title: Nanometre-thick single-crystalline nanosheets grown at the water-air interface.
abstract: To date, the preparation of free-standing 2D nanomaterials has been largely limited to the exfoliation of van der Waals solids. The lack of a robust mechanism for the bottom-up synthesis of 2D nanomaterials from non-layered materials has become an obstacle to further explore the physical properties and advanced applications of 2D nanomaterials. Here we demonstrate that surfactant monolayers can serve as soft templates guiding the nucleation and growth of 2D nanomaterials in large area beyond the limitation of van der Waals solids. One- to 2-nm-thick, single-crystalline free-standing ZnO nanosheets with sizes up to tens of micrometres are synthesized at the water-air interface. In this process, the packing density of surfactant monolayers adapts to the sub-phase metal ions and guides the epitaxial growth of nanosheets. It is thus named adaptive ionic layer epitaxy (AILE). The electronic properties of ZnO nanosheets and AILE of other materials are also investigated.
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Jung-Hun
authors.identifier: http://orcid.org/0000-0002-5039-2503
authors.initials: JH
authors.lastname: Seo
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Guangfu
authors.initials: G
authors.lastname: Luo
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Starr
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Zhaodong
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Dalong
authors.initials: D
authors.lastname: Geng
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Yin
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Shaoyang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Fraser
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Dane
authors.identifier: http://orcid.org/0000-0002-4911-0046
authors.initials: D
authors.lastname: Morgan
authors.affiliation: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Zhenqiang
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Xudong
authors.initials: X
authors.lastname: Wang