Optimized substrates and measurement approaches for Raman spectroscopy of graphene nanoribbons

Abstract

The on-surface synthesis of graphene nanoribbons (GNRs) allows for the fabrication of atomically precise narrow GNRs. Despite their exceptional properties which can be tuned by ribbon width and edge structure, significant challenges remain for GNR processing and characterization. In this contribution, we use Raman spectroscopy to characterize different types of GNRs on their growth substrate and to track their quality upon substrate transfer. We present a Raman-optimized (RO) device substrate and an optimized mapping approach that allows for acquisition of high-resolution Raman spectra, achieving enhancement factors as high as 120 with respect to signals measured on standard SiO2/Si substrates. We show that this approach is well-suited to routinely monitor the geometry-dependent low-frequency modes of GNRs. In particular, we track the radial breathing-like mode (RBLM) and the shear-like mode (SLM) for 5-, 7- and 9-atom wide armchair GNRs (AGNRs) and compare their frequencies with first-principles calculations.

arXiv comment*contributed equally 190722 - corrected typos

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Cited by in corpus (8)

• Graphene nanoribbons for quantum electronics
• A Universal Length-Dependent Vibrational Mode in Graphene Nanoribbons
• Growth optimization and device integration of narrow-bandgap graphene nanoribbons
• Quantifying Alignment and Quality of Graphene Nanoribbons: A Polarized Raman Spectroscopy Approach
• Understanding the optical properties of doped and undoped 9-armchair graphene nanoribbons in dispersion
• The role of precursor coverage in the synthesis and substrate transfer of graphene nanoribbons
• Scalable Etch-Free Transfer of Low-Dimensional Materials from Metal Films to Diverse Substrates
• Electrical and Structural Response of Nine-Atom-Wide Armchair Graphene Nanoribbon Transistors to Gamma Irradiation