title: Electric-Field-Assisted Directed Assembly of Transition Metal Dichalcogenide Monolayer Sheets.
abstract: Directed assembly of two-dimensional (2D) layered materials, such as transition metal dichalcogenides, holds great promise for large-scale electronic and optoelectronic applications. Here, we demonstrate controlled placement of solution-suspended monolayer tungsten disulfide (WS2) sheets on a substrate using electric-field-assisted assembly. Micrometer-sized triangular WS2 monolayers are selectively positioned on a lithographically defined interdigitated guiding electrode structure using the dielectrophoretic force induced on the sheets in a nonuniform field. Triangular sheets with sizes comparable to the interelectrode gap assemble with an observed preferential orientation where one side of the triangle spans across the electrode gap. This orientation of the sheets relative to the guiding electrode is confirmed to be the lowest energy configuration using semianalytical calculations. Nearly all sheets assemble without observable physical deformation, and postassembly photoluminescence and Raman spectroscopy characterization of the monolayers reveal that they retain their as-grown crystalline quality. These results show that the field-assisted assembly process may be used for large-area bottom-up integration of 2D monolayer materials for nanodevice applications.
authors.forename: Donna D
authors.initials: DD
authors.lastname: Deng
authors.forename: Zhong
authors.initials: Z
authors.lastname: Lin
authors.forename: Ana Laura
authors.initials: AL
authors.lastname: Elías
authors.forename: Nestor
authors.initials: N
authors.lastname: Perea-Lopez
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Chanjing
authors.initials: C
authors.lastname: Zhou
authors.forename: Kehao
authors.initials: K
authors.lastname: Zhang
authors.forename: Simin
authors.initials: S
authors.lastname: Feng
authors.affiliation: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
authors.forename: Humberto
authors.initials: H
authors.lastname: Terrones
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Mayer
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Robinson
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terrones
authors.affiliation: Department of Electrical and Computer Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Theresa S
authors.initials: TS
authors.lastname: Mayer
keywords: chemical vapor deposition; dielectrophoretic assembly; transition metal dichalcogenide; tungsten disulfide