Electronic Theses and Dissertations

Identifier

4773

Yan Jiang

Date

2016

Document Type

Thesis

Degree Name

Master of Science

Major

Physics

Concentration

Materials Science

Committee Chair

Jingbiao Cui

Committee Member

Sanjay R Mishra

Committee Member

Xiao Shen

Committee Member

Firouzeh Sabri

Abstract

Two-dimensional single and few layers of molybdenum disulfide have attracted much attention due to their unique property and potential for applications. Synthesis of large area MoS2 on a substrate will lead to possible device fabrication. In this study, large area MoS2 of high crystallinity and large size were synthesized by a Chemical Vapor Deposition process. Both triangle-shape-flakes and continuous films of monolayer and multilayer MoS2 were obtained. Analysis of layer roughness, size, thickness, uniformity and crystallinity were studied by optical microscope, atomic force microscope, scanning electron microscope, and Raman microscope. The effects of precursor concentration, pressure in deposition chamber, gas flow rate and plasma treatment on MoS2 layer growth were also investigated in order to understand the growth mechanism of triangle-shape MoS2 on SiO2/Si substrate. Understanding of the initial growth was also achieved by studying the crucial role played by the substrate surface condition in MoS2 growth. It was found that the right surface condition before deposition is necessary for successful growth of single and few layer MoS2. The study of growth process will eventually help deposit ultra large size MoS2 layers of wafer scale for applications.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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