Article
Chemistry, Multidisciplinary
Penghui Ji, Oliver MacLean, Gianluca Galeotti, Dominik Dettmann, Giulia Berti, Kewei Sun, Haiming Zhang, Federico Rosei, Lifeng Chi
Summary: This study systematically investigates the effects of oxygen on the synthesis of 3p-AGNRs, revealing a strong catalytic effect that reduces reaction temperature without degradation of the AGNRs. Utilizing Ullmann-type coupling on Cu(111), poly(para-phenylene) (3-AGNR) was synthesized and converted into wider 3p-AGNRs through lateral fusion. Scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy confirmed the formation of different ribbons, with regions of increased STM contrast attributed to the intercalation of Br atoms during lateral fusion.
SCIENCE CHINA-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Mark J. Haastrup, Mathias H. R. Mammen, Jonathan Rodriguez-Fernandez, Jeppe Lauritsen
Summary: The study investigates the lateral interfaces formed between monolayer MoS2 flakes on Au(111) and two families of armchair graphene nanoribbons (GNRs) created through on-surface assisted Ullmann coupling. The findings show that parallel alignment between GNR armchair edges and MoS2 leads to van der Waals bonded nanoribbons, while a perpendicular orientation results in covalent bonding between a phenyl group of GNR and S on the edge. The presence of MoS2 lowers the temperatures needed for intramolecular dehydrogenation during GNR formation, leading to enhanced hydrogen recombination at the MoS2 edges.
Article
Chemistry, Multidisciplinary
Alejandro Berdonces-Layunta, Fabian Schulz, Fernando Aguilar-Galindo, James Lawrence, Mohammed S. G. Mohammed, Matthias Muntwiler, Jorge Lobo-Checa, Peter Liljeroth, Dimas G. de Oteyza
Summary: The development of on-surface chemistry under vacuum has significantly enhanced our ability to synthesize carbon nanomaterials with atomic precision, particularly graphene nanoribbons. A detailed study of the growth process of armchair GNRs starting from dibromoperylene reveals a unique reaction pathway that can guide the design of other precursor molecules. Precursor molecules couple through a concerted mechanism to form covalent bonds and undergo dehydrogenation simultaneously, leading to straight GNR growth despite the presence of irregular metal-organic intermediates.
Article
Chemistry, Physical
Yifei Yang, Limei Wang, Zhenyu Zhang, Ping Cui
Summary: A kinetic pathway for growing the narrowest zigzag graphene nanoribbons (nZGNRs) on Cu(111) using specific precursor molecules is proposed in this study through first-principles calculations. The precursor molecule readily adsorbs and reacts on the substrate, exhibiting high diffusional and rotational mobilities during the formation process. The study also demonstrates that proper substrate choices can enhance the yield of nZGNRs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Xiao Guo, Qiwei Tian, Yongsong Wang, Jinxin Liu, Guiping Jia, Weidong Dou, Fei Song, Lijie Zhang, Zhihui Qin, Han Huang
Summary: Graphene nanoribbons (GNRs) are a potential alternative to graphene with gaps, and have been used in next-generation nanoelectronic devices. Research has found that temperature affects the frequency of G mode and RBLM, and the temperature coefficient of 7-AGNR is relatively high.
Article
Chemistry, Multidisciplinary
Thi Thuy Nhung Nguyen, Stephen R. Power, Hrag Karakachian, Ulrich Starke, Christoph Tegenkamp
Summary: This study investigates the impact of edge and width variations of graphene nanoribbons on quantum confinement effects. The researchers found that regardless of the ribbon width, the band gaps near the edges of the nanoribbons are significantly reduced, and edge passivation plays a crucial role in determining the local electronic properties of epitaxial nanoribbons.
Article
Chemistry, Physical
Yifan Zhang, Kecheng Cao, Takeshi Saito, Hiromichi Kataura, Hans Kuzmany, Thomas Pichler, Ute Kaiser, Guowei Yang, Lei Shi
Summary: This study investigated the diameter-dependent synthesis of GNRs using SWCNTs of different average diameters, and found that the width of GNRs can be tailored by the diameter of SWCNTs. Particularly, SWCNTs with an average diameter of 1.3 nm produced the highest yield of 6 and 7 armchair GNRs, indicating potential for high-yield production of certain GNRs in large scale applications.
Article
Chemistry, Multidisciplinary
Elie Geagea, Judicael Jeannoutot, Louise Morgenthaler, Simon Lamare, Alain Rochefort, Frank Palmino, Frederic Cherioux
Summary: The growth of graphene nanoribbons on a Cu(111) surface by thermal annealing of 9,9'-bianthryl derivatives was re-investigated using scanning tunnelling microscopy. The proposal of an intramolecular hydrogen atom transfer as a key-step in the formation of (3,1)-graphene nanoribbons on the Cu(111) surface was based on the results obtained.
CHEMICAL COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Yuriy G. Pogorelov, Vadim M. Loktev
Summary: In this study, the effects of impurities on specific Dirac-like modes in finite ribbons of graphene with armchair edges are examined in detail. Using the Anderson hybrid model of impurity perturbation, the possibility of Mott localization and the opening of a mobility gap under local impurity perturbations are investigated. The analysis considers various model parameters such as the impurity energy level, its hybridization with the host Dirac modes, and the impurity concentration. Special attention is given to the interplay between impurity disorder and spin-orbit splitting of the host spectrum for potential tunable metal-insulator phase transitions.
Article
Chemistry, Physical
Aristides D. Zdetsis
Summary: A new and unusual type of constructive quantum interference (CQI) is revealed in selected isolated armchair graphene nanoribbons (AGNRs). The study found that the topological properties of AGNRs undergo a phase transition within a certain length range, and CQI characteristics appear at a specific length.
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
Chemistry, Multidisciplinary
Saiyu Bu, Yao Chen, Debra J. Searles, Qinghong Yuan
Summary: Crystal domain alignment is crucial for the synthesis of large, single-crystal, two-dimensional materials. However, achieving the alignment has remained unclear. In this study, a physical model and first principles calculations were used to explain the lack of alignment in graphene domains grown on the Cu(111) surface. It was found that small hexagonal graphene domains are always misaligned on the substrate due to preferred binding sites. Only when the domains reach a certain size, near-perfect alignment can be achieved. The results highlight the importance of low nucleation density for epitaxial alignment of graphene domains on Cu(111) surfaces.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Florentino Lopez-Urias, Josue Ortiz-Medina
Summary: Using first-principles density functional theory calculations, the properties of armchair graphene nanoribbons (AGNRs) and graphene with an extended line defect (ELD) were investigated. The authors discovered that AGNRs with a 4-8-ELD exhibit metallic behavior, and graphene with 4-8-ELDs is also metallic compared to pristine graphene. This study provides a theoretical basis for tailoring graphene structures with potential applications in electronic devices.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Chemistry, Physical
Shijie Sun, Yurou Guan, Zhenliang Hao, Zilin Ruan, Hui Zhang, Jianchen Lu, Lei Gao, Xiaoqing Zuo, Jinming Cai
Summary: Graphene nanoribbons (GNRs) exhibit superior properties and tunability in electronic properties, with bandgaps depending on width and edges. The narrow sn-8AGNR can effectively regulate the bandgap in electronic structures.
Article
Chemistry, Physical
Gesiel G. Silva, Wiliam F. da Cunha, Marcelo L. Pereira Junior, Luiz F. Roncaratti, Luiz A. Ribeiro Junior
Summary: Our investigation on bipolaron dynamics in armchair graphene nanoribbons (AGNRs) reveals that in different electric fields and electron-phonon coupling regimes, bipolarons in narrower AGNRs move as fast as those in conjugated polymers, shedding light on the behavior of charge carriers in graphene nanoribbons.
CHEMICAL PHYSICS LETTERS
(2021)
