Embedded pseudo graphene nanoribbons oriented via Ge(110) surface reconstruction

Abstract

Graphene nanoribbon, which is the one-dimensional form of graphene, is an attractive nano structure for next generation electronic devices. Herein, we studied the electronic properties of pseudo-GNRs in large-scale graphene sheets grown on Ge(110) using low temperature scanning tunneling microscopy (STM) and spectroscopy (STS). Based on our STM results, the pseudo-GNRs are aligned in the <112> direction of the Ge surface; the alignment of the pseudo-GNRs is controlled by the surface reconstruction of Ge(110) substrate, which can be an important merit in terms of the mass fabrication. Bandgap energies ranging from ∼0.12 to ∼0.3 eV were measured via STS on pseudo-GNRs in graphene/Ge(110), while the surrounding graphene area outside the pseudo-GNR growth region shows the typical electronic structure of graphene, verifying the spontaneous formation of metallic-semiconducting-metallic junction nanostructure. This study unveils the geometric and electronic properties of pseudo-GNRs in graphene/Ge(110), providing essential information for the realization of next-generation nanoelectronic devices. • Pseudo-GNRs aligned in the <112> direction on Ge surface. • Alignment controlled by surface reconstruction of Ge substrate. • Bandgap energies from ∼0.12 to ∼0.3 eV measured via STS on pseudo-GNRS. • Graphene outside growth regions showed typical electronic structure of graphene.