Topic: Scanning Probe Methods for Photovoltaics
Reporter: Dr. David Ginger（University of Washington）
Time: 13:30-14:40, 14/14/2018(Friday)
Place:Room 529, building 18, Ming palace campus

Organizers: Department of international cooperation, State key laboratory of mechanics and control of mechanical structures, College of Aerospace Engineering.

Summary of report:
 A range of emerging materials, from perovskite solar cells, to polymer batteries, and even bioelectronic transistors, show strong variations in performance associated with the nanoscale structure of the active material.  In this talk, I will discuss our work using a combination of multimodal in situ probes to unravel the often complex interplay of electronic, ionic, and even ferroelectric, behaviors that connect processing, structure, and function in these materials, with an emphasis in probing dynamic processes on timescales ranging from the sub-microsecond to hundreds of seconds.  We study the dynamics of ion motion in soft polymer films as a function of temperature, doping level, and polymer composition, and make quantitative comparisons between local time-resolved electrostatic force microscopy (trEFM) and bulk dynamics measured via electrochemical impedance in these systems.  Finally, we show how these methods can also probe both fast (microsecond) scale ion dynamics at grain boundaries in halide perovskite thin films, as well slow (hundreds of seconds) ion migration and defect formation in perovskite semiconductor devices.

Speaker Profile:

David S. Ginger earned dual B.S. degrees in chemistry and physics at Indiana University in 1997 with departmental honors and highest distinction, performing undergraduate research with Victor E. Viola. He received a British Marshall Scholarship and an NSF Graduate Fellowship and completed his Ph.D. in physics with Neil C. Greenham in the Optoelectronics group at the University of Cambridge (UK) in 2001. After a joint NIH and DuPont Postdoctoral Fellowship at Northwestern University in Chad Mirkin's lab, he joined the faculty at the University of Washington in Seattle where he is currently the Alvin L. and Verla R. Kwiram Endowed Professor in Chemistry, Washington Research Foundation Distinguished Scholar in Clean Energy, and Adjunct Professor of Physics, and serves as the Associate Director of the Washington state funded UW Clean Energy Institute. He is an elected fellow of the AAAS (American Association for the Advancement of Science) and has been named a Research Corporation Cottrell Scholar, a Research Corporation Scialog Fellow in solar energy conversion, an Alfred P. Sloan Foundation Research Fellow, a Camille Dreyfus Teacher-Scholar, and has received the Presidential Early Career Award for Scientists and Engineers, and the ACS Unilever Award in Colloid and Surfactant Science. He is the 2012 recipient of the Burton Medal of the Microscopy Society of America, and participated in the 2012-2013 class of the Defense Science Study Group. His research centers on the physical chemistry of nanostructured materials with applications in optoelectronics, energy and sensing, and his group makes use of techniques ranging from scanning probe microscopy to optical spectroscopy. He is also an Associate Editor at the ACS journal Chemical Reviews.