Please post and forward to your groups ________________ Center for Excitonics Seminar Series Tuesday, April 3 , 2012 RLE Conference Room - 36-428 3:00 - 4:00pm "Singlet Fission" Josef Michl, Dept. of Chemistry and Biochemistry, University of Colorado, Boulder Abstract: Singlet fission is a process in which an excited singlet molecule shares some of its energy with a nearby ground state singlet molecule and both end up in their respective triplet excited states. By splitting one excitation into two, it has the potential for producing two electron-hole pairs from a single absorbed photon. A detailed analysis showed that this would enhance the limiting theoretical efficiency of a solar cell from the Shockley-Queisser limit of about 1/3 to almost 1/2. Only very few compounds have been shown to perform singlet fission efficiently. My research group collaborates with Nozik's group at NREL and Ratner's group at Northwestern in an effort to use first principles to devise design rules for new efficient singlet fission chromophores. Bio Prof. Josef Michl received his M.S. in Chemistry in 1961 at Charles University, and Ph.D. in 1965 at the Czechoslovak Academy of Sciences, Prague. In 1968, he did postdoctoral work at the University of Houston, University of Texas at Austin, Aarhus University, Denmark, and the University of Utah, where he stayed and became a full professor in 1975 and served as chairman in 1979-1984. In 1986-1990 he held the M. K. Collie-Welch Regents Chair in Chemistry at the University of Texas at Austin and subsequently moved to the University of Colorado, Boulder, CO, where he is Professor of Chemistry presently. He also holds an appointment in the Institute of Organic Chemistry and Biochemistry of Czech Academy of Sciences in Prague, Czech Republic since 2006. He is a member of the US National Academy of Sciences, the American Academy of Arts and Sciences, and the International Academy of Quantum Molecular Science, and an honorary member of the Czech Learned Society. Professor Michl has been the editor-in-chief of Chemical Reviews since 1984. He has co-authored five books on photochemistry and polarization spectroscopy, and over five hundred scientific papers in the areas of organic, inorganic, theoretical, and physical chemistry. His research has dealt with theoretical and experimental aspects of organic photochemical reactions, interpretation of linear and magnetic circular dichroism of cyclic pi-electron systems, preparation and characterization of organic and main-group inorganic reactive intermediates, linear chain conformations, theory of sigma electron delocalization and of spin-orbit coupling in biradicals, gas-phase cluster ions formed by sputtering, and several other topics. The primary emphasis in his current research is centered around the use of a molecular-size construction set for the assembly and characterization of surface-mounted molecular rotors, novel concepts in solar energy conversion, new structures and reactive intermediates in the chemistry of boron, silicon, and fluorine, catalysis with "naked" lithium cations, and the use of quantum chemical and experimental methods for better understanding of excited electronic states of saturated molecules. Light refreshments will be provided The Center for Excitonics is an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science and Office of Basic Energy Sciences