Precursor Geometry Determines the Growth Mechanism in Graphene Nanoribbons

Fabian Schulz, Peter H. Jacobse, Filippo Federici Canova, Joost van der Lit, David Z. Gao, Adrianus van den Hoogenband, Patrick Han, Robertus J. M. Klein Gebbink, Marc-Etienne Moret, Pekka M. Joensuu, Ingmar Swart, Peter Liljeroth

Research output: Contribution to journalArticleScientificpeer-review

58 Citations (Scopus)

Abstract

On-surface synthesis with molecular precursors has emerged as the de facto route to atomically well-defined graphene nanoribbons (GNRs) with controlled zigzag and armchair edges. On Au(111) and Ag(111) surfaces, the prototypical precursor 10,10'-dibromo-9,9'-bianthryl (DBBA) polymerizes through an Ullmann reaction to form straight GNRs with armchair edges. However, on Cu(111), irrespective of the bianthryl precursor (dibromo-, dichloro-, or halogen-free bianthryl), the Ullmann route is inactive, and instead, identical chiral GNRs are formed. Using atomically resolved noncontact atomic force microscopy (nc-AFM), we studied the growth mechanism in detail. In contrast to the nonplanar BA-derived precursors, planar dibromoperylene (DBP) molecules do form armchair GNRs by Ullmann coupling on Cu(111), as they do on Au(111). These results highlight the role of the substrate, precursor shape, and molecule-molecule interactions as decisive factors in determining the reaction pathway. Our findings establish a new design paradigm for molecular precursors and opens a route to the realization of previously unattainable covalently bonded nanostructures.

Original languageEnglish
Pages (from-to)2896-2904
Number of pages9
JournalJournal of Physical Chemistry C
Volume121
Issue number5
DOIs
Publication statusPublished - 9 Feb 2017
MoE publication typeA1 Journal article-refereed

Keywords

  • BOTTOM-UP FABRICATION
  • REVEALS CHIRAL EDGES
  • ON-SURFACE SYNTHESIS
  • ATOMIC-FORCE MICROSCOPY
  • BAND-GAP
  • ENANTIOSELECTIVITY
  • NANOGRAPHENE
  • MOLECULES
  • STRATEGY
  • FILMS

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