On‐Surface Synthesis of a Nitrogen‐Doped Graphene Nanoribbon with Multiple Substitutional Sites

Abstract Doped graphene nanoribbons (GNRs) with heteroatoms are a principal strategy to fine‐tune the electronic structures of GNRs for future device applications. Here, we successfully synthesized the N=9 nitrogen‐doped armchair GNR on the Au(111) surface. Due to the flexibility of precursor molecules, three different covalent bonds (C−C, C−N, N−N) are formed in the GNR backbone. Scanning tunneling spectroscopy analysis together with band structure calculations reveals that the band gap of the N‐9‐AGNRs (C−C) will be enlarged compared to pristine 9‐AGNRs, and the C−N bond and N−N bond at the isolated site of N‐9‐AGNR (C−C) will introduce new defect states near the Fermi level. DFT calculations reveal that the electronic structure of N‐9‐AGNR (C−C) shows semiconductor character, while N‐9‐AGNR (C−N) and N‐9‐AGNR (N−N) display metallic character. Our results provide a promising route for creating more complex molecular heterostructures with tunable band gaps, which may be useful for future molecular electronics and memory device applications.