Structurally driven one-dimensional electron confinement in sub-5-nm graphene nanowrinkles.
Graphene-based carbon materials such as fullerenes, carbon nanotubes, and graphenes have distinct and unique electronic properties that depend on their dimensionality and geometric structures. Graphene wrinkles with pseudo one-dimensional structures have been observed in a graphene sheet. However, their one-dimensional electronic properties have never been observed because of their large widths. Here we report the unique electronic structure of graphene nanowrinkles in a graphene sheet grown on Ni(111), the width of which was small enough to cause one-dimensional electron confinement. Use of spatially resolved, scanning tunnelling spectroscopy revealed bandgap opening and a one-dimensional van Hove singularity in the graphene nanowrinkles, as well as the chemical potential distribution across the graphene nanowrinkles. This observation allows us to realize a metallic-semiconducting-metallic junction in a single graphene sheet. Our demonstration of one-dimensional electron confinement in graphene provides the novel possibility of controlling its electronic properties not by chemical modification but by 'mechanical structuring'.
Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Center for Multidimensional Carbon Materials, Institute of Basic Science, UNIST-gil 50, Ulsan 689-798, Korea.|Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
Hyunseob
H
Lim
Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Department of Chemistry, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 680-749, Korea.
Jaehoon
J
Jung
Center for Multidimensional Carbon Materials, Institute of Basic Science, UNIST-gil 50, Ulsan 689-798, Korea.|Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
Rodney S
RS
Ruoff
Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Yousoo
Y
Kim