Ursel Bangert is Bernal Chair in Microscopy and Imaging at the University of Limerick, following positions of Reader and Lecturer at the Universities of Manchester and Surrey, and a career of more than 30 years in the area of electron microscopy. She has been heavily involved in the conception and managerial activities of Electron Microscopy Facilities at Liverpool (NorthWest STEM; Co-I) and at Daresbury (SuperSTEM; Co-I), and has been overseeing the Manchester University School of Materials Electron Optical facilities. She is currently building up an International Centre for Ultra-High Resolution Imaging and Characterisation at the University of Limerick, where she obtained funding for a world-class Titan Themis double corrected, monochromated, analytical transmission electron microscope with in-situ measurement capabilities.
Ursel Bangert's research activities concentrate on investigations of microstructure and growth phenomena and related plasmonic and opto-electronic properties of materials, especially semiconducting and low-dimensional nano-materials, having lead to sustained research output (180+ papers including Nature papers, Review Articles, Perspectives, and 50+ refereed conference papers, not including the 60 or so un-refereed conference papers). She has contributed prolifically at national and international conferences, delivered numerous invited talks and seminars (details can be found on Scopus). She has pioneered low loss electron energy loss (EEL) spectroscopy for highly spatially resolved electronic structure studies in wide bandgap semiconductors and diamond as well as single atom spectroscopy of carbon nanotubes. Since its discovery she has worked on Graphene (and other 2-Ds discovered shortly thereafter), carrying out electron microscopy in the Manchester Graphene Group (A. Geim, Nobel Prize 2010), and was first to conduct atomic resolution HAADF imaging and morphology studies via electron diffraction, as well as electron energy loss spectroscopy on this material.
Her intention and vision has been and is to use top-of-the-range Electron Microscopy instrumentation to see and understand materials on the atomic scale, i.e., to further the topic of highly spatially resolved (single atom) imaging in combination with atomic scale spectroscopy so as to access/assess the electronic and optical properties of materials, in particular of nano-materials (novel 2-, 1- and 0-dimensional materials), and to furthermore combine this with in-situ techniques, so as to directly follow the atomic-scale behaviour of such materials. e.g., under electrical bias or in chemical-atmosphere conditions. All this will serve fundamental research, and exploration of practical use of these nanostructures in photo-emission, sunlight harvesting and photovoltaics, with the aim of designing prototype devices.
Ursel Bangert's current research is focussed on fundamental investigations of the local dependence of opto-electronic properties and tailoring thereof, in 1D semiconductor assemblies, carbon nanotubes, graphene and other novel 2-D materials, e.g., transition metal dichalcogenides and MXene, aiming at practical use in photo-emission, optical enhancers, wave guides, photovoltaics, quantum metrology and at design of prototype devices.
She has pioneered work in ultrahigh resolution high angle dark field imaging of graphene (first to show atomic-scale impurity and defect behaviour, e.g., metal-atom mediated graphene etching and healing), in tailoring plasmon characteristics of graphene, and in single atom spectroscopy (first to demonstrate spectroscopic fingerprinting' of controllably introduced foreign atoms in nano-carbons, i.e., revealing simultaneously chemical bonding configuration and lattice position of a single impurity atom. This was achieved by new developments in sub-Ǻ imaging and analytical electron microscopy (EELS) at the Daresbury SuperSTEM. Furthermore, electron energy loss spectroscopy at ultra low loss energies (valence band EELS) provided first evidence of the impact of microstructural defects on the local electronic bandstructure when combined with theoretical backup (ab initio calculations) through collaboration with theoretical groups (e.g., at Exeter and Leeds University).
Application-oriented research objectives concern tailoring and tuning of the opto-electronic properties of novel 2-D versions of dichalcogenides (including materials with negative plasmon dispersion for direct light coupling) and of MAX phases (MXenes ->unknown territory) through controlled physical and chemical functionalisation via ion beam modification. The same approach is taken with carbon nanotubes for applications in optical enhancers, wave guides, photonic and light harvesting devices as well as for integration into semiconductor electronics. Ion beam modification has also been applied for doping silica/Si-nanoscrystal systems with rare-earth elements to achieve light emission and thereby develop silicon photonics technologies.
Past research has included establishing the role of defects in the ageing and failure mechanisms of semiconductor devices. Further to the academic aspect, the investigations were aimed at trouble shooting in real devices in order to cut market losses of, e.g., semiconductor lasers. This entailed exploring electron microscopies/ spectroscopies with ultra high spatial resolution and to apply these to materials of wide and medium bandgaps enabling spatially resolved chemical and electronic structure studies, via EELS, of self-organized growth phenomena in strained III-V semiconductor hetero systems and SiGe. Thus a universal roughening transition curve (temperature versus strain) and strain driven compositional segregation in semiconductor quantum wells, wires and dots could be established. Furthermore, bandgap states at extended defects in wide band gap semiconductors, diamond and perovskites and surface plasmon phenomena in nanocarbons, semiconductor and metal nanospheres could be revealed.
A persisting goal is to improve the energy resolution in electron spectroscopy and to combine electron microscopy with simultaneous optical excitation and detection, which will enable in-situ assessment of a material's electronic bandstructure on the nanoscopic scale