Two-dimensional semiconducting transition metal dichalcogenides (TMDs), which can be easily exfoliated into thin layers, have attracted attention because of their interesting electrical and optical properties. The band structure of TMDs change dramatically with the number of layers, going from an indirect gap in bulk materials to direct gap in monolayers. Sizable band gap makes TMDs a promising material for optical and electronic applications. Indirect to direct transition of band gaps in 2D-TMDs lead to a drastic increase in photoluminescence (PL) intensity as the number of layers decrease. However, intrinsic defects and strain within the structure of monolayer TMD crystals can affect their electronic and optical properties.

Since the great success of graphene, atomically thin-layered nanomaterials, called two dimensional (2D) materials, have attracted tremendous attention due to their extraordinary physical properties. Specifically, van der Waals heterostructured architectures based on a few 2D materials, named atomic-scale Lego, have been proposed as unprecedented platforms for the implementation of versatile devices with a completely novel function or extremely high-performance, shifting the research paradigm in materials science and engineering. Thus, diverse 2D materials beyond existing bulk materials have been widely studied for promising electronic, optoelectronic, mechanical, and thermoelectric applications. Especially, this Special Issue included the recent advances in the unique preparation methods such as exfoliation-based synthesis and vacuum-based deposition of diverse 2D materials and also their device applications based on interesting physical properties. Specifically, this Editorial consists of the following two parts: Preparation methods of 2D materials and Properties of 2D materials

Defects in Two-Dimensional Materials addresses the fundamental physics and chemistry of defects in 2D materials and their effects on physical, electrical and optical properties. The book explores 2D materials such as graphene, hexagonal boron nitride (h-BN) and transition metal dichalcogenides (TMD). This knowledge will enable scientists and engineers to tune 2D materials properties to meet specific application requirements. The book reviews the techniques to characterize 2D material defects and compares the defects present in the various 2D materials (e.g. graphene, h-BN, TMDs, phosphorene, silicene, etc.). As two-dimensional materials research and development is a fast-growing field that could lead to many industrial applications, the primary objective of this book is to review, discuss and present opportunities in controlling defects in these materials to improve device performance in general or use the defects in a controlled way for novel applications. Presents the theory, physics and chemistry of 2D materials Catalogues defects of 2D materials and their impacts on materials properties and performance Reviews methods to characterize, control and engineer defects in 2D materials

This book is a printed edition of the Special Issue "Integration of 2D Materials for Electronics Applications" that was published in Crystals

Presenting recent progress in anisotropic 2D materials research, reader is introduced to phosphorene and its arsenic alloys, monochalcogenides of group IV elements in the form of MX (M = Ge, Sn and X = S, Se, Te), low-symmetry transition-metal dichalcogenide (TMD) materials such as rhenium disulphide (ReS2) and rhenium diselenide (ReSe2), and organic 2D materials. Providing detailed synthesis protocols and characterization techniques for these various anisotropic 2D materials, readers will learn their specific technological scopes for next generation electronics, optoelectronics and biomedical applications, challenges and future directions. Edited by an leading expert, contributors cover enhanced many-body interactions and high binding energy 1D particle dynamics to showcase design of high-performance optoelectronic devices; anisotropic polariton for designing polariton based laser systems; applications in bio-imaging, cancer diagnosis and therapies, drug delivery and release, and antibacterial performance; and finally, their potential in nano-electro-mechanical devices. Considering all these areas in detail, this book is a useful reference to the scientific communities working in related research fields, especially for materials scientists, chemists, physicists and electronics/electrical/energy engineers. This book may also be of use to those in chemical academia and industry more broadly.

This thesis introduces a unique approach of applying atomic force microscopy to study the nanoelectromechanical properties of 2D materials, providing high-resolution computer-generated imagery (CGI) and diagrams to aid readers’ understanding and visualization. The isolation of graphene and, shortly after, a host of other 2D materials has attracted a great deal of interest in the scientific community for both their range of extremely desirable and their record-breaking properties. Amongst these properties are some of the highest elastic moduli and tensile strengths ever observed in nature. The work, which was undertaken at Lancaster University’s Physics department in conjunction with the University of Manchester and the National Physical Laboratory, offers a new approach to understanding the nanomechanical and nanoelectromechanical properties of 2D materials by utilising the nanoscale and nanosecond resolution of ultrasonic force and heterodyne force microscopy (UFM and HFM) – both contact mode atomic force microscopy (AFM) techniques. Using this approach and developing several other new techniques the authors succeeded in probing samples’ subsurface and mechanical properties, which would otherwise remain hidden. Lastly, by using a new technique, coined electrostatic heterodyne force microscopy (E-HFM), the authors were able to observe nanoscale electromechanical vibrations with a nanometre and nanosecond resolution, in addition to probing the local electrostatic environment of devices fabricated from 2D materials.

Major developments in the semiconductor industry are on the horizon through the use of two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides, for integrated circuits (ICs). 2D Materials for Nanoelectronics is the first comprehensive treatment of these materials and their applications in nanoelectronic devices.Compris