2D Electronic Chalcogenide Nanomaterials
Two-dimensional (2D) transition metal dichalcogenides have gained renewed interest due to their interesting electrical properties such as layer-dependent bandgap engineering, valley degrees of freedom, topological states, and 2D superconductivity. Our ability to thin them down to a single layer and their anisotropic bonding nature opens up possibilities for novel heterostructures where we can tailor their electronic properties. For practical applications, it is critical to synthesize thin films of these materials in a controlled fashion. I will present our synthesis efforts to create large-area thin films and heterostructures based on the 2D chalcogenides, and report their electronic transport properties. I will discuss how the transport properties change at the nanoscale and due to the microstructure of the films, and explore possible energy applications, in particular thermoelectrics and electrocatalysis involving hydrogen evolution reaction. Particular materials that I will focus on are the predicted Wely semimetal WTe2 that has recently shown extremely large magnetoresistance and SnTe, a topological crystalline insulator.
Judy J. Cha is the Carol & Douglas Melamed assistant professor in the Department of Mechanical Engineering and Materials Science at Yale University. Prior to Yale, she was a post-doctoral researcher at Stanford University in the department of Materials Science and Engineering. She received her Ph.D. in Applied Physics from Cornell University, Ithaca, NY in 2009. Notable awards she has received include the Yale Arthur Greer Memorial Prize (2016), the IBM Faculty Award (2014), the Presidential Student Award from Microscopy Society of America (2010), and the Graduate Student Silver Award at the Spring Materials Research Society meeting (2008).
Her research focuses on synthesis and transport measurements of two-dimensional chalcogenide nanostructures, in particular topological insulator and topological crystalline insulator nanoribbons and nanoplates. She uses analytical scanning transmission electron microscopy and electron energy-loss spectroscopy to characterize the synthesized nanomaterials in order to correlate the transport properties to their local atomic structures.
Molecular Engineering and Sciences Seminar Series
This weekly seminar brings together students, faculty and invited guests from various disciplines across campus to explore current trends in molecular engineering and nanotechnology. It is a forum for active interdisciplinary discussions. These talks are open to the public and attract a diverse audience of students and faculty.