Joan M. Redwing received her B.S. in Chemical Engineering from the University of Pittsburgh and her Ph.D. in Chemical Engineering from the University of Wisconsin-Madison. After receiving her Ph.D., she was employed as a research engineer at Advanced Technology Materials, Inc. where she worked on the development of group III-nitride materials and devices. Dr. Redwing joined the faculty of the Department of Materials Science and Engineering at Penn State University in 2000. She holds an adjunct appointment in the Department of Electrical Engineering and is a member of the Materials Research Institute. She currently serves as Director of the 2D Crystal Consortium (2DCC), an NSF-funded Materials Innovation Platform national user facility. Dr. Redwing’s research interests are in the general area of electronic materials synthesis and characterization with a specific emphasis on semiconductor thin film, nanowire and 2D materials synthesis by metalorganic chemical vapor deposition. She currently serves as vice president of the American Association for Crystal Growth, is an associate editor for the Journal of Crystal Growth and is the North American regional editor for the journal 2D materials. She is a fellow of APS, MRS and AAAS and was a Fulbright Scholar to Sweden in 2016. She is a co-author on over 300 publications in refereed journals and holds 8 U.S. patents.
This faculty member is associated with the Penn State Intercollege Graduate Degree Program (IGDP) in Materials Science and Engineering (MatSE) where a multitude of perspectives and cross-disciplinary collaboration within research is highly valued. Graduate students in the IGDP in MatSE may work with faculty members from across Penn State.
Dr. Redwing’s research interests lie in the general area of electronic and optoelectronic materials synthesis and characterization with a special emphasis on metalorganic chemical vapor deposition (MOCVD) processing of semiconductor thin films and nanomaterials.
An area of current focus is the synthesis of 2D materials, specifically layered chalcogenides such as the transition metal dichalcogenides (TMDs), MX2, where M=Mo, W, Nb, etc. and X=S, Se, Te. Semiconducting TMD monolayers, which are only a few atoms thick, offer compelling properties including direct bandgap in the visible range, good carrier mobility at the ultra-thin limit, and coupled spin-valley polarization. There is growing interest in 2D TMDs for applications in nanoelectronics and 3D integration with silicon, low power biomimetic devices and photonics. Current research projects in the group are aimed at understanding fundamental mechanisms of van der Waals epitaxy of layered chalcogenides and the development of wafer-scale epitaxial growth technologies for TMD monolayers and heterostructures. This work is carried out in the NSF-supported 2D Crystal Consortium (2DCC) Materials Innovation Platform facility at Penn State on custom-designed MOCVD tools that incorporate in situ monitoring during growth and ambient controlled characterization of samples post-growth.
The development of wide bandgap group III-nitride (AlGaInN) thin films and device structures by MOCVD is an area of continuing research. Group III-nitrides are widely used in light emitting diodes for solid state lighting and in power transistors and switching devices for communications and electric vehicles. Areas of current interest include epitaxial growth and doping of ultra-wide bandgap nitrides (AlN, AlGaN), synthesis of 2D nitrides including hBN and 2D GaNx and patterned growth of nanowire arrays for vacuum nanoelectronics. This work is carried out using a custom-designed MOCVD system capable of growth at temperatures up to 1500oC that includes a multibeam optical stress (MOS) sensor system for in-situ measurements of film stress due to heteroepitaxy and doping.