Giant intrinsic photoresponse in pristine graphene
arXiv:1812.07111 · doi:10.1038/s41565-018-0323-8
Abstract
When the Fermi level matches the Dirac point in graphene, the reduced charge screening can dramatically enhance electron-electron (e-e) scattering to produce a strongly interacting Dirac liquid. While the dominance of e-e scattering already leads to novel behaviors, such as electron hydrodynamic flow, further exotic phenomena have been predicted to arise specifically from the unique kinematics of e-e scattering in massless Dirac systems. Here, we use optoelectronic probes, which are highly sensitive to the kinematics of electron scattering, to uncover a giant intrinsic photocurrent response in pristine graphene. This photocurrent emerges exclusively at the charge neutrality point and vanishes abruptly at non-zero charge densities. Moreover, it is observed at places with broken reflection symmetry, and it is selectively enhanced at free graphene edges with sharp bends. Our findings reveal that the photocurrent relaxation is strongly suppressed by a drastic change of fast photocarrier kinematics in graphene when its Fermi level matches the Dirac point. The emergence of robust photocurrents in neutral Dirac materials promises new energy-harvesting functionalities and highlights intriguing electron dynamics in the optoelectronic response of Dirac fluids.
arXiv commentOriginally submitted version
References in corpus (25)
- The electronic properties of graphene
- Electronic transport in two dimensional graphene
- Electron-Electron Interactions in Graphene: Current Status and Perspectives
- Hot Carrier-Assisted Intrinsic Photoresponse in Graphene
- Negative local resistance caused by viscous electron backflow in graphene
- Observation of the Dirac fluid and the breakdown of the Wiedemann-Franz law in graphene
- Photo-excitation Cascade and Multiple Carrier Generation in Graphene
- Photo-Thermoelectric Effect at a Graphene Interface Junction
- Ultrafast collinear scattering and carrier multiplication in graphene
- Photoconductivity of biased graphene
- Photocurrent measurements of supercollision cooling in graphene
- Quantum critical transport in clean graphene
- Quantum oscillations of the critical current and high-field superconducting proximity in ballistic graphene
- Slow imbalance relaxation and thermoelectric transport in graphene
- Non-equilibrium dynamics of photo-excited electrons in graphene: collinear scattering, Auger processes, and the impact of screening
- Spatially resolved edge currents and guided-wave electronic states in graphene
- Near-field photocurrent nanoscopy on bare and encapsulated graphene
- Photo-excited Carrier Dynamics and Impact Excitation Cascade in Graphene
- Competing Channels for Hot Electron Cooling in Graphene
- Shockley-Ramo theorem and long-range photocurrent response in gapless materials
- Dirac boundary condition at the reconstructed zigzag edge of graphene
- Slow noncollinear Coulomb scattering in the vicinity of the Dirac point in graphene
- Photo-Nernst current in graphene
- Current amplification and relaxation in Dirac systems
- Photoexcitation Cascade and Quantum-Relativistic Jets in Graphene
Cited by in corpus (10)
- Photocurrent as a multi-physics diagnostic of quantum materials
- Ultrafast intrinsic optical-to-electrical conversion dynamics in graphene photodetector
- Spatiotemporal Mapping of Photocurrent in a Monolayer Semiconductor Using a Diamond Quantum Sensor
- Visualizing bulk and edge photocurrent flow in anisotropic Weyl semimetals
- Anomalous Floquet tunneling in uniaxially strained graphene
- Switchable quantized conductance in topological insulators revealed by the Shockley-Ramo theorem
- Mapping the intrinsic photocurrent streamlines through micromagnetic heterostructure devices
- Dirac-point photocurrents due to photothermoelectric effect in non-uniform graphene devices
- Gate-Tunable Optical Nonlinearities and Extinction in Graphene/LaAlO/SrTiO Nanostructures
- Chiral transport of hot carriers in graphene in the quantum Hall regime