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Magnetoresistance and Magnetic Field Effect on Electroluminescence in Polyfluorene OLEDs

Published online by Cambridge University Press:  01 February 2011

Govindarajan Veeraraghavan
Affiliation:
[email protected], University of Iowa, Department of Electrical and Computer Engineering, 188 IATL, University of Iowa, Iowa City, IA, 52242, United States
Tho Duc Nguyen
Affiliation:
[email protected], University of Iowa, Department of Physics and Astronomy, Optical Science and Technology Center, 188 IATL, University of Iowa,, Iowa City, IA, 52242, United States
Yugang Sheng
Affiliation:
[email protected], University of Iowa, Department of Physics and Astronomy, Optical Science and Technology Center, 188 IATL, University of Iowa, Iowa City, IA, 52242, United States
Omer Mermer
Affiliation:
[email protected], University of Iowa, Department of Physics and Astronomy, Optical Science and Technology Center, 188 IATL, University of Iowa, Iowa City, IA, 52242, United States
Markus Wohlgenannt
Affiliation:
[email protected], University of Iowa, Department of Physics and Astronomy, Optical Science and Technology Center, 188 IATL, University of Iowa, Iowa City, IA, 52242, United States
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Abstract

We report on the experimental observation of large magnet field effect (MFE) on current and electroluminescence (EL) in polyfluorene organic light emitting diodes (OLEDs). We provide a comprehensive overview of the observed MFE. To the best of our knowledge, the mechanism causing these MFE is currently not known. Moreover, we show that these experiments do not allow determination whether the MFE acts on the carrier density or carrier mobility making any attempt of explaining it ambiguous. As a remedy, we performed magnetoresistance measurements in hole-only OLEDs and show that the MFE acts on the carrier mobility rather than carrier density.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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References

1 Friend, R. H. et al. Nature, 397, 121128, 1999.Google Scholar
2 Brabec, C. J., Sariciftci, N. S. and Hummelen, J. C., Adv. Func. Mat., 11, 1526, 2001.Google Scholar
3 Dimitrakopoulos, C. D. and Malenfant, P. R. L., Adv. Mat., 14, 99117, 2002.Google Scholar
4 Kalinowski, J. et al. Chem. Phys. Lett., 380, 710, 2003.Google Scholar
5 Davis, A. H. and Bussmann, K., J. Vac. Sci. & Techn. A, 22, 18851891, 2004.Google Scholar
6 Yoshida, Y.,Fujii, A., Ozaki, M., Yoshino, K., and Frankevich, E. L., Mol. Cryst. Liqu. Cryst., 426, 17, 2005.Google Scholar
7 Francis, T. L., Mermer, O., Veeraraghavan, G., and Wohlgenannt, M., New J. Phys., 6, 185, 2004.Google Scholar
8 Mermer, O., Veeraraghavan, G., Francis, T. L., Sheng, Y., Nguyen, D. T. and Wohlgenannt, M., Physical Review B, 72, 205202, 2005 Google Scholar
9 Mermer, O., Veeraraghavan, G., Francis, T. L. and Wohlgenannt, M., Solid State Commun., 134, 631, 2005.Google Scholar
10 Veeraraghavan, G. et al. in Organic Thin-Film Electronics, edited by Arias, A.C., Tessler, N., Burgi, L., and Emerson, J.A. (Mater. Res. Soc. Symp. Proc. 871E, Warrendale, PA, 2005), I1.8.Google Scholar
11 At the date this paper was written, URLs or hotlinks referenced herein were deemed to be useful supplementary material to this paper. Neither the author nor the MRS warrants or assumes liability for the content or availability of URLs referenced in this paper.Google Scholar
12 Blom, P.W.M. et al. , Mater. Sci. Eng. R.: Rep. 27, 5394, 2000.Google Scholar
13 Pope, Martin and Swenberg, Charles E., Electronic Processes in organic crystals and polymers, 2nd Edition (Oxford Science publications, New York, 1999) p1118.Google Scholar
14 Campbell, A. J., Bradley, D. and Antoniadis, H, J. Appl. Phys., 89, 33433351, 2001.Google Scholar
15 Kalinowski, J., J. Phys. D: Appl. Phys., 32, R179–R249, 1999.Google Scholar