Competing Channels for Hot Electron Cooling in Graphene

Abstract

We report on temperature dependent photocurrent measurements of high-quality dual-gated monolayer graphene (MLG) p-n junction devices. A photothermoelectric (PTE) effect governs the photocurrent response in our devices, allowing us to track the hot electron temperature and probe hot electron cooling channels over a wide temperature range (4 K to 300 K). At high temperatures ($T>T^{\ast }$), we found that both the peak photocurrent and the hot spot size decreased with temperature, while at low temperatures ($T<T^{\ast }$), we found the opposite, namely that the peak photocurrent and the hot spot size increased with temperature. This non-monotonic temperature dependence can be understood as resulting from the competition between two hot electron cooling pathways: (a) (intrinsic) momentum-conserving normal collisions (NC) that dominates at low temperatures and (b) (extrinsic) disorder-assisted supercollisions (SC) that dominates at high temperatures. Gate control in our high quality samples allows us to resolve the two processes in the same device for the first time. The peak temperature $T^{\ast }$ depends on carrier density and disorder concentration, thus allowing for an unprecedented way of controlling graphene's photoresponse.

arXiv comment5 pages, 4 figures

References in corpus (26)

• Hot Carrier-Assisted Intrinsic Photoresponse in Graphene
• Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
• Measurement of Ultrafast Carrier Dynamics in Epitaxial Graphene
• Ultrafast Optical-Pump Terahertz-Probe Spectroscopy of the Carrier Relaxation and Recombination Dynamics in Epitaxial Graphene
• Transport measurements across a tunable potential barrier in graphene
• Photo-excitation Cascade and Multiple Carrier Generation in Graphene
• Photo-Thermoelectric Effect at a Graphene Interface Junction
• Photocurrent imaging and efficient photon detection in a graphene transistor
• Substrate limited electron dynamics in graphene
• Hot Carrier Transport and Photocurrent Response in Graphene
• Electronic transport and quantum Hall effect in bipolar graphene p-n-p junction
• Anomalous thermoelectric transport of Dirac particles in graphene
• The role of contacts in graphene transistors: A scanning photocurrent study
• Photocurrent measurements of supercollision cooling in graphene
• Disorder-Assisted Electron-Phonon Scattering and Cooling Pathways in Graphene
• Carrier dynamics in epitaxial graphene close to the Dirac point
• Electronic Cooling in Graphene
• Electron-phonon heat transfer in monolayer and bilayer graphene
• Supercollision cooling in undoped graphene
• Very Slow Cooling Dynamics of Photoexcited Carriers in Graphene Observed by Optical-Pump Terahertz-Probe Spectroscopy
• Slowing hot carrier relaxation in graphene using a magnetic field
• Thermoelectric imaging of structural disorder in epitaxial graphene
• Surface polar optical phonon interaction induced many-body effects and hot-electron relaxation in graphene
• Transient absorption and photocurrent microscopy show hot electron supercollisions describe the rate-limiting relaxation step in graphene
• Coulomb Drag Mechanisms in Graphene
• Energy-driven Drag at Charge Neutrality in Graphene

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