Structure-property relationship of 2D material modifications

The recent years have seen an explosive growth in the variety of new low-dimensional materials with fascinating properties and a diverse application potential. For this proposal, two-dimensional materials are at the focus of interest, in particular graphene but also other two-dimensional materials such as molybdenum disulfide, niobium diselenide, hexagonal boron nitride, mono-layer bismuth strontium calcium copper oxide (BSCCO), and related systems. In the ideal case, many of these materials are expected to have very unique electronic, mechanical, chemical and thermal properties. However, modifications such as doping, amorphization, functionalization, or combinations (heterostructures) of 2-D materials will be needed to tailor and fine-tune their properties, defince active areas, structure or join them into electronic circuits, or in some cases may simply be inevitable as a result of synthesis and processing. Moreover, new 2-D structures that have no 3-D counterpart might be derived by a modification of existing 2-D materials.
This project aims to make significant advances in understanding the structure-property relationships and control of material modifications at the atomic level. For this purpose, we will join several atomic-resolution local probes which in their combination will allow us to determine structural, electronic, optical and mechanical properties at the level of individual defects, functional groups, dopants or adsorbates. We will explore the use of atom-sized electron beams for local modifications e.g. to create vacancies, incorporate dopants, or to introduce structural defects in predefined patterns. On the same structures we will employ electron energy loss spectroscopy, the analysis of charge redistribution from direct images, as well as scanning tunneling microscopy and spectroscopy in a novel doubleprobe configuration in order to assess their electronic, optical or mechanical properties at the same, atomic level, resolution. Overall, this project will bring significant advances in the understanding of these materials, in the control over properties by structural modifications, and new routes to their application.