title: Adhesion Energy of MoS2Thin Films on Silicon-Based Substrates Determined via the Attributes of a Single MoS2Wrinkle.
abstract: Understanding the energetics of adhesion between two-dimensional nanomaterials and their supporting substrates is crucial for the design and fabrication of corrersponding structures with controlled interfacial effects that influence phononics, charge-carrier distribution, and electronic response. Here, we show a mechanical energy model that equates the adhesion energy of MoS2on rigid and flat substrates (SiO2and Si3N4) to the attributes of a single wrinkle in a MoS2flake. The amplitude of the observed wrinkles was normalized for thickness (A/t) to select the wrinkles valid for the model. The adhesion energy values of 0.170 ± 0.033 J m-2for MoS2on SiO2and 0.252 ± 0.041 J m-2for MoS2on Si3N4were determined. This mechanical energy model is consistent with the model based on the local equilibrium at the contact point in the Young's equation. We also propose a method to measure the plane-strain in wrinkled MoS2. The geometrical properties (symmetry and normalized dimensions) of wrinkles and substrate effects are also discussed.
authors.affiliation: Department of Chemical Engineering, University of Illinois at Chicago , 810 South Clinton Street, Chicago, Illinois 60607, United States.
authors.forename: Shikai
authors.initials: S
authors.lastname: Deng
authors.affiliation: Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University , Beijing 100084, China.
authors.forename: Enlai
authors.identifier: http://orcid.org/0000-0003-1960-0260
authors.initials: E
authors.lastname: Gao
authors.affiliation: Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University , Beijing 100084, China.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Chemical Engineering, University of Illinois at Chicago , 810 South Clinton Street, Chicago, Illinois 60607, United States.
authors.forename: Vikas
authors.identifier: http://orcid.org/0000-0002-1102-1996
authors.initials: V
authors.lastname: Berry
keywords: MoS2; adhesion energy; silicon dioxide; silicon nitride; strain; wrinkles