When: 2pm on Friday Where: Mallinkrodt Divsion Room What: Dr. David Strubbe, a post-doc in the Grossman Group at MIT will be telling us about... Exciton self-trapping in the optical response of pentacene crystals from first principles ====================================================================== Pentacene is a prototypical organic semiconductor with optoelectronic and photovoltaic applications. It is known that the lowest-energy singlet excitation has a Stokes shift between absorption and emission of about 0.14 eV, but the deformation associated with this self-trapped exciton remains unknown. We begin with a calculation of the optical properties via the first-principles GW/Bethe-Salpeter (BSE) theory [ML Tiago, JE Northrup, and SG Louie, Phys. Rev. B 67, 115212 (2003); S Sharifzadeh, A Biller, L Kronik, and JB Neaton, Phys. Rev. B 85, 125307 (2012)]. We then study the self-trapping phenomenon via our reformulation of the Bethe-Salpeter excited-state forces approximation of Ismail-Beigi and Louie [Phys. Rev. Lett. 90, 076401 (2003)], which can describe the structural relaxation after optical excitation. -- Ryan Babbush | PhD Student in Chemistry (949) 331-3943 | babbush(a)fas.harvard.edu Harvard University | Aspuru-Guzik Research Group 12 Oxford Street, Box 400 | Cambridge, MA 02138 _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list _____________________________________________ Aspuru-list mailing list Aspuru-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-list