Novel Synthesis of 2-Dimensional Group III and IV Metals and Binary Compounds
Open Access
- Author:
- Briggs, Natalie
- Graduate Program:
- Materials Science and Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- April 20, 2020
- Committee Members:
- Joshua Alexander Robinson, Dissertation Advisor/Co-Advisor
Joshua Alexander Robinson, Committee Chair/Co-Chair
Joan Marie Redwing, Committee Member
Susan B Sinnott, Committee Member
Mauricio Terrones, Outside Member
Thomas Mallouk, Special Member
Susan B Sinnott, Program Head/Chair - Keywords:
- 2D materials
Silicon carbide
Intercalation
Epitaxial graphene
2D metals
Confinement heteroepitaxy
2D nitrides - Abstract:
- Atomically-thin, or 2-dimensional (2D) materials have sparked tremendous interest in a range of scientific communities due to fundamental research afforded by single or few-atom-thick materials, as well as the potential for impact and application in electronic, optical, sensing, and quantum technologies. While prototypical 2D materials such as graphene and molybdenum disulfide may be mechanically exfoliated or deposited single layers at a time, current strategies to stabilize materials in 2D form apply primarily to van der Waals, or naturally layered materials. 2D materials “beyond van der Waals” – or 2D allotropes of non-layered, 3D materials – have the potential to expand the library of 2D material properties beyond those known today. The work presented in this dissertation demonstrates intercalation of epitaxial graphene/silicon carbide and an approach termed Confinement Heteroepitaxy (CHet) as a means of synthesizing non-layered materials in 2D form. Specifically, this dissertation presents studies regarding the realization of 2D forms of group-III and group-IV metals (Ga, In, Sn), nitrides (GaNx, InNx), and oxides (GaOx), drawing inspiration from initial reports of 2D gallium nitride and studies of epitaxial graphene/SiC doping. Chapter 1 provides an introduction to 2D materials and the synthetic approaches investigated through this dissertation research and Chapter 2 details the experimental methods implemented. Findings on 2D metals and the CHet process are presented in Chapter 3. Chapter 3 also presents findings on properties unique to 2D CHet materials, such as superconductivity and nonlinear optical properties. Reaction of intercalated, 2D metals to form 2D Ga- and In-nitride compounds is discussed in Chapter 4, and reaction to form 2D Ga-oxide is discussed in Chapter 5. These 2D compound materials are of interest both for potential implementation in high-power technologies, as well as for nucleation or seed layers for thin film nitride and oxide growth. The promise of ultra-thin, 2D material-based nucleation layers for enhanced nitride growth is demonstrated in Chapter 6, which presents studies of ultra-thin GaN seed layers created through ammonia annealing of 2D gallium selenide. Ongoing investigations are discussed in Chapter 7, along with suggestions for further research and discussion of areas which require further investigation. Funding for this dissertation work was provided by the Semiconductor Research Corporation/Intel Global Research Collaboration Fellowship Program task 2741.001, Northrop Grumman Mission Systems’ University Research Program, and the 2-Dimensional Crystal Consortium National Science Foundation (NSF) Materials Innovation Platform under cooperative agreement DMR-1539916. The findings and conclusions in this dissertation do not necessarily reflect the views of the funding agencies.