Boron-doped graphene nanoribbons: Electronic structure and Raman fingerprint

DOI: 10.1021/acsnano.8b04125

Authors: Boris V. Senkovskiy (Universitat zu Koln) , Dmitry Yu. Usachov (Universitat zu Koln) , Alexander V. Fedorov (Universitat zu Koln; St. Petersburg State University; IFW Dresden) , Tomas Marangoni (University of California at Berkeley) , Danny Haberer (University of California at Berkeley) , Cesare Tresca (University of L'Aquila; Sorbonne Universites-UPMC univ Paris 6; CNRS-UMR) , Gianni Profeta (University of L'Aquila) , Vasile Caciuc (Peter Grunberg Institut (PGI-1); Institute for Advanced Simulation (IAS-1)) , Shigeru Tsukamoto (Peter Grunberg Institut (PGI-1); Institute for Advanced Simulation (IAS-1)) , Nicolae Atodiresei (Peter Grunberg Institut (PGI-1); Institute for Advanced Simulation (IAS-1)) , Niels Ehlen (Universitat zu Koln) , Chaoyu Chen (Synchrotron SOLEIL; Universite Paris-Saclay) , José Avila (Synchrotron SOLEIL; Universite Paris-Saclay) , Maria C. Asensio (Synchrotron SOLEIL; Universite Paris-Saclay) , Andrei Yu. Varykhalov (Helmholtz-Zentrum Berlin fur Materialien und Energie) , Alexei Nefedov (Institut fur Funktionelle Grenz) , Christof Wöll (Institut fur Funktionelle Grenz) , Timur K. Kim (Diamond Light Source) , Moritz Hoesch (Diamond Light Source; Deutsches Elektronen-Synchrotron) , Felix R. Fischer (University of California at Berkeley; Lawrence Berkeley National Laboratory) , Alexander Gruneis (Universitat zu Koln)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Nano

State: Published (Approved)
Published: July 2018
Diamond Proposal Number(s): 17064

Abstract: 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 (ARPES), 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 to pristine 7AGNRs. We probe the phonons of B-7AGNRs by ultra-high vacuum (UHV) Raman spectroscopy and reveal the existence of characteristic splittings and red-shifts of 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 a 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 easy identification of B-7AGNRs, that is particularly useful for device fabrication.

Journal Keywords: graphene nanoribbons; boron doping; electronic structure; ARPES; Raman; substrate interaction

Diamond Keywords: Semiconductors

Subject Areas: Materials, Physics, Chemistry


Instruments: I05-ARPES

Other Facilities: Soleil; HZB BESSY II

Added On: 16/07/2018 10:04

Discipline Tags:

Molecular Physics Physics Physical Chemistry Hard condensed matter - structures Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)