Electronic Theses and Dissertations

Identifier

6598

Date

2020

Document Type

Thesis

Degree Name

Master of Science

Major

Physics

Concentration

Computational Physics

Committee Chair

Xiao Shen

Committee Member

Thang Ba Hoang

Committee Member

Chenhui Peng

Abstract

The memristor is viewed as a promising material to store digital information and has analog applications that drew researchers’ attention. Researchers explored the possibilities of using memristors to simulate synapses in the human brain. WO3 is one of the materials that can make memristors. Based on the mechanism of memristors, we know the motion of defects in WO3 changes the Schottky barrier and the current; thus, it can make the switch between high resistance state, HRS, and low resistance state, LRS. This paper will explore vacancy diffusivity in WO3. In this research, we concentrate on the cubic and monoclinic structure of WO3. We use the first principle density functional theory or DFT, and hybrid DFT to calculate the formation energy of different charge states of oxygen vacancies in WO3 and plot the graph of Fermi level to find the charge state with the lowest formation energy conditions. We use the nudged elastic band method to get the energy barrier for the vacancies to migrate inside the structure.

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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