Two-Dimensional Materials

This chapter contains a theoretical background on two-dimensional (2D) materials referred to as layered nanomaterials, which can be grown on a substrate or exfoliated and placed on a substrate as a single-layer or N-layers. Regarding semiconductor materials, metallic graphene, insulator boron nitride (hBN), and composite TMD (metal and chalcogen elements have relevant properties for the semiconductor industry. The general physical properties of TMDs are associated with their bandgaps, valence and conduction bands, and the possible heterojunctions due to the stacking of monolayers on semiconductor substrates. Most 2D materials have a common hexagonal symmetry and suitable properties for high-performance electronic devices, such as sensors, batteries, and supercapacitors. This implies that applications of 2D materials depend on their dimensional limitations in bulk, continuous atomic structure (commonly honeycomb planes), purity, and environment. Nevertheless, computer making, energy storage, and medicine, among others, appear to be the most relevant industries to use high-tech graphene-containing products. The main emphasis hereafter is based on the research trends on 2D materials exposed to an electric field (Ef) in energy-producing devices (EPD). A theoretical analysis using the Lennard-Jones potential energy is included for predicting the maximum binding force needed to separate or exfoliate 2D atomic planes from bulk sources.