Article
Physics, Multidisciplinary
Nikita V. Tepliakov, Johannes Lischner, Efthimios Kaxiras, Arash A. Mostofi, Michele Pizzochero
Summary: In this study, a new perspective on the electronic structure of armchair graphene nanoribbons is presented using simple model Hamiltonians and ab initio calculations. The research demonstrates that the energy-gap opening in these nanoribbons is caused by the breaking of a hidden symmetry through long-ranged hopping of pi electrons and structural distortions at the edges. This hidden symmetry can be restored or manipulated through in-plane lattice strain, enabling continuous energy-gap tuning, the emergence of Dirac points at the Fermi level, and topological quantum phase transitions. This work establishes an original interpretation of the semiconducting properties of armchair graphene nanoribbons and provides guidelines for their rational electronic structure design.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Xi Wu, Fawei Zheng, Feiyu Kang, Jia Li
Summary: By using density functional theory calculations, we have identified the stable intercalated structure and the evolution of band structures in the intercalation process of Li into bilayer graphene. Our work shows that the Dirac cone of bilayer graphene can be modulated by using the generalized N/ N/ Kekule order, which opens a gap or splits the electron and hole pocket, contributed by the Kekule-O and Kekule-Y distortion respectively. This study provides valuable insights for the investigation of Li-intercalated bilayer graphene in experiments.
Article
Chemistry, Physical
Michele Pizzochero, Efthimios Kaxiras
Summary: This study investigates armchair graphene nanoribbons with asymmetric edge extensions consisting of laterally fused naphtho groups, showing tunability of pi-magnetism induced by naphtho groups. These structures exhibit full spin-polarization at band extrema and the ferromagnetic ground state can be manipulated into nonmagnetic or antiferromagnetic phases through external stimuli. This work establishes these one-dimensional architectures as suitable platforms for logic spintronics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Fereshte Ildarabadi, Rouhollah Farghadan
Summary: Researchers found that applying nonuniform strain in zigzag graphene nanoribbons can generate spin-thermoelectric effects, leading to a tunable spin-dependent band gap, pure spin current, and a giant spin Seebeck coefficient. This provides a practical pathway for improved design in spin-thermoelectric applications through strain engineering.
Article
Chemistry, Multidisciplinary
Luis M. Mateo, Qiang Sun, Kristjan Eimre, Carlo A. Pignedoli, Tomas Torres, Roman Fasel, Giovanni Bottari
Summary: On-surface synthesis is a powerful tool for constructing large, planar, pi-conjugated structures that are inaccessible through standard solution chemistry, with graphene nanoribbons (GNRs) holding a prime position in nanoelectronics due to their outstanding properties. Using appropriately designed molecular precursors allows the synthesis of functionalized GNRs, leading to nanostructured hybrids with superior physicochemical properties. Porphyrins (Pors) stand out among potential partners for GNRs due to their rich chemistry, robustness, and electronic richness, but constructing GNR hybrids with such pi-conjugated macrocycles is challenging and examples are scarce.
Article
Chemistry, Multidisciplinary
Ethan Chi Ho Wen, Peter H. Jacobse, Jingwei Jiang, Ziyi Wang, Steven G. Louie, Michael F. Crommie, Felix R. Fischer
Summary: Substitutional heteroatom doping in 1D graphene nanoribbons is a versatile tool for low-dimensional functional materials, but previous methods only result in modest realignment of energy levels. This study introduces nitrogen core-doped armchair GNRs that yield greater energy-level shifting through the substitution of carbon atoms with nitrogen atoms along the backbone.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Natalia Cortes, Oscar Negrete, Francisco J. Pena, Patricio Vargas
Summary: The electrocaloric effect in graphene structures can be influenced by external electric fields, with different stacking arrangements resulting in different thermal responses. In certain stacking configurations, both direct and inverse electrocaloric responses may occur within the same sample.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Boris Senkovskiy, Alexey Nenashev, Seyed K. Alavi, Yannic Falke, Martin Hell, Pantelis Bampoulis, Dmitry Rybkovskiy, Dmitry Yu Usachov, Alexander Fedorov, Alexander Chernov, Florian Gebhard, Klaus Meerholz, Dirk Hertel, Masashi Arita, Taichi Okuda, Koji Miyamoto, Kenya Shimada, Felix R. Fischer, Thomas Michely, Sergei D. Baranovskii, Klas Lindfors, Thomas Szkopek, Alexander Grueneis
Summary: The study synthesized a monolayer of graphene nanoribbons with multiple aligned heterojunctions, and characterized them using various methods, showing that charge transport is controlled by potential barriers formed by wide-bandgap GNR segments.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Rayan Chakraborty, Tariq Sheikh, Angshuman Nag
Summary: The study of two-dimensional layered hybrid perovskites reveals that the new iodine-iodine interaction and hydrogen bonding can influence the crystal structure and optical properties. The symmetry of hydrogen bonding has a significant impact on band gap and bond angles.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Physical
Can Wang, Kaili Wang, Huaiqiang Wang, Qichao Tian, Junyu Zong, Xiaodong Qiu, Wei Ren, Li Wang, Fang-Sen Li, Wei-Bing Zhang, Haijun Zhang, Yi Zhang
Summary: Superlattice potentials imposed on graphene can alter its Dirac states, enabling the realization of various quantum phases. We experimentally observed a replica Dirac cone at the Brillouin zone center induced by a superlattice in heavily doped graphene with Gd intercalation using angle-resolved photoemission spectroscopy (ARPES). The replica Dirac cone arises from the (root 3x root 3)R30 degrees superlattice formed by the intervalley coupling of two nonequivalent valleys, accompanied by a bandgap opening. The modulation of the replica Dirac band is primarily attributable to the residual frozen gas, which can act as a source of intervalley scattering at temperatures below 30 K. Our results highlight the persistence of the hidden Kekule'-like phase within heavily doped graphene, enriching our current understanding of its replica Dirac Fermions.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Engineering, Electrical & Electronic
H. M. Abd El-daim, F. A. Taher, N. S. Morsy, G. M. Turky, A. A. Ali
Summary: Through surface modification with reduced graphene oxide (rGO), pure and blend fabrics showed enhanced electrical conductivity, making them suitable for various potential applications in smart textiles, such as sensing, energy storage, and conversion devices.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Materials Science, Multidisciplinary
Lanting Feng, Zhe Liu, Mingfeng Zhu, Yisong Zheng
Summary: The conductivity of ABA-stacked trilayer graphene is smaller than that of monolayer graphene due to strong interband scattering. This is despite the fact that the trilayer graphene has an additional parabolic dispersion band.
Article
Nanoscience & Nanotechnology
Alina Valimukhametova, Conor Ryan, Thomas Paz, Fabian Grote, Anton Naumov
Summary: Graphene oxide (GO) is a promising nanomaterial for optoelectronic applications due to its fluorescence and beneficial physical properties. While other graphene derivatives are possible, GO remains the most heavily used. This study explores different graphene derivatives and their optical properties, proposing a unified model for optical emission. The research suggests that graphene derivatives have minimal dependence on functional groups for their optical properties, indicating potential for use in research and industry.
Article
Chemistry, Multidisciplinary
Yanren Cao, Haiyan Li, Jingyi Jin, Yanxin Li, Ting Feng, Wei Wang, Bohua Dong, Lixin Cao
Summary: Utilizing the (CuIn)(x)Zn2(1-x)S2 solid solution photocatalyst and co-catalyst a-MoSx can effectively enhance the performance of photocatalytic water splitting, achieving a hydrogen evolution rate of 2100 µmol g-1 h-1.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
A. Kochaev, M. Maslov, K. Katin, V. Efimov, I. Efimova
Summary: Unilateral surface passivation by hydrogen atoms is an effective method to stabilize borophene-graphene with periodic perforation. Without hydrogen, a transition from porous graphene to graphenylene is observed. In the H-passivated porous borophene-graphene, covalent and van der Waals forces act between boron and carbon layers. Ab initio calculations confirm the stability through cohesive energy and phonon spectrum. The electronic properties show semiconductor nature mainly due to boron sites. The elasticity response is weaker than borophene-graphene, but the out-of-plane piezoelectric effect is stronger. Optical properties, especially absorption peak values in the optical range, are of particular interest.
MATERIALS TODAY NANO
(2022)
