title: van der Waals Solids from Self-Assembled Nanoscale Building Blocks.
abstract: Traditional atomic van der Waals materials such as graphene, hexagonal boron-nitride, and transition metal dichalcogenides have received widespread attention due to the wealth of unusual physical and chemical behaviors that arise when charges, spins, and vibrations are confined to a plane. Though not as widespread as their atomic counterparts, molecule-based two-dimensional (2D) layered solids offer significant benefits; their structural flexibility will enable the development of materials with tunable properties. Here we describe a layered van der Waals solid self-assembled from a structure-directing building block and C60 fullerene. The resulting crystalline solid contains a corrugated monolayer of neutral fullerenes and can be mechanically exfoliated. The absorption spectrum of the bulk solid shows an optical gap of 390 ± 40 meV that is consistent with thermal activation energy obtained from electrical transport measurement. We find that the dimensional confinement of fullerenes significantly modulates the optical and electronic properties compared to the bulk solid.
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Bonnie
authors.initials: B
authors.lastname: Choi
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Jaeeun
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Paley
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: M Tuan
authors.initials: MT
authors.lastname: Trinh
authors.affiliation: Department of Chemistry, Barnard College , New York, New York 10027, United States.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Paley
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Karch
authors.affiliation: Department of Chemistry, Barnard College , New York, New York 10027, United States.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Crowther
authors.affiliation: KU-KIST Graduate School of Converging Science and Technology, Korea University , Seoul 136-701, Korea.
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Rutgers University-Newark , Newark, New Jersey 07102, United States.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Lalancette
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Physics, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Philip
authors.initials: P
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Steigerwald
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Colin
authors.initials: C
authors.lastname: Nuckolls
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Xavier
authors.initials: X
authors.lastname: Roy
keywords: Self-assembly; fullerene; molecular clusters; two-dimensional materials