LAUSR

The isolation of graphene in 2004 from graphite was a defining moment for the “birth” of the field of two-dimensional (2D) materials. In recent years, a rapidly increasing number of papers have been published focusing on nongraphene layered materials, including transition-metal dichalcogenides (TMDs), because of the new properties and applications that emerge upon 2D confinement. For example, these 2D materials show a transition from an indirect band gap in multilayers to a direct band gap inmonolayers, which opens up many possibilities in optoelectronics and electronics. In addition, the manipulation of valley degrees of freedom was demonstrated by optical pumping through valley selective circularly polarized light, thus exploiting the valley as an information carrier. Furthermore, the lack of inversion symmetry in monolayer MoS2 and other TMDs materials leads to a very strong spin–orbit coupling, a condition necessary for realizing spintronic devices. These remarkable features promise a whole new field of rich physics in electron transport of 2DTMDs such as coupling of spin and valley physics, valleytronics, and quantum spin Hall effect-based devices. Because of the rapid development of 2D materials in recent years, we have gladly taken the opportunity to publish this Special Issue focusing on “Beyond graphene – The booming development of novel 2D nanomaterials”. Our aim is to highlight the remarkable contributions made by leading scientists in this important research area and the broad impacts of 2D materials. In this Special Issue, many experts in the relevant fields discuss the different kinds of 2D materials, such as molybdenum disulfide, molybdenum carbide, and so on, to produce high quality devices including field effect transistors, photodetectors, sensors, and memory. Although it is not possible to include all the topics in this quickly developing field, we hope this collection of papers can provide readers with an overview of the recent progress Weida Hu received his Ph.D. degree with honors in microelectronics and solid-state electronics from the Shanghai Institute of Technology Physics (SITP), Chinese Academy of Sciences (CAS), in 2007. Then he joined State Key Laboratory for Infrared Physics of SITP, CAS. He is currently a full professor on fabrication and characterization of infrared thin-film and low-dimensional photodetectors in SITP, CAS. He has authored or coauthored more than 100 technical journal papers and conference presentations.