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 (CÀ C, CÀ N, NÀ 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 (CÀ C) will be enlarged compared to pristine 9-AGNRs, and the CÀ N bond and NÀ N bond at the isolated site of N-9-AGNR (CÀ C) will introduce new defect states near the Fermi level. DFT calculations reveal that the electronic structure of N-9-AGNR (CÀ C) shows semiconductor character, while N-9-AGNR (CÀ N) and N-9-AGNR (NÀ 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.

Rational Regulation of the Exciton Effect of Acrylonitrile-Linked Covalent Organic Framework toward Boosting Visible-Light-Driven Hydrogen Evolution

“…52 TP-BPyN COF and TP-BPyN PCOF both present a further tiny blue shift than that of TP-BPN COF, which could be related to the influence of the pyridine N atoms extending the bandgap of the COFs. 53 Based on UV−vis DRS, the band gaps were calculated from the Kubelka−Munk function. 54 Accordingly, the band gaps of TP-BPN COF, TP-PN COF, TP-BPyN COF, and TP-BPyN PCOF were 2.11, 1.96, 2.16, and 2.16 eV (Figure 3b), respectively.…”