Structure and properties of chemically prepared nanographene islands characterized by scanning tunneling microscopy

TL;DR

This study investigates the atomic structure and electronic properties of chemically synthesized nanographene islands on Pt (111) using scanning tunneling microscopy, revealing edge-specific localized states.

Contribution

It provides experimental evidence of localized edge states at zigzag edges in nanographene islands, advancing understanding of their electronic properties.

Findings

Zigzag edges are predominant in nanographene islands.

Enhanced apparent height at zigzag edges indicates localized edge states.

Edge states are spatially and energetically localized at the Fermi level.

Abstract

Single layer graphene islands with a typical diameter of several nanometers were grown on a Pt (111) substrate. Scanning tunneling microscopy (STM) analysis showed most of islands are hexagonally shaped and the zigzag-type edge predominates over the armchair-type edge. The apparent height at the atoms on the zigzag edge is enhanced with respect to the inside atoms for a small sample bias voltage, while such an enhancement was not observed at the atoms on the armchair edge. This result provides an experimental evidence of spatially (at the zigzag edge) and energetically (at the Fermi level) localized edge state in the nanographene islands, which were prepared chemically on Pt (111).