Biography
Biography: Yousoo Kim
Abstract
One of the unique properties of the sp2-carbon allotropes, such as fullerenes, carbon nanotubes and graphenes, is that their electronic structures differ significantly among them according to characteristic electron confinement based on their dimensionality and geometric structures, which can be influenced not only by charge injection and chemical bonding but also structural modification. In this talk, I will discuss the electronic structures of various sp2-carbon allotropes on metal substrates investigated by scanning tunneling microscopy and spectroscopy. In particular, it is focused on the one dimensional (1D) electronic structure in a graphene nano wrinkle (GNW) of an epitaxially grown graphene (EG) sheet on Ni(111), the width of which was small enough (less than 5 nm) to cause 1D electron confinement. Use of spatially resolved, scanning tunneling spectroscopy revealed band-gap opening and a 1D van Hove singularity in the GNW, as well as the chemical potential distribution across the GNW. Our demonstration of 1D electron confinement in an EG is the novel possibility of controlling its electronic properties not by chemical modification but by mechanical structuring in a controlled manner.