Infrared ultrafast optical probes of photoexcitations in ∏-conjugated organic semiconductors

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Publication Type Journal Article
School or College College of Science
Department Physics
Creator Vardeny, Zeev Valentine
Other Author Sheng, C. X.
Title Infrared ultrafast optical probes of photoexcitations in ∏-conjugated organic semiconductors
Date 2005
Description We measured the ultrafast dynamics of photoexcitations in a variety of semiconductor ∏-conjugated polymer films and solutions, in the spectral range from 0.13 eV to 1.05 eV and time domain from 100 fs to 800 ps. The measurements were made in the low signal regime, where the relative changes in transmission, ΔT/T <10-5. In pristine poly [2-methoxy-5(2'-ethyl-hexyloxy)-p-phenylene vinylene] (MEH-PPV) solution we found that the primary photoexcitations are excitons with a photoinduced absorption (PA) band PA1 at 1.0 eV. In pristine MEH-PPV film, however we found two PA bands, PA1 at 1.0eV and P1 at 0.3eV. We consider P1 to be due to a polarons that are photogenerated intrinsically via defects and/or impurities. When following the transient dynamics of PA1 in C60-doped PPV-based films we could easily measure the dynamics of exciton dissociation from the polymer chains onto the C60 molecules. We found the charge transfer time to range from about 100 fs to 100 ps, depending on the concentration of C60 molecules in the films.
Type Text
Publisher American Institute of Physics (AIP)
Volume 772
First Page 1081
Last Page 1082
DOI 10.1063/1.1994487
citatation_issn 0094243X
Subject Infrared ultrafast optical probes; Photoexcitations; Ultrafast dynamics; MEH-PPV
Subject LCSH Picosecond pulses; Conjugated polymers -- Optical properties; Organic semiconductors -- Optical properties
Language eng
Conference Title PHYSICS OF SEMICONDUCTORS: 27th International Conference on the Physics of Semiconductors - ICPS-27; 26-30 July 2004; Flagstaff, Arizona (USA)
Bibliographic Citation Sheng, C. X., & Vardeny, Z. V. (2005). Infrared ultrafast optical probes of photoexcitations in ∏-conjugated organic semiconductors. AIP Conference Proceedings, 772, 1081-2.
Rights Management (c)American Institute of Physics. The following article appeared in Sheng, C. X., & Vardeny, Z. V., AIP Conference Proceedings, 772, 2005 and may be found at
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Identifier ir-main,10064
ARK ark:/87278/s60v8x7g
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2021-05-06
ID 705714
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