[LA-SiGMA] LASiGMA Seminar at Tulane, today, at 3:00 pm - Matt Sfeir

[sjlee at cct.lsu.edu]

Dear All,

As reminder, Dr. Matt Sfeir of Brookhaven National Laboratory, will be  
giving a talk, today at 3:00 pm in room 600 at the Lindy Boggs Building,
Tulane University. The title of his talk is " Novel Singlet Fission
Processes in Organic Semiconductors."

Please see below for more details.

Regards,
Shelley


Quoting shelley lee <sjlee at cct.lsu.edu>:

> Dear All,
>
> Dr. Matt Sfeir of Brookhaven National Laboratory, will be giving a talk,
> Wednesday, November 5th at 3:00 pm in room 600 at the Lindy Boggs Building,
> Tulane University. The title of his talk is " Novel Singlet Fission
> Processes in Organic Semiconductors."
>
> Abstract:
> Singlet fission is a form of multiple exciton generation in which two
> triplet excitons are produced from the decay of a photoexcited singlet
> exciton. In a small number of organic materials, most notably pentacene,
> this conversion process has been shown to occur with unity quantum yield on
> sub-ps timescales. However, a poorly understood mechanism for fission along
> with strict energy and geometry requirements have so far limited the
> observation of this process to a few classes of organic materials, with only
> a subset of these showing both efficient fission and long-lived triplets.
> Here, we utilize novel organic materials to investigate how the efficiency
> of the fission process depends on the coupling and the energetic driving
> force between chromophores in both intra- and intermolecular singlet fission
> materials. We report for the first time intramolecular fission yields above
> 100% and demonstrate how the triplet yield can be directly quantified as a
> function of energetic driving force and degree of charge transfer character
> of the singlet state. These results allow us to gain mechanistic insight
> into the fission process and suggest general strategies for generating new
> materials that can undergo efficient fission.
>
> Biography:
> My research focuses on using optics to probe the electronic structure and
> interfacial interactions among novel nanoscale materials. This includes
> measurements of fundamental carrier dynamics, photo physics of excitons and
> other bound states, electron-phonon coupling, and as well as charge and
> energy transfer processes. My interests include the development of broadband
> time-resolved and optoelectronic spectroscopies and their application to
> evaluate the potential of novel materials in light harvesting devices.  My
> recent work has focused on exciton conversion processes in low band gap
> organic semiconductors and the in-situ dynamics of nanostructured
> heterogeneous photo catalytic materials. I received my Ph.D. in Chemical
> Physics in 2005 from Columbia University under the supervision of Prof.
> Louis Brus and have been a staff member at the Center for Functional
> Nanomaterials since 2009.
>
> UNO - 234, Liberal Arts Building
> LATech - 122, Nethken Hall
> SUBR - 211 J.B. Moore Hall
> Xavier - 226 Qatar Pavillion
> LSU - 1008B Digital Media Center
>
> Please note, this seminar will ONLY be accessible through HD
> videoconferencing. Adobe connect will NOT be offered.
>
> Regards,
> Shelley Lee
> Project Coordinator
> 225-578-0465
>
>
>
>