Zhao Yan, Kang Li-Xia, Wang Yi-Jun, Wu Yi, Xing Guang-Yan, Li Shi-Wen, Pan Jinliang, Wang Nie-Wei, Ren Yin-Ti, Wang Ying, Zhu Ya-Cheng, Shi Xing-Qiang, Liu Mengxi, Qiu Xiaohui, Liu Pei-Nian, Li Deng-Yuan
State Key Laboratory of Natural Medicines, School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, China.
School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China.
Angew Chem Int Ed Engl. 2025 Jun 26:e202500490. doi: 10.1002/anie.202500490.
Heteroatom doping is an important method for engineering graphene nanoribbons (GNRs) because of its ability to modify electronic properties by introducing extra electrons or vacancies. However, precisely integrating oxygen atoms into the lattice of GNRs is unexplored, and the resulting electronic properties remain elusive. Here, we achieve the precise embedding of oxygen atoms into the lattice of GNRs via in situ formation of pyrans, synthesizing two types of oxygen-doped GNRs (O-doped chevron-GNR and O-doped chiral (2,1)-GNR). Using scanning tunneling microscopy, noncontact atomic force microscopy, and density functional theory calculations, the atomic structures and electronic properties of O-doped GNRs are determined, demonstrating that both GNRs are direct bandgap semiconductors with different sensitivities to oxygen dopants. Oxygen dopants have a minor impact on the bandgap of chevron-GNR but a significant effect on the bandgap of chiral (2,1)-GNR, which is attributed to the difference in density of states near the Fermi level between substituted intrinsic carbon atoms and their pristine counterparts. Compared with the pristine chiral (2,1)-GNR, the band structure of O-doped chiral (2,1)-GNR exhibits unexpected band edges transition, which is ascribed to sp-hybridized oxygen atoms which introduces additional electrons to the conduction band of chiral (2,1)-GNR, leading to the upward shift of Fermi surface.
杂原子掺杂是调控石墨烯纳米带（GNRs）的一种重要方法，因为它能够通过引入额外电子或空位来改变电子性质。然而，将氧原子精确地整合到GNRs晶格中的方法尚未被探索，其产生的电子性质也仍然难以捉摸。在此，我们通过原位形成吡喃，实现了氧原子在GNRs晶格中的精确嵌入，合成了两种类型的氧掺杂GNRs（氧掺杂的人字形GNR和氧掺杂的手性(2,1)-GNR）。利用扫描隧道显微镜、非接触原子力显微镜和密度泛函理论计算，确定了氧掺杂GNRs的原子结构和电子性质，表明这两种GNRs都是对氧掺杂剂具有不同敏感性的直接带隙半导体。氧掺杂剂对人字形GNR的带隙影响较小，但对手性(2,1)-GNR的带隙有显著影响，这归因于取代的本征碳原子与其原始对应物之间费米能级附近的态密度差异。与原始的手性(2,1)-GNR相比，氧掺杂的手性(2,1)-GNR的能带结构表现出意想不到的能带边缘跃迁，这归因于sp杂化的氧原子，它将额外的电子引入到手性(2,1)-GNR的导带中，导致费米面向上移动。
