Boron-Doped Graphene Nanoribbons: Electronic Structure and Raman Fingerprint

We show that strong chemical interaction between boron doped graphene nanoribbons with N = 7 atoms width (B-7AGNRs) and an Au substrate leads to periodic out-of-plane corrugation and electron doping of B-7AGNRs. Using angle-resolved photoemission spectroscopy (ARPES), we find that the dopant-derived bands hybridize with substrate electronic states and spread in energy. The interaction with the substrate leaves the bands with pure carbon character unperturbed. This results in an identical effectives mass of ∼ 0.2 m0 compared to pristine 7AGNRs. The presence of boron atoms further manifests in the vibrational properties. We probe the phonons of B-7AGNRs in situ by Raman spectroscopy. We reveal the existence of characteristic splittings and red-shifts of Raman modes due to the presence of C-B bonds. The strongly hybridized electronic structure of the B-7AGNR - Au contact can be useful for carbon based nanoelectronics. The Raman fingerprint allows easy identification in device geometries