title: Graphene-like nanoribbons periodically embedded with four- and eight-membered rings.
abstract: Embedding non-hexagonal rings into sp2-hybridized carbon networks is considered a promising strategy to enrich the family of low-dimensional graphenic structures. However, non-hexagonal rings are energetically unstable compared to the hexagonal counterparts, making it challenging to embed non-hexagonal rings into carbon-based nanostructures in a controllable manner. Here, we report an on-surface synthesis of graphene-like nanoribbons with periodically embedded four- and eight-membered rings. The scanning tunnelling microscopy and atomic force microscopy study revealed that four- and eight-membered rings are formed between adjacent perylene backbones with a planar configuration. The non-hexagonal rings as a topological modification markedly change the electronic properties of the nanoribbons. The highest occupied and lowest unoccupied ribbon states are mainly distributed around the eight- and four-membered rings, respectively. The realization of graphene-like nanoribbons comprising non-hexagonal rings demonstrates a controllable route to fabricate non-hexagonal rings in nanoribbons and makes it possible to unveil their unique properties induced by non-hexagonal rings.
authors.affiliation: School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Meizhuang
authors.initials: M
authors.lastname: Liu
authors.affiliation: CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Liu
authors.affiliation: School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Limin
authors.initials: L
authors.lastname: She
authors.affiliation: CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Zeqi
authors.initials: Z
authors.lastname: Zha
authors.affiliation: CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Pan
authors.affiliation: CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Shichao
authors.initials: S
authors.lastname: Li
authors.affiliation: School of Chemistry, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Yangyong
authors.initials: Y
authors.lastname: He
authors.affiliation: School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Zeying
authors.initials: Z
authors.lastname: Cai
authors.affiliation: School of Chemistry, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Jiaobing
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Qiu
authors.affiliation: School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-Sen University, 510275 Guangzhou, China.
authors.forename: Dingyong
authors.initials: D
authors.lastname: Zhong