Insulating Electronic States Near the Dirac Point Arising from Twisted Stacking and Curvature in 3D Nanoporous Graphene

Abstract

Twist-stacked graphene with a twist angle $\theta$ of $\sim 5^{\circ }$--$30^{\circ }$ retains two-dimensional monolayer graphene-like Dirac states near the Dirac point. In three-dimensional nanoporous graphene (3D-NPG), curvature inherently produces twist-stacking and topological defects required to form a porous network. When regions with $\theta \ge 5^{\circ }$ dominate, Dirac states in individual layers are expected to persist, allowing the Dirac-electron behavior to be tuned through coupling to the 3D curved geometry. However, predicted band gap formation or localized states have remained unobserved. Here we report that 3D-NPG maintains monolayer-like Dirac electronic states while simultaneously exhibiting insulating behavior near the Dirac point. Raman G-band softening confirms these monolayer-like states, and an Arrhenius-type temperature-resistance trend coexisting with weak localization near the Dirac point indicates partially insulating states induced by topological defects. These findings demonstrate that 3D-NPG hosts distinctive Dirac electronic states coupled to 3D curvature, providing a platform for developing new functionalities in 3D graphene-based electronics and energy devices.

30 pages, 5 figures, and supplementary material. The final published version will appear in Carbon

References in corpus (27)

• The electronic properties of graphene
• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Raman spectroscopy as a versatile tool for studying the properties of graphene
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Quantifying defects in graphene via Raman spectroscopy at different excitation energies
• Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering
• Moire bands in twisted double-layer graphene
• Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
• Energy gaps, topological insulator state and zero-field quantum Hall effect in graphene by strain engineering
• Born-Oppenheimer Breakdown in Graphene
• Asymmetry gap in the electronic band structure of bilayer graphene
• Electric Field Effect Tuning of Electron-Phonon Coupling in Graphene
• Measurement of Scattering Rate and Minimum Conductivity in Graphene
• Weak localisation magnetoresistance and valley symmetry in graphene
• Magic Angle Spectroscopy
• Single Layer Behavior and Its Breakdown in Twisted Graphene Layers
• Lattice relaxation and energy band modulation in twisted bilayer graphenes
• Non-adiabatic Kohn-anomaly in a doped graphene monolayer
• Raman Spectroscopy of Electrochemically-Gated Graphene Transistors: Geometrical Capacitance, Electron-Phonon, Electron-Electron, and Electron-Defect Scattering
• Quasicrystalline electronic states in 30${}^{\circ }$ rotated twisted bilayer graphene
• Pseudo-magnetic field in curved graphene
• Three-dimensional porous graphene networks expand graphene-based electronic device applications
• Electric Properties of Dirac Fermions Captured into 3D Nanoporous Graphene Networks
• Band dispersion of graphene with structural defects
• Dirac Fermion kinetics in three-dimensionally curved graphene
• Gap opening in topological-defect lattices in graphene
• Optical Phonons in Twisted Bilayer Graphene with Gate-Induced Asymmetric Doping