Synthesis and Characterization of Two-Dimensional Transition Metal Dichalcogenides, Alloys, and Heterojunctions Over Various Substrates via Chemical Vapor Deposition
Year: 2017
Type: dissertation
Abstract: Interest in two-dimensional (2D) electronic materials has exploded in the past decade, starting with the isolation of single layer graphene in 2004 by Novoselov.1, 2 Similar to graphene, as a stable material in the single-layer, transition metal dichalcogenides (TMDs) further the advancement of 2D materials, but also provide an intrinsic transition to a direct bandgap in the single layer,3, 4 thus giving these materials an advantage over graphene. Furthermore, TMDs have some of the highest notable Ion/Ioff ratios of other 2D materials, making them extremely favorable.5, 6 However, none of these 2D materials can be used as a standalone for modern electronic applications, therefore, heterostructures of these materials must be created.7-11 An understanding of the way these materials are synthesized and ways to manipulate the synthesis is necessary to achieve such structures. Chemical vapor deposition (CVD) is a commonly used method to create single-layer TMDs12-18 among others such as mechanical exfoliation19, 20 and metal sulfurization/selenization.21, 22 Here I present facile methods by which to synthesize pristine, pure, 2D TMDs via CVD process manipulation.19 Additionally, in-situ operation of the CVD furnaces leads to the ability to alloy these materials and create heterostructures, leading to a study of tunable optical and physical properties.12, 22, 23 Last, I show the use of various/nanofabricated features on growth substrates in order to lead to a deeper understanding of the growth mechanisms for TMDs.14, 24-26
Author: David Barroso
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Semiconductor Research Corporation, Defense Advanced Research Projects Agency, Materials Research Science and Engineering Center, Harvard University, Materials Research Science and Engineering Center, University of Nebraska, Division of Materials Research
Awards: MRSEC: Polarization and Spin Phenomena in Nanoferroic Structures (P-SPINS), G1318668994, G1334192132, G1482239811, G1663779495, G222768804, G3190346089, CONTROLLING STRUCTURAL, ELECTRONIC, AND ENERGY FLOW DYNAMICS OF CATALYTIC PROCESSES THROUGH TAILORED NANOSTRUCTURES, G351742188, G413815026, G4612195255, G4779665080, MRI: Acquisition of an X-ray Photoelectron Spectrometer for Research and Education, G5941807339, G6161270434, G6258602847, CONTROLLING STRUCTURAL ELECTRONIC AND ENERGY FLOW DYNAMICS OF CATALYTIC PROCESSES THROUGH TAILORED N, EAGER: Lateral Heterojunctions: Fabrication & Characteristics of a Novel Concept in 2D Materials Electronics, G7002107284, THEORETICAL AND COMPUTATIONAL STUDIES OF CHARACTERISTICS OF METALLIC NANOSTRUCTURES, G8250619254, THEORETICAL AND COMPUTATIONAL STUDIES OF CHARACTERISTICS OF METALLIC NANOALLOYS
OpenAlex ID: W2797578403