Award Date

December 2023

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry and Biochemistry

First Committee Member

Clemens Heske

Second Committee Member

Balakrishnan Naduvalath

Third Committee Member

Dong-Chan Lee

Fourth Committee Member

Joshua Island

Number of Pages

94

Abstract

Molybdenum disulfide has a wide range of applications in energy conversion devices, like thin-film solar cells, batteries, bio sensors, and more. Although the properties of MoS2 and other transition metal dichalcogenides (TMDC) have been widely studied, disagreements and discrepancies regarding its electronic structure remain.

In this thesis, a highly-oriented synthetic 2H phase MoS2 single crystal is investigated using a toolchest of spectroscopic techniques to uncover its chemical and electronic properties. Lab-based x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), inverse photoemission spectroscopy (IPES), and low energy electron diffraction (LEED) were performed at UNLV and combined with resonant inelastic soft x-ray scattering (RIXS) at the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Together with theoretical calculations of the density of states and band structure, an in-depth picture of MoS2 properties is painted. In addition, the effects of mechanical exfoliation on the chemical and electronic environment of the MoS2 crystal surface is discussed. The results are compared to past studies and the established knowledge of the electronic structure of MoS2.

Keywords

Bandgaps; Chemical structure; Electronic structure; MoS2; Photoelectron spectroscopy; Single crystal

Disciplines

Condensed Matter Physics | Physical Chemistry

File Format

pdf

File Size

1530 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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