ABSTRACT
Traditional physical models assume that solar cells operate under quasi-static equilibrium conditions. A material absorbs a photon to generate a pair of excited state electrons, and the photoelectric conversion efficiency is limited by the excess energy thermal loss of carriers and the loss due to overcoming the electron-hole binding. The efficiency of a single-junction device is at most about 33%, known as the Shockley-Queisser limit. Utilizing low-cost designs to seek breakthrough photoelectric conversion schemes is an important challenge in the industry. For this purpose, our research group has developed ultrafast spectroscopy methods to study the photo-induced non-equilibrium processes in molecular photoelectric materials, exploring low-driving-energy exciton dissociation, singlet fission, and other excited state dynamics mechanisms that have the potential to break through the limits of traditional models.
BIOGRAPHY
Prof. Chunfeng Zhang currently works as a professor at the Department of Physics, Nanjing University, China. He obtained his B.Sc. and Ph.D. degrees in Physics from Fudan University in 2002 and 2007, respectively. Dr. Zhang has worked as a Postdoc Scholar at the Pennsylvania State University (2007-2010) and a visiting scholar at JILA, University of Colorado at Boulder (2015). His research interest focuses on understanding the light-matter interaction in semiconductor nanostructures and organic optoelectronic materials by using transient magneto-optical and two-dimensional electronic spectroscopic approaches.
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