Electronic transport through suspended graphene nanoribbons using a scanning tunneling microscope

Abstract

In this thesis, I investigated the two-terminal electronic transport through individualspin-hosting graphene nanoribbons (GNRs) suspended between the tip and the substrate of a low-temperature scanning tunneling microscope. Three types of GNRs were investigated: a seven and a five-seven-five armchair graphene nanoribbon, both with substitutional boron doping and a hybrid structure of (3,1)-chiral graphene nanoribbons and iron porphyrin. The ribbons were fabricated in situ under ultra-high vacuum conditions using on-surface synthesis strategies and characterized by means of scanning tunneling microscopy and spectroscopy (STM and STS). Bond resolved low bias images using a CO-functionalized tip confirmed the atomic structure of the molecules. Selected ribbons were positioned in a free-standing configuration bridging STM tip and substrate by mechanical manipulation with the STM tip.