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

Use of this thesis is restricted to the UNT Community. Off-campus users must log in to read.

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 ... continued below

Creation Information

Wu, Min May 2016.

Context

This thesis is part of the collection entitled: UNT Theses and Dissertations and was provided by UNT Libraries to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 423 times , with 8 in the last month . More information about this thesis can be viewed below.

Who

People and organizations associated with either the creation of this thesis or its content.

Author

Chair

Committee Members

Publisher

Rights Holder

For guidance see Citations, Rights, Re-Use.

  • Wu, Min

Provided By

UNT Libraries

The UNT Libraries serve the university and community by providing access to physical and online collections, fostering information literacy, supporting academic research, and much, much more.

Contact Us

What

Descriptive information to help identify this thesis. Follow the links below to find similar items on the Digital Library.

Degree Information

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.

Language

Identifier

Unique identifying numbers for this thesis in the Digital Library or other systems.

Collections

This thesis is part of the following collection of related materials.

UNT Theses and Dissertations

Theses and dissertations represent a wealth of scholarly and artistic content created by masters and doctoral students in the degree-seeking process. Some ETDs in this collection are restricted to use by the UNT community.

What responsibilities do I have when using this thesis?

When

Dates and time periods associated with this thesis.

Creation Date

  • May 2016

Added to The UNT Digital Library

  • June 28, 2016, 4:28 p.m.

Description Last Updated

  • July 25, 2016, 1:19 p.m.

Usage Statistics

When was this thesis last used?

Yesterday: 0
Past 30 days: 8
Total Uses: 423

Interact With This Thesis

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Wu, Min. Adhesion and Surface Energy Profiles of Large-area Atomic Layers of Two-dimensional MoS2 on Rigid Substrates by Facile Methods, thesis, May 2016; Denton, Texas. (digital.library.unt.edu/ark:/67531/metadc849762/: accessed December 15, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .