Adhesion and Surface Energy Profiles of Large-area Atomic Layers of Two-dimensional MoS2 on Rigid Substrates by Facile Methods Metadata

Title

• Main Title Adhesion and Surface Energy Profiles of Large-area Atomic Layers of Two-dimensional MoS2 on Rigid Substrates by Facile Methods

Creator

• Author: Wu, Min
  Creator Type: Personal

Contributor

• Chair: Choi, Wonbong, 1963-
  Contributor Type: Personal
  Contributor Info: Major Professor
• Committee Member: Choi, Tae-Youl
  Contributor Type: Personal
• Committee Member: Shi, Sheldon
  Contributor Type: Personal

Publisher

• Name: University of North Texas
  Place of Publication: Denton, Texas
  Additional Info: www.unt.edu

Date

• Creation: 2016-05

Language

• English

Description

• Content Description: Two-dimensional (2D) transition metal dichalcogenides (TMDs) show great potential for the future electronics, optoelectronics and energy applications. But, the studies unveiling their interactions with the host substrates are sparse and limits their practical use for real device applications. We report the facile nano-scratch method to determine the adhesion energy of the wafer scale MoS2 atomic layers attached to the SiO2/Si and sapphire substrates. The practical adhesion energy of monolayer MoS2 on the SiO2/Si substrate is 7.78 J/m2. The practical adhesion energy was found to be an increasing function of the MoS2 thickness. Unlike SiO2/Si substrates, MoS2 films grown on the sapphire possess higher bonding energy, which is attributed to the defect-free growth and less number of grain boundaries, as well as less stress and strain stored at the interface owing to the similarity of Thermal Expansion Coefficient (TEC) between MoS2 films and sapphire substrate. Furthermore, we calculated the surface free energy of 2D MoS2 by the facile contact angle measurements and Neumann model fitting. A surface free energy ~85.3 mJ/m2 in few layers thick MoS2 manifests the hydrophilic nature of 2D MoS2. The high surface energy of MoS2 helps explain the good bonding strength at MoS2/substrate interface. This simple adhesion energy and surface energy measurement methodology could further apply to other TMDs for their widespread use.
• Physical Description: v, 60 pages : illustrations

Subject

• Keyword: two-dimensional materials
• Keyword: MoS2
• Keyword: adhesion energy
• Keyword: surface free energy
• Keyword: nano-scratch technique
• Library of Congress Subject Headings: Adhesion.
• Library of Congress Subject Headings: Molybdenum disulfide.
• Library of Congress Subject Headings: Surface energy.

Collection

• Name: UNT Theses and Dissertations
  Code: UNTETD

Institution

• Name: UNT Libraries
  Code: UNT

Rights

• Rights Access: public
• Rights Holder: Wu, Min
• Rights License: copyright
• Rights Statement: Copyright is held by the author, unless otherwise noted. All rights Reserved.

Resource Type

• Thesis or Dissertation

Format

• Text

Identifier

• Accession or Local Control No: submission_209
• Archival Resource Key: ark:/67531/metadc849762

Degree

• Degree Name: Master of Science
• Degree Level: Master's
• Academic Department: Department of Mechanical and Energy Engineering
• College: College of Engineering
• Degree Discipline: Mechanical and Energy Engineering
• Degree Publication Type: thesi
• Degree Grantor: University of North Texas

Note

• Embargo Note: Item would be restricted to campus view only for 5 years. Start date for restriction period is the first day of the month immediately following graduation month: June 1 (May graduation), September 1 (August graduation), or January 1 of following year (December graduation). Embargo expired on 2021-05-01.