Boron-Doped Graphene Nanoribbons: Electronic Structure and Raman Fingerprint.
Boris V SenkovskiyDmitry Yu UsachovAlexander V FedorovTomas MarangoniDanny HabererCesare TrescaGianni ProfetaVasile CaciucShigeru TsukamotoNicolae AtodireseiNiels EhlenChaoyu ChenJosé AvilaMaria Carmen AsensioAndrei Yu VarykhalovAlexei NefedovChristof WöllTimur K KimMoritz HoeschFelix R FischerAlexander GrüneisPublished in: ACS nano (2018)
We investigate the electronic and vibrational properties of bottom-up synthesized aligned armchair graphene nanoribbons of N = 7 carbon atoms width periodically doped by substitutional boron atoms (B-7AGNRs). Using angle-resolved photoemission spectroscopy and density functional theory calculations, we find that the dopant-derived valence and conduction band states are notably hybridized with electronic states of Au substrate and spread in energy. The interaction with the substrate leaves the bands with pure carbon character rather unperturbed. This results in an identical effective mass of ≈0.2 m0 for the next-highest valence band compared with pristine 7AGNRs. We probe the phonons of B-7AGNRs by ultrahigh-vacuum (UHV) Raman spectroscopy and reveal the existence of characteristic splitting and red shifts in Raman modes due to the presence of substitutional boron atoms. Comparing the Raman spectra for three visible lasers (red, green, and blue), we find that interaction with gold suppresses the Raman signal from B-7AGNRs and the energy of the green laser (2.33 eV) is closer to the resonant E22 transition. The hybridized electronic structure of the B-7AGNR-Au interface is expected to improve electrical characteristics of contacts between graphene nanoribbon and Au. The Raman fingerprint allows the easy identification of B-7AGNRs, which is particularly useful for device fabrication.
Keyphrases
- raman spectroscopy
- density functional theory
- quantum dots
- molecular dynamics
- sensitive detection
- visible light
- high resolution
- reduced graphene oxide
- walled carbon nanotubes
- label free
- room temperature
- molecular dynamics simulations
- carbon nanotubes
- genome wide
- single cell
- gold nanoparticles
- dna methylation
- structural basis
- low cost
- living cells
- tissue engineering
- transition metal