Colloquia & Guest Speakers

Heteroepitaxy in 2D: Challenges and New Approaches

Dr. Joan Marie Redwing, The Pennsylvania State University

Monday, April 16, 2018
3:30 p.m.

Goergen 101

joan marie redwing


The spectrum of two-dimensional (2D) materials “beyond graphene” has been continually expanding driven by the compelling properties of layered chalcogenide materials in monolayer and few-layer form. These materials include 2D transition metal dichalcogenide (TMD) monolayer films that are only a few atoms thick, topological insulator bismuth chalcogenide films that only conduct on the 2D surface, and multilayers of dissimilar chalcogenide films whose properties are dominated by 2D interfaces. The full realization of the scientific and technological potential of these new 2D materials will require developing atomic-level mastery over the wafer scale synthesis of samples with high crystalline quality and low defect densities.

Our research is aimed at the development of an epitaxial growth technology for layered chalcogenides, similar to that which exists for III-V and other compound semiconductors, based on gas source chemical vapor deposition (CVD).  Our studies thus far have focused primarily on transition metal dichalcogenides including WSe2, MoS2and WS2and are aimed at understanding fundamentals of nucleation, epitaxy and anisotropic growth that are characteristic of van der Waals crystals. This work is part of the 2D Crystal Consortium (2DCC) at Penn State. The 2DCC is an  NSF-supported Materials Innovation Platform facility focused on advancing the science and practice of 2D materials synthesis for next generation electronics.  Information on the 2DCC facility, in-house research and user program will also be provided.


Joan M. Redwing received her Ph.D. in Chemical Engineering from the University of Wisconsin-Madison. After working as research engineer at Advanced Technology Materials Inc., she joined the faculty of the Department of Materials Science and Engineering at Penn State University in 1999. She holds an adjunct appointment in the Department of Electrical Engineering as serves as director of the 2D Crystal Consortium – Materials Innovation Platform. Her research focuses on understanding fundamental mechanisms of crystal growth and epitaxy of electronic materials, with a particular emphasis on thin film and nanomaterial synthesis by chemical vapor deposition. Dr. Redwing currently serves as vice president of the American Association for Crystal Growth and is an associate editor for the Journal of Crystal Growth. She is a fellow of the Materials Research Society, the American Physical Society and the American Association for the Advancement of Science and is a senior member of IEEE.  She is an author or co-author on over 270 publications in refereed journals with over 11,000 citations and holds 8 U.S. patents.

Location:  Goergen 101

Refreshments will be served.