FIP Seminar: Mechanisms of Optical Nonuniformities in 2DM-Heterostructures for Multi-Dimensional Sensing Applications

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Wed, 02/07/2024 - 12:00 to 13:00

Dr. Ignatova

Presenter

Dr. Tetyana Ignatova, Assistant Professor, Nanoscience, Joint School of Nanoscience and Nanoengineering, UNC-G and NC A&T

Lattice mismatch and work function modulation in vertical two-dimensional materials heterostructures (2DM-Heterostructures) result in strain and charge transfer, often varying at a nanometer scale, that influence device performance. Herein a multidimensional optical imaging technique is developed in order to map subdiffractional distributions for doping and strain and understand the role of those for modulation of the electronic properties of the material. Vertical heterostructures comprised of monolayer graphene and single-layer flakes of transition metal dichalcogenide MoS2 were fabricated and examined for biosensing response. We found that non-uniform broadening of components of multimodal signal correlates with the statistical distribution of local optical properties of the heterostructure. Multidimensional nanoscale imaging allows one to reveal the physical origin for such a local response. 

Acknowledgements: DOD [Contract #W911QY2220006], NSF DMR-1539916 (2DCC-MIP), NSF MRSEC DMR-2011839, NSF ECCS-1542174 (SENIC: NNCI) 

Tetyana Ignatova is an Associate Professor of Nanoscience in the Joint School of Nanoscience and Nanoengineering at the University of North Carolina at Greensboro. She received her M.S. degree in Radiophysics and Electronics from the Kharkiv State University in Ukraine, and her Ph.D. in Physics from Lehigh University. After three years as a postdoctoral associate at University of California Irvine and Lehigh University, she joined the UNCG faculty in 2017. Her research interests are in the area of understanding and engineering optical and electronic properties of novel low dimensional materials.