Recovery of edge states of graphene nanoislands on an iridium substrate by silicon intercalation
graphene nanoisland, zigzag edge, edge state, scanning tunneling microscopy, density functional theory
ABSTRACT Finite-sized graphene sheets, such as graphene nanoislands (GNIs), are promising candidates for practical applications in graphene-based nanoelectronics. GNIs with well-defined zigzag edges are predicted to have spin-polarized edge-states similar to those of zigzag-edged graphene nanoribbons, which can achieve graphene spintronics. However, it has been reported that GNIs on metal substrates have no edge states because of interactions with the substrate. We used a combination of scanning tunneling microscopy, spectroscopy, and density functional theory calculations to demonstrate that the edge states of GNIs on an Ir substrate can be recovered by intercalating a layer of Si atoms between the GNIs and the substrate. We also found that the edge states gradually shift to the Fermi level with increasing island size. This work provides a method to investigate spin-polarized edge states in high-quality graphene nanostructures on a metal substrate.
Tsinghua University Press
Hui Chen,Yande Que,Lei Tao,Yu-Yang Zhang,Xiao Lin,Wende Xiao,Dongfei Wang,Shixuan Du,Sokrates T. Pantelides,Hong-Jun Gao, Recovery of edge states of graphene nanoislands on an iridium substrate by silicon intercalation. NanoRes.2018, 11(7): 3722–3729