Bernal Institute Research Forum

Date: 31st July 2018 to 31st July 2018
Time: 13:00 to 14:00
Duration: One hour
Location: MSG-025 MSSI Building Extension

PRESENTATION BY
Professor Alexei Gruverman, Department of Physics and Astronomy, University of Nebraska-Lincoln, USA.

PRESENTATION TITLE
Polarization-enabled Electronic Properties of Hybrid 2D-ferroelectric Structures.

ABSTRACT
In recent years, there has been an unprecedented interest in various two-dimensional (2D) materials that often possess unique physical and chemical properties that cannot be found in their three-dimensional counterparts. An important advantage of 2D materials is the fact that due to their planar morphology they can be easily integrated with other 2D materials and functional films, resulting in multilayered structures with new properties. In particular, there was a considerable interest in a novel type of electronic devices, in which graphene, a 2D carbon material, was coupled with different ferroelectric (FE) materials. Electrically switchable ferroelectric polarization opens a possibility of electrical control of the functional properties of the adjacent graphene layer.

In this presentation, the implementation of the hybrid electronic devices comprising 2D materials and FE thin films (2D-FE) that exhibit polarization-controlled non-volatile modulation of the electronic transport will be discussed. While many 2D materials can be considered in conjunction with FE materials, this talk primarily focuses on the use of graphene and transition metal dichalcogenide MoS2. Specifically, it will be shown how polarization reversal can modulate (1) the in-plane transport of the interfacial conducting channel in the FE field effect devices, and (2) the perpendicular-to-plane tunneling conductance in the FE tunnel junction devices. It will be demonstrated that interface engineering is a critical component determining the functional properties of these devices. A simple phenomenological modeling is developed to predict how the interface chemistry affects the electronic and transport properties of the 2D-FE structures.

ABOUT THE PRESENTER
Professor Alexei Gruverman currently holds the position of Charles Bessey Professor at University of Nebraska-Lincoln within the Department of Physics and Astronomy. He received his PhD in solid state physics from the Ural State University in Russia. After graduation, he worked as a postdoctoral researcher at the Joint Research Center for Atom Technology (JRCAT), Japan, where he initiated a project on scanning probe microscopy studies of ferroelectrics. He then joined Sony Corporation to work on the problems related to characterization and reliability of ferroelectric memory devices by PSM. In 2000, he joined the faculty at North Carolina State University. He has published over 200 articles in refereed journals and several book chapters.

Tea/coffee will be available at 12h45.

For further information, please contact: michele.conroy@ul.ie, ursel.bangert@ul.ie