More than Graphene.

Abstract

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 non-graphene 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 achieved in this exciting area, the potential broader impact of studies in 2D materials, and inspire many more to enter this field. As guest editors, we would like to thank all the authors for their efforts in submitting a wide variety of high-quality peer-reviewed articles. We are also grateful to the editorial and production staff of Small for their superb assistance. Finally, we hope that this timely themed Special Issue will provide a valuable reference and perspective for the research community working in this exciting field. We thank the National Natural Science Foundation of China (NSFC) for the support received for this themed issue. Peng Zhou received his bachelor and Ph.D. degree in physics from Fudan University in 2000 and 2005, respectively. He is currently a full professor on novel electronic devices and process in school of microelectronics, Fudan University. He has authored or co-authored more than 90 journal papers and conference presentations. 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. Lei Liao is currently a professor in the School of Physics and Electronics, Hunan University. His research focused on the high performance transistors based on low dimensional materials. He has published nearly 80 scientific papers such as Nature, PNAS, Nano Lett., etc., and holds several patents.