Role of Organic Molecules in Organic-Inorganic Solar Cell Perovskites

• Speaker: Prof. Lee, Seung-Hun(University of Virginia)
• Date: Wednesday July 24, 2019 11:00am
• Place: Jungho Seminar Room

The record solar cell efficiency based on hybrid organic-inorganic perovskites (HOIPs) has reached 22.7% which rivals that of conventional silicon solar cells. Combined with its inexpensive solution-based processing and all earth abundant compositions, HOIPs are among the most promising next generation solar cell materials. In this talk, I will present our recent studies, using elastic and inelastic neutron scattering and photoluminescence techniques, and density functional theory calculations, on two HOIPs, methylammonium lead iodide and formamidinium lead iodide, to shed lights on the microscopic mechanism of the photovoltaic properties of the HOIPs.

1. Role of Organic Molecules in Phonon Melting and Charge Screening in Hybrid Organic-Inorganic Perovskites, Depei Zhang, Maiko Kofu, Tianran Chen, Wei-Liang Chen, Alexander Z. Chen, Mina Yoon, Chinnambedu Murugesan Raghavan, Tzu-Pei Chen, Douglas L. Abernathy, Benjamin J. Foley, Craig M. Brown, Guangyong Xu, Leland W. Harriger, Ryoichi Kajimoto, Mitsutaka Nakamura, Seiko Ohira-Kawamura, Chun-Wei Chen, Yu-Ming Chang, Joshua J. Choi, and Seung-Hun Lee, submitted (2019).
2. Origin of Long Lifetime of Band-Edge Charge Carriers in Organic-Inorganic Lead Iodide Perovskites, Tianran Chen, Wei-Liang Chen, Benjamin J. Foley, Jooseop Lee, Jacob Ruff, J. Y. Peter Ko, Craig M. Brown, Leland W. Harriger, Depei Zhang, Changwon Park, Mina Yoon, Yu-Ming Chang, Joshua J. Choi, and Seung-Hun Lee, Proceedings of National Academy of Sciences 114, 7519-7524 (2017).
3. Entropy Driven Structural Transition and Kinetic Trapping in Formamidinium Lead Iodide Perovskite, Tianran Chen, Benjamin J. Foley, Changwon Park, Craig M. Brown, Leland W. Harriger, Jooseop Lee, Jacob Ruff, Mina Yoon, Joshua J. Choi, and Seung-Hun Lee, Science Advances 2, e1601650 (2016).
4. Rotational dynamics of organic cations in CH3NH3PbI3, T. Chen, B. J. Foley, B. Ipek, M. Tyagi, J.R.D. Copley, C. M. Brown, J. J. Choi, S.-H. Lee, Phys. Chem. Chem. Phys. 17, 31278-31286 (2015).