Publication Type |
Journal Article |
School or College |
College of Science |
Department |
Physics |
Creator |
Vardeny, Zeev Valentine |
Other Author |
Liess, M.; Gontia, I.; Masuda, T.; Yoshino, K. |
Title |
Photoexcitations in disubstituted acetylene polymers |
Date |
1997 |
Description |
We have used a variety of optical techniques to study the photoexcitations dynamics in several disubstituted acetylene polymer thin films. We found that although these polymers have a degenerate ground state, as determined by iodine doping and C6Q photodoping, they show strong photoluminescence (PL) in the blue/green spectral range with high quantum efficiency (QE) in thin films. The cw photo modulation spectrum contains a single photoinduced absorption (PA) band at 1.7 eV with monomolecular recombination kinetics with a lifetime of 25 ms. PA detected magnetic resonance (PADMR) shows that this PA band is related to spin 1/2 excitations, which therefore identifys it as due to neutral soliton antisoliton pairs (S°, s° ), similar to the 1.35 eV PA band in t-(CH)x . No triplet PADMR signal was observed and we therefore conclude that triplet excitations are unstable in disubstituted acetylene polymers, even though singlet excitons relatively stable. We consider therefore a possible S° photogeneration mechanism via singlet to triplet intersystem crossing, followed by triplet exciton decomposition into S° S° pairs. Also we detected polarons in a degenerate ground state polymer for the first time. |
Type |
Text |
Publisher |
International Society for Optical Engineering (SPIE) |
Volume |
3145 |
First Page |
179 |
Last Page |
189 |
DOI |
10.1117/12.295529 |
citatation_issn |
0277786X |
Subject |
Photoexcitations; Disubstituted acetylene polymers; Trans-Polyacetylene; Electron-electron interactions |
Subject LCSH |
Luminescence; Thin films -- Optical properties; Acetylene compounds -- Optical properties |
Language |
eng |
Conference Title |
Optical Probes of Conjugated Polymers; Monday 28 July 1997; San Diego, CA, USA |
Bibliographic Citation |
Liess, M., Gontia, I., Masuda, T., Yoshino, K., & Vardeny, Z. V. (1997). Photoexcitations in disubstituted acetylene polymers. SPIE 3145, 179-89. |
Rights Management |
(c)Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. http://dx.doi.org/10.1117/12.295529 |
Format Medium |
application/pdf |
Format Extent |
1,932,073 bytes |
Identifier |
ir-main,9863 |
ARK |
ark:/87278/s67s8678 |
Setname |
ir_uspace |
ID |
705453 |
Reference URL |
https://collections.lib.utah.edu/ark:/87278/s67s8678 |