Nonlinear photocurrents in two-dimensional systems based on graphene and boron nitride

Abstract

DC photoelectrical currents can be generated purely as a non-linear effect in uniform media lacking inversion symmetry without the need for a material junction or bias voltages to drive it, in what is termed photogalvanic effect. These currents are strongly dependent on the polarization state of the radiation, as well as on topological properties of the underlying Fermi surface such as its Berry curvature. In order to study the intrinsic photogalvanic response of gapped graphene (GG), biased bilayer graphene (BBG), and hexagonal boron nitride (hBN), we compute the non-linear current using a perturbative expansion of the density matrix. This allows a microscopic description of the quadratic response to an electromagnetic field in these materials, which we analyze as a function of temperature and electron density. We find that the intrinsic response is robust across these systems and allows for currents in the range of pA cm/W to nA cm/W. At the independent-particle level, the response of hBN-based structures is significant only in the ultra-violet due to their sizeable band-gap. However, when Coulomb interactions are accounted for by explicit solution of the Bethe-Salpeter equation, we find that the photoconductivity is strongly modified by transitions involving exciton levels in the gap region, whose spectral weight dominates in the overall frequency range. Biased bilayers and gapped monolayers of graphene have a strong photoconductivity in the visible and infrared window, allowing for photocurrent densities of several nA cm/W. We further show that the richer electronic dispersion of BBG at low energies and the ability to change its band-gap on demand allows a higher tunability of the photocurrent, including not only its magnitude but also, and significantly, its polarity.

Updating with published version and respective references; 14 pages, 11 figures

References in corpus (23)

• Boron nitride substrates for high-quality graphene electronics
• Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering
• Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
• Measurement of the Optical Conductivity of Graphene
• Commensurate-incommensurate transition for graphene on hexagonal boron nitride
• The optical conductivity of graphene in the visible region of the spectrum
• Excitonic Effects on the Optical Response of Graphene and Bilayer Graphene
• Photo-excitation Cascade and Multiple Carrier Generation in Graphene
• Spectroscopic ellipsometry of graphene and an exciton-shifted van Hove peak in absorption
• Ultrafast Photoluminescence from Graphene
• Ballistic transport exceeding 28 μm in CVD grown graphene
• Energy gap tuning in graphene on hexagonal boron nitride bilayer system
• Stability of boron nitride bilayers: Ground state energies, interlayer distances, and tight-binding description
• Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures
• Conductivity of suspended and non-suspended graphene at finite gate voltage
• Band gaps in incommensurable graphene on hexagonal boron nitride
• Tunable Excitons in Biased Bilayer Graphene
• Graphene on Hexagonal Boron Nitride
• Tuning many-body interactions in graphene: The effects of doping on excitons and carrier lifetimes
• Effect of Holstein phonons on the electronic properties of graphene
• Graphene Transport at High Carrier Densities using a Polymer Electrolyte Gate
• The infrared conductivity of graphene
• Electrically tunable resonant scattering in fluorinated bilayer graphene

Cited by in corpus (25)

• Ultra-strong nonlinear optical processes and trigonal warping in MoS${}_2$ layers
• Imperfect Recollisions in High-Harmonic Generation in Solids
• Nonlinear optical responses of crystalline systems: Results from a velocity gauge analysis
• Linear and nonlinear optical response of crystals using length and velocity gauges: Effect of basis truncation
• Basis-Independent Spectral Methods for Non-linear Optical Response in Arbitrary Tight-binding Models
• Absorption of single-layer hexagonal boron nitride in the ultraviolet
• Terahertz photogalvanics in twisted bilayer graphene close to the second magic angle
• Gauge invariance of excitonic linear and nonlinear optical response
• Edge photocurrent driven by THz electric field in bi-layer graphene
• Nonlinear optical response of doped mono- and bilayer graphene: length gauge tight-binding model
• Quantum Theory of Nonlinear Thermal Response
• Second harmonic spectroscopy to optically detect valley polarization in 2D materials
• Equivalence of semiclassical and response theories for second-order nonlinear ac Hall effects
• Optical third harmonic generation in black phosphorus
• Highly superlinear photogalvanic effects in (Bi${}_{0.3}$Sb${}_{0.7}$)${}_2$(Te${}_{0.1}$Se${}_{0.9}$)${}_3$: Probing 3D topological insulator surface states at room temperature
• Atomic configuration controlled photocurrent in van der Waals homostructures
• Cavity-induced charge transfer in periodic systems: length-gauge formalism
• Expeditious computation of nonlinear optical properties of arbitrary order with native electronic interactions in the time domain
• A study of the nonlinear optical response of the plain graphene and gapped graphene monolayers beyond the Dirac approximation
• Detection of quantum geometric tensor by nonlinear optical response
• Topological zero-modes of the spectral localizer of trivial metals
• Moiré amplification of highly tunable shift current response in twisted trilayer graphene
• Trigonal warping effects on optical properties of anomalous Hall materials
• Shift current in 2D Janus Transition-Metal Dichalcogenides: the role of excitons
• Berry: A code for the differentiation of Bloch wavefunctions from DFT calculations