Dear Colleagues and Students,
You are cordially invited to UNAM Nanocolloquium seminars focusing on advancements in the field of nanoscience and nanotechnology. The seminars bring us the most recent developments in these exciting fields. This week’s talk will be presented by Dr. Ivan Verzhbitskiy and Prof. Goki Eda.
Title: “Light-Matter Interactions in 2D van der Waals Semiconductors and Their Heterostructures”
Date: March 08, 2019 (Friday)
Refreshments: 15:40
Time: 16:00
Place: UNAM Conference Hall
ABSTRACT:
Van der Waals semiconductors are crystalline compounds that naturally appear as a stack of loosely bound layers. When isolated, the individual layers are effectively two-dimensional, having thicknesses of no more than a few atoms. Such extreme dimensionality provides a unique opportunity to study many-body effects through optical spectroscopy. These ultimately thin quantum wells host excitons of extremely large binding energy and giant oscillator strength, thus playing a fundamental role in mediating the strong light-matter interactions. In this talk, I will discuss the mechanisms of strong excitonic absorption and band nesting effects [1], robustness and dimensionality of the excitons [2] and their decay dynamics in monolayer Transition Metal Dichalcogenides (TMDs) and their heterostructures [3]. Specifically, I will talk about the interactions of excitons with other quasi-particles through strong dipole-dipole coupling [4]. After which, I will focus on our recent progress in realization of electrical generation, manipulation and detection of excitons and their complexes in van der Waals materials [5]. I will shed more light on tunable excitonic electroluminescence from high-quality monolayer TMDs and how 2D insulating barrier of few-layer boron nitride can be used to engineer the unipolar hot carrier injection.
About the Speakers:
Dr. Ivan Verzhbitskiy received his B.Sc. and M.Sc. degrees in physics from Saint Petersburg State University, Russia, and completed his Ph.D. in Prof. M. Chrysos’s group at the University of Angers, France, in 2011. He worked with Dr. C. Casiraghi as a post‐doctoral associate at Free University, Berlin, where he studied electronic and optical properties of graphene, carbon nanotubes, and graphene nanoribbons. He joined Prof. Eda’s research group in National University of Singapore as a Research Fellow in 2013. His research interests rest mainly in the study of optical, optoelectronic, and charge transport mechanisms in low‐dimensional materials.
Dr. Eda received his M.Sc. in Materials Science and Engineering from Worcester Polytechnic Institute in 2006 and Ph.D. in the same discipline from Rutgers University in 2009. He became a Newton International Fellow of the Royal Society of the UK and worked at Imperial College London. Dr. Eda joined the National University of Singapore as an Assistant Professor of Physics and Chemistry, and a member of the Centre for Advanced 2D Materials in 2011. He is a recipient of the Singapore National Research Foundation (NRF) Research Fellowship and many awards including the Singapore National Academy of Science (SNAS) Young Scientist Award, University Young Researcher Award, and IPS Omicron Nanotechnology Award. He is an Associate Editor of npj 2D Materials and Applications.
* Ecole Polytechnique Fédérale de Lausanne