When: Friday April 14 from 11:30 AM to 12:30 PM
Where: Cabot Division Room at Mallinckrodt
What: Group meeting by Sule
" The story of DA2T and some tricky charge transport parameters"
formal abstract:
The design and screening of novel organic semiconductors in silico,
prior to undertaking chemical synthesis could create new opportunities
for rational semiconductor design. We report of a theoretical
screening study of eight novel derivatives of the high-performance
dinaphtho[2,3-b:2’,3’-f]thieno[3,2-b]thiophene semiconductor.
Recently, this molecule has demonstrated mobilities as high as 8.3
cm2V-1s-1. Our study identifies a novel compound expected to
demonstrate a two-fold improvement in mobility over the parent
molecule. Synthetic and electrical characterisation of the compound is
reported with single crystal field-effect transistors, indeed showing
a two-fold improvement in mobility to 13.7 cm2V-1s-1. This is one of
the very few organic semiconductors to show mobilities greater than 10
cm2V-1s-1.
informal abstract:
DA2T is a novel high-mobility organic semiconductor for OFET
applications discovered by theoreticians. But theoreticians cannot
publish new molecules without experimental support easily. We were
lucky to have it synthesized and indeed show an exceptional mobility.
We had a small library of 7 molecules and could eliminate 5 of them
based on only the molecular parameters. For the remaining two we
optimized crystal structures to see how they pack and then calculated
the electronic couplings among the packed molecules. Finally based on
classical charge transfer theories, for DA2T we estimated a mobility
which would be higher than pentacene as well as its parent compound.
This study provides insights into the tricky world of charge transfer
parameters in organic molecular crystals and provide some guidance
towards screening of millions of molecules over the World Community
Grid: The Clean Energy Project.--
Joel Yuen-Zhou
PhD candidate in Chemical Physics
Harvard University CCB,
12 Oxford St. Mailbox 107,
Cambridge, MA, USA.