Caltech Young Investigators Lecture

Abstract

Well-controlled nanostructures and their interfaces with surrounding materials are at the core of our most advanced technologies, from superconducting qubits to emerging catalysts. In particular, 3D metal integration with 2D van der Waals materials (2D/3D interfacing) is routinely required for the fabrication of nanoscale devices. However, nanometer-scale spatial fluctuations in the local 2D/3D interface directly affect properties and limit widespread application.

In this seminar, I will reveal local structure-property relationships at the 2D/3D interface using a combination of in situ atomic resolution transmission electron microscopy (TEM) and correlated spectroscopies. First, I will show how novel 2D/3D interfaces grown in ultra-high vacuum lead to epitaxial heterostructures with ultra-low defect density interfaces. Then, I will discuss the key parameters of 2D/3D growth, including the role of temperature, defects, moiré, surface energy, and thermodynamic equilibrium shapes. Lastly, I will describe how the 2D/3D interface structure influences local electronic and excitonic properties. Such understanding of the structureproperty-performance relationship allows versatile design of 2D/3D heterostructures for next generation nanoscale devices.

Bio

Kate Reidy is currently a PhD candidate and MIT Energy Initiative Fellow in Materials Science & Engineering at MIT, working with Prof. Frances Ross. She received her B.Sc in Nanoscience, Physics, and Chemistry of Advanced Materials from Trinity College Dublin, Ireland. Her research takes a ‘bottom up' approach to nanoscale design, tailoring material properties by understanding and manipulating their atomic structure. She develops in situ transmission electron microscopy (TEM) methods which provide high spatial and temporal resolution to elucidate kinetic growth mechanisms, chemical composition, and response to stimuli at the atomic scale. Her work has been recognized by the MIT School of Engineering, Microscopy Society of America, and the MIT Lemelson-Vest Award for Student Innovation. Outside of lab, she acts as representative on the Departmental Committee of Graduate Studies at MIT, helping to re-design the graduate core curriculum, and on the board of MIT Women in Materials Science.

This lecture is part of the Young Investigators Lecture Series sponsored by the Caltech Division of Engineering & Applied Science.