Ursel Bangert
Insights into 1D and 2D nano-materials: atomic-scale landscapes, single atom action and collective electron motion revealed by electron microscopy and spectroscopy.
Recent advancements in electron microscopy have made it possible to directly visualise sites of individual atoms in materials as well as reveal their chemical nature and local bandstructure. Using new generation aberration corrected (scanning) transmission electron microscopes, we combine atomic resolution imaging with electron energy loss spectroscopy and DFT modelling to uncover atomic-scale topography, morphology and constellations of defects, lattice impurities and ad atoms in nano-carbons (carbon nano-tubes and graphene). I will touch upon issues that will be particularly vital for nano-carbon device development and application, such as the interaction with metals, in the case of graphene (metal mediated graphene etching resulting in hole ‘drilling and filling’) and lattice doping via ion implantation in both, graphene and carbon nano-tubes. I will furthermore demonstrate collective charge carrier behaviour (plasmons) in these nano-structures as well as peculiarities and tailoring of such plasmons (enhancement), which has consequences for use as light emitters and harvesters. I will also present recent results of atomic-scale structure and composition of graphene derivatives and other 2-D materials (BN and transition metal dichalcogenides).