The field of 2D materials, based on ultrathin sheets that otherwise form layered materials was started and dominated for a long time by graphene. While graphene can be described by a lot of superlatives, just like everything else in life, it can also have limitations when it comes to certain applications. One example is the absence of a band gap which is an important drawback for applications that require semiconductors, for example in electronics where a band gap is needed to make a transistor switch that can be turned off or for solar cells that efficiently converts light into electricity. Graphite is not the only layered material though, so the realisation that experimental approaches originally developed for graphene can be extended to other layered materials such as transition metal dichalcogenides (TMDCs) with semiconducting molybdenum disulphide (MoS2) as one of the best known examples, has fuelled the rapid growth of interest in 2D materials beyond graphene. We now know of over 500 such materials to choose from, all with interesting properties. Examples include NbSe2 which is a superconductor, VS2 predicted to be a ferromagnet or CrSiTe3 predicted to be a semiconducting ferromagnet.
People very often ask me “which 2D material is best?” Our civilisations are based on using a multitude of materials and the choice of the best material is determined by its application. It is time to adopt a similar approach in nanoscience and stop expecting that one single wonder material can solve all our problems. Given the history of the 2D materials field, some materials such as TMDCs are better explored with some key applications emerging such as in valleytronics, while others such as PdSe2 have yet to be explored. Yet they all have something new to offer; we only have to try hard enough to find what it is. As the Editor-in-chief of npj 2D materials and applications I will strive to keep a balance and select the best papers on “more established” and “new” 2D materials, being reported on for the first time. This new journal is part of the nature research portfolio and of the nature partner journal series. Open access and online only, I hope that it will serve the 2D materials’ community by widely disseminating the most exciting and impactful new findings and stimulating discussion and further research.
Prof. Andras Kis
Laboratory of Nanoscale Electronics and Structures,
EPFL, Lausanne, Switzerland