Aleksandra Radenovic: Nanoscopy of 2D materials

Jean Comtet, Evgenii Glushkov, Vytautas Navikas, Jiandong Feng and Aleksandra Radenovic Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, 1015 Lausanne, Switzerland In this talk, I will detail our strategy on how to translate nanoscopy techniques into the field of materials science. We have developed and applied different modalities of nanoscopy techniques that provide unique insights about the type and density of defects together with the spectral characterization at locations determined with nanometre-scale precision. We focus on defects hosted in two classes of 2D materials: hexagonal boron nitride (h-BN) and transition metal dichalcogenides (TMDs), such as MoS2, WS2, MoSe2, WSe2, and MoTe2. Defects hosted in 2D materials such as h-BN and TMDs are particularly interesting due to their single photon emission. SP emitters are stable concerning transfer onto other substrates, opening the possibility of integrating them into more complex nanophotonic devices and paving the way for future semiconductor quantum information processing technologies.  Transmission electron microscopy and scanning probe microscopy can provide atomic resolution. However, both techniques require strict sample preparation protocols and are not optimal for fast in-situ operation or applications requiring the characterization of large areas. In contrast, Nanoscopy can operate in –situ under ambient conditions and is compatible with the probing of defect chemistry and dynamics in different pH environments and under different solvents. We also demonstrated the high-content characterization of 2D materials using silicon nitride waveguides as imaging platforms that allow integration of more complex nanophotonic circuits. Aleksandra Radenovic received her master's degree in physics from the University of Zagreb in 1999 before joining Professor Giovanni Dietler's Laboratory of Physics of Living Matter in 2000 at University of Lausanne. There she earned her Doctor of Sciences degree in 2003. In 2003 she was also awarded a research scholarship for young researchers from the Swiss Foundation for Scientific Research which allowed her to spend 3 years as a postdoctoral fellow at the University of California, Berkeley (2004-2007). Before joining EPFL as Assistant Professor in 2008 she spent 6 months at NIH and Janelia Farm. In 2010 she received the ERC starting grant and in 2015 SNSF Consolidator grant. Her group is interested in using novel nanomaterials and single molecule experimental techniques to study fundamental questions at nanoscale.