DTU's researchers have contributed to the discovery of a brand-new class of 2D materials that are able to bind single atoms between their ultra-thin layers. It opens up a whole new dimension in working with materials design.
A collaboration between DTU's 2D materials research team and the Centre for Advanced 2D Materials at the National University of Singapore (NUS) has made it possible to produce a brand-new group of 2D materials.
A 2D material is a material that consists of a single or only a very fewer layers of atoms, and thus represents the very thinnest material imaginable.
What is completely new in this case is that the researchers have succeeded in implanting atoms between two or more layers of stacked 2D materials. They have even been able to control exactly how many atoms to implant, and in so doing have been able to make a 2D material with implanted metal atoms magnetic to varying degrees.
"We have had a bit of fun in naming the new class of materials 2.5D, as it lies somewhere between the traditional 2D and 3D materials. An implanted layer of atoms in the 2D materials thus opens up completely new possibilities for designing materials with extraordinary properties which we haven't been able to do until now," says Anders Christian Riis-Jensen from DTU Physics, who is responsible for the calculations behind the new discovery.
World leader in quantum mechanical calculations
Over the past ten years, DTU Physics has specialized in carrying out large quantum mechanical calculations of the properties of the many thousands of 2D materials which are currently known. It has placed the research team among the leading groups of its kind worldwide.
"In connection with discovering the new class of 2D materials, we've screened about 100 different 2D materials to identify which were most suitable as stable hosts for injecting single atoms," says Anders Christian Riis-Jensen.
The calculations served as the starting point for the work of the experimental group at the National University of Singapore, who are able to produce 2D materials in their laboratory. Here, the researchers designed 30-40 different 2D materials with injected atoms. The vast majority were materials which DTU's calculations showed as being be stable and suitable for attaching atoms to.
New materials design continues
The outstanding findings have just been published in the prestigious scientific journal Nature. The article describes how the calculations and the experiments with implanting atoms have been carried out for some of the most well-known 2D materials, namely the so-called TMDs (Transition Metal Dichalcogenides). Using these readily available materials also allows research groups all over the world to build on the research.
"At DTU, we will also continue to explore this new dimension which has been opened up by being able to attach a single atom between the layers of 2D materials. The cooperation with the National University of Singapore will hopefully also be continued, as our competences complement each other well," says Professor Kristian Thygesen, who heads the DTU research group.
Due to the size and properties of the 2D materials, interest is already being shown in using them, for example in ultracompact electronics and optical components. This interest that will only increase if it becomes possible in future to control the magnetic and electronic properties of the materials by stacking them and implanting atoms between the layers.
