Exploring the Effect of Geometric and Interfacial Variations on Two-Dimensional Materials by Computational Methods

Abstract

Two-dimensional (2D) materials exhibit distinct differences from bulk materials due to quantum mechanical effects derived from their thinness. Since various parameters drive totally different characteristics of 2D materials, careful considerations are required in practical applications. Despite extensive interest in 2D materials, there are a number of unanswered questions regarding the underlying physics. The aim of this dissertation is to investigate the factors influencing the intrinsic properties of 2D materials and to boost their potential applications through comprehensive insights. Especially, this dissertation focuses on how their geometric structures and interfacial interaction affect the electronic properties and chemical reactions through density functional theory calculations. Chapter 1 reviews the background, general characteristics, and synthesis methods of 2D materials, including the contribution of computational simulation in the field of 2D materials. Chapter 2 provides a methodological background on density functional theory. Chapter 3 investigates the origin of van Hove singularity in graphene nanowrinkle grown on metal substrate. Chapter 4 reveals the correlation between synthesis condition and crystallinity of grown 2D molybdenum disulfide films. Chapter 5 introduces a new approach to overcoming the endothermic conversion of 2D diamond-like boron nitride structures and examines their properties. These findings contribute to a deeper understanding of how structural engineering and interfacial interaction can influence electronic properties and chemical reaction, suggesting potential new directions in nanotechnology. In addition, the collaboration between computational analysis and experimental observation has proven to be an effective approach for elucidating the properties of 2D materials, thereby contributing to the advancement of further applications.