(in cooperation with PTB Braunschweig and DFG Research Unit FOR5242)
2D materials such as graphene, "beyond graphene" (transition metal chalcogenides, hBN, gallenene, silicene, phosphene, etc.) and in particular materials that are difficult to realize as two-dimensional layers by traditional technologies (such as graphene-like zinc oxide (g-ZnO ), GaN etc.) is one of the most important research areas in materials science and engineering. Unique properties of such materials and especially of their heterostacks have the potential to significantly improve electronic components and technologies. New manufacturing approaches lead to a new route for two-dimensional crystal growth and could also lead to the production of self-organized stacks of 2D materials as novel property-on-demand heterostructures and thus to a breakthrough in future devices and nanotechnologies.
Highlight is selforganized fabrication of gallenene in confinement - inbetween graphene and SiC wafer - via intercalation of graphene under room temperature and atmospheric pressure:
New cost-effective manufacturing and processing methods (in cooperation with PTB Braunschweig)
The key issue that will define the successful implementation of 2D materials in mass production is development of their cost-effective large area deposition and processing technologies. Some of the areas of our research on this topic are solid-melt exfoliation, solid-melt intercalation-exfoliation, sublimation sandwich approach, van der Waals epitaxy, SAMs conversion, pen-litho.
Elemental 2D-Materials and their Derivatives (in cooperation with PTB Braunschweig and PTB Berlin)
Among 2D materials “beyond graphene” elemental atomic layers of the materials group III to group VI (group 13 to group 16), so called Xenes (silicene, phosphorene, stanene etc.) are gaining rapidly growing attention. Existence of B, Al, Ga, In, C (beyond graphene), Si, Ge, Sn, Pb, P, As, Sb, Bi, Se, Te as 2D materials is either experimentally proved or theoretically predicted. Behavior of these Xenes covers the spectrum from metal to semiconducting properties providing wide range of potential applications in the areas of photonics, electronics, energy conversion. Among these materials silicene and phosphorene are studied during several years and comparatively well known. At present fabrication approaches as well as properties investigations of gallenene are at the initial stages of research. It is already proposed that gallenene would be of special interest for energy conversion applications. Recently it was shown by several groups, that hydrogenated gallenene, called gallenane, is promising material as 2D flexible and stable metal for nanotechnological applications and, moreover, it is extremely promising candidate for room temperature spintronics. Also other derivatives of gallenene obtained by its transformation to oxides, nitrides etc. are of great interest. Further applications fields will be clear after the properties of gallenene and related derivatives will be studied in detail. Our research was initially focused on gallenene+derivatives and now it involves further listed above elements.
Large scale (limited by the wafer dimensions) selbstorganized formation of gallenene sheet under graphene through Liquid Metal Intercalation Technique (Li.M.I.T.) at ambient conditions: