The discovery of monolayer graphene has led to a Nobel Prize in Physics in 2010. This has stimulated research on a wide variety of two-dimensional (2D) layered materials. The coupling of metallic graphene, semiconducting 2D transition metal dichalcogenides (TMDCs) and black phosphorus has attracted tremendous amount of interest in new electronic and optoelectronic applications. Together with other 2D materials such as the wide band gap boron nitride nanosheets (BNNSs), all these 2D materials have led towards an emerging field of van der Waal 2D heterostructures. This book is originally published in Electronics (MDPI) as a special issue of “Two-Dimensional Electronics and Optoelectronics”.

The book consists of a total of eight papers, including two review articles, covering important topics of 2D materials. These papers represent some of the important topics on 2D materials and devices. Promises and challenges of 2D materials are discussed herein, which provide a great recent guidance for future research and development.