Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-25T04:50:01.075Z Has data issue: false hasContentIssue false
  • English
  • Français

Advanced Characterization of the Electronic Structure of MEH-PPV

Published online by Cambridge University Press:  01 February 2011

David Keith Chambers  and
Sandra Selmic
David Keith Chambers
Affiliation:
Louisiana Tech UniversityInstitute for Micromanufacturing 911 Hergot Ave., Ruston, LA 71272,U.S.A.
Sandra Selmic
Affiliation:
Louisiana Tech UniversityInstitute for Micromanufacturing 911 Hergot Ave., Ruston, LA 71272,U.S.A.
Get access

Abstract

In this paper, we present research results that explore the basic molecular structure, orientation, and electrical properties of the conjugated polymer poly(2-methoxy-5- (2,9-ethyl-hexyloxy)-1,4-phenylenevinylene) (MEH-PPV). The bandgap structure of MEH-PPV was investigated through optical absorption and emission spectra, and ultraviolet photoemission spectroscopy (UPS). Based on the optical absorption of MEH-PPV, the π-π* bandgap energy is 2.14eV. The emission spectrum of ITO/MEH-PPV/Al light emitting diode has a peak at 590nm in wavelength which corresponds to photon energies of 2.1eV. By using ultraviolet synchrotron radiation to investigate the highest occupied molecular orbitals (HOMO) of the MEH-PPV, the relative change in photoemission cross-section for various electron states was measured. The HOMO to Fermi level gap obtained from UPS spectra is about 3eV. The UPS measurements include angle-resolved and incident energy dependent spectra. Some indication of bulk film orientation was inferred by dispersion of incident energy dependent UPS. Disparities in these spectra imply some role for defect states, extrinsic carrier involvement, or Fermi-level pinning.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 871: Symposium I – Organic Thin-Film Electronics , 2005 , I6.20
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Burroughes, J. H., Bradley, D. D. C., Brown, A. R., Marks, R. N., Mackay, K., Friend, R. H., Burns, P. L. and Holmes, A. B., Nature 347, 539 (1990).Google Scholar
2 Braun, D. and Heeger, A., Appl. Phys. Lett. 58, 1982 (1991).Google Scholar
3 Wudl, Fred and Srdanov, G., US Patent #5,189,136 (23 Februrary 1993).Google Scholar
4 Skotheim, T., Ed.; Handbook of Conducting Polymers; (Marcel Dekker, Inc., New York, 1986).Google Scholar
5 Wilbourn, K., Murray, R. W., J. Phys. Chem. 92, 3642 (1988).Google Scholar
6 Hagler, T. W., Pakbaz, K., Voss, K. F., and Heeger, A. J., Phys. Rev. B, 44, 8652 (1991).Google Scholar
7 Friend, R. H., Gymer, R. W., Holmes, A. B., Burroughes, J. H., Marks, R. N., Taliani, C., Bradley, D. D. C., D. A. Dos Santos, Bredas, J. L., Logdlund, M., and Salaneck, W. R., Nature 397, 121 (1999).Google Scholar
8 Wohlgenannt, M. Jiang, X. M. and Vardeny, Z. V. Phys. Rev. B 69, 241204 (2004).Google Scholar
9 Salhi, F., Collard, D.M., Advanced Materials 15, 81 (2003).Google Scholar
10 Cameron, C., PhD. Thesis, Memorial University of Newfoundland, 2000.Google Scholar
11 Wong, K. S., Bradley, D.D.C., Hayes, W., Ryan, J.F., Friend, R.H., Lindenberger, H. and Roth, S., J. Phys. C: Solid State Phys. 20 L187 (1987).Google Scholar
12 Gartstein, Yu. N., Rice, M. J. and Conwell, E. M., Phys. Rev. B 52, 1683 (1995).Google Scholar
13 Shim, Hong-Ku and Jin, Jung-Il, Advances in Polymer Science 158, 193 (2002).Google Scholar
14 Spreitzer, H., Becker, H., Kluge, E., Kreuder, W., Schenk, H., Demandt, R. and Schoo, H., Advanced Materials 10, 1340 (1999).Google Scholar
15 Garnier, F., Angewandte Chemie International Edition in English 28, 513 (1989).Google Scholar
16 Garay, R. O., Mayer, B., Karasz, F.E. and Lenz, R.W., Journal of Polymer Science Part A: Polymer Chemistry 33, 525 (1994).Google Scholar
17 Hayes, G. R., Samuel, I. D. W., and Phillips, R. T., Phys. Rev. B 52, R11569 (1995).Google Scholar
18 Mizes, H. A. and Conwell, E. M., Phys. Rev. Lett. 70, 1505 (1993).Google Scholar
19 Costa, P. Gomes da, Dandrea, R.G. and Conwell, E.M., Phys. Rev. B 47, 1800 (1993).Google Scholar
20 Arkhipov, V. I., Bässler, H., Deussen, M., Göbel, E. O., Kersting, R., Kurz, H., Lemmer, U. and Mahrt, R. F., Phys. Rev. B 52, 4932 (1995).Google Scholar
21 Hagler, T.W., Pakbaz, K., Voss, K.F., and Heeger, A. J., Phys. Rev. B 44, 8652 (1991).Google Scholar
22 Kuroda, S., Noguchi, T. and Ohnishi, T., Phys. Rev. Lett. 72, 286 (1994).Google Scholar
23 Chambers, D.K., Karanam, S., Qi, D., Selmic, S., Losovyj, Y.B., Rosa, L.G. and Dowben, P.A., Applied Physics A 80, 3, 483 (2005).Google Scholar
24 Fahlman, M., Bröms, P., The Journal of Chemical Physics 102, 8167 (1995).Google Scholar
25 Caruso, A.N., Rajesh, R., Gallup, G., Redepenning, J., and Dowben, P.A., J. Phys. Condens. Matter 16, 845 (2004).Google Scholar
26 Choi, J., Chipara, M., Xu, B., Yang, C.S., Doudin, B., and Dowben, P.A., Chem. Phys. Lett. 343, 193 (2001).Google Scholar
27 Dowben, P.A., LaGraffe, D., and Onellion, M., J. Phys. Cond. Matter 1, 6571 (1989).Google Scholar
28 Nguyen, T., Martini, I.B., Liu, J. and Schwartz, B.J., J. Phys. Chem. B, 104, 237 (2000).Google Scholar
29 Campbell, I.H., Hagler, T.W., Smith, D.L., and Ferraris, J.P., Phys. Rev. Lett., 76, 1900 (1996).Google Scholar