Marlon G. Cummings
Lab Manager, Aspuru-Guzik Group
Mallinckrodt M112
Department of Chemistry and Chemical Biology
Harvard University
12 Oxford Street
Cambridge, MA 02138
617-496-9964
617-496-9411 (fax)
http://aspuru.chem.harvard.edu/
---------- Forwarded message ----------
From: Catherine M Bourgeois <cmbourg(a)mit.edu>
Date: Wed, Jan 14, 2015 at 8:23 AM
Subject: [Aspuru-Guzik group list] FW: Excitonics Seminar, TOMORROW, Jan
15, 3:30 pm/ 4-270
To: "efrc-all(a)mit.edu" <efrc-all(a)mit.edu>
Please post and forward to your groups
________
CENTER FOR EXCITONICS SEMINAR
“Non-contact Nondestructive Probing of Charge Carrier Conductivity in
Organic Materials and their Interfaces”
*January 15, 2015 at 3:30pm/ 4-270*
*Shu Seki, **Osaka University*
[image: seki_01]
*Abstract:*
Understanding charge carrier transport processes at interfaces is one of
the most important subjects in organic electronics. Charge carriers are
injected or extracted through metal/semiconductor interfaces in most
electronic devices, while carrier transport occurs at
insulator/semiconductor interfaces rather than in the bulk in the major
organic electronic devices.1,2 However, analytical techniques for
evaluating such interfacial carrier transport phenomena are still limited,
and this remains a challenging issue. We have recently reported a
technique, referred to as time-resolved microwave conductivity (TRMC)3, and
the system has been extended into field-induced TRMC that combines charge
carrier injection via gate bias applied into working devices and
microwave-based non-contact probing of intrinsic and local charge carrier
motion. The schematic diagram of the set of apparatus is given in figure 1.
Using this technique, it was determined that a Au/pentacene/PMMA/SiO2/Au
MIS device had hole and electron mobilities of 6.3 and 0.3 cm2V–1s–1,
respectively.4,5 Non-contact, fully experimental evaluation of intra-domain
carrier mobility at interfaces is quite unprecedented and is a
characteristic feature of this system. In this paper, we further report
that the FI-TRMC technique can distinguish between mobile charge carriers
at the interface and immobile charges trapped at defects, thus enabling
quantification of both the charge carrier mobility and the density of trap
sites at insulator-semiconductor interfaces, and discuss also on the
extraordinary mobile charge carriers at the interfaces on highly developed
planner p-conjugated systems such as graphene and its derivatives.
References: 1) G. Horowitz and P. Delannoy, J. Appl. Phys. 70, 469 (1991).
2) H. Klauk, Chem. Soc. Rev. 39, 2643 (2010). 3) S. Seki, et al., Phys.
Chem. Chem. Phys. 16, 11093 (2014); Acc. Chem. Res. 45, 1193 (2012); Nature
Commun. 5, 3718 (2014); Nature Commun. 4, 2694 (2013); Nature Commun. 4,
1691 (2013); 4) S. Seki, et al., Sci. Rep. 3, 3182 (2013). 5) W. Choi, T.
Miyakai, T. Sakurai, A. Saeki, M. Yokoyama, S. Seki, Appl. Phys. Lett. 105,
019430 (2014)
Bio:
Shushi Seki received his BS (1991) and MS (1993) in Engineering at the
University of Tokyo. In 1995, he worked in the Chemistry Division at the
Argonne National Laboratory . He was Assistant Professor at Osaka
University, Japan, from 1995 – 2001 while earning his PhD in 2001. From
2001 – 2007, he was an Associate Professor at the Institute of Scientific
and Industrial Research and from 2007-2009, at the Department of Applied
Chemistry, both at Osaka University. Currently, he is Professor in the
Department of Applied Chemistry Graduate School of Engineering at Osaka and
his area of research is in condensed matter physical chemistry.
*Light refreshments will be served*
*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*
_____________________________________________
Aspuru-list mailing list
Aspuru-list(a)lists.fas.harvard.edu
https://lists.fas.harvard.edu/mailman/listinfo/aspuru-list