Cambridge Supervisor: Sir Richard Friend
Berkeley Host: Graham Fleming
Johanna Hall is a 3rd year Physical Chemistry PhD candidate in Graham Fleming’s group at the University of California, Berkeley. She obtained a B.S. in Environmental Engineering with minors in Biology and Global Development from the Georgia Institute of Technology in 2022. In her research, she uses a combination of experimental and computational techniques to study the energy transfer networks in photosynthetic light harvesting systems. Findings from this research could be used to improve solar energy technologies.
In Cambridge, Johanna plans to work with Sir Richard Friend to research novel semiconductors for applications in photovoltaics. Professor Friend’s research group has identified a class of molecules containing tris(2,4,6-trichlorophenyl)methyl (TTM) radicals, which have the ability to create an intermolecular charge transfer state following photoexcitation when phenyl groups are attached (P3TTM). The unpaired electron in this charge-transferred state can be mobile, but questions remain regarding the capacity of this charge transfer to occur over long distance and generate an electrical current. Answering these questions will be the focus of Johanna’s research exchange. If long-range charge transfer and electrical current can be detected in materials comprising only P3TTM molecules, this would be a significant finding in OPVs research and demonstrate the capacity of these organic molecules to be used in solar energy harvesting devices.