality graphene electronics
• Temperature dependent transport in suspended graphene
• Electron-phonon heat transfer in monolayer and bilayer graphene
• Wedging Transfer of Nanostructures
• Shot Noise with Interaction Effects in Single Walled Carbon Nanotubes
• Transport scattering time probed through rf admittance of a graphene capacitor
• Electron heating in metallic resistors at sub-Kelvin temperature
• Electron-phonon coupling in single walled carbon nanotubes determined by shot noise
• Thermal shot noise in top-gated single carbon nanotube field effect transistors

Cited by in corpus (9)

• Supercollision cooling in undoped graphene
• Hot-electron cooling by acoustic and optical phonons in monolayers of MoS${}_2$ and other transition-metal dichalcogenides
• Electron-phonon mediated heat flow in disordered graphene
• Energy Flows in Graphene: Hot Carrier Dynamics and Cooling
• Hot-Carrier Seebeck Effect: Diffusion and Remote Detection of Hot Carriers in Graphene
• Hot carrier relaxation of Dirac fermions in bilayer epitaxial graphene
• Normal Metal Hot-Electron Nanobolometer with Johnson Noise Thermometry Readout
• Monolayer graphene bolometer as a sensitive far-IR detector
• Observation of vacancy-induced suppression of electronic cooling in defected graphene