Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-17T21:51:25.189Z Has data issue: false hasContentIssue false
  • English
  • Français

Materials Engineering For Polarized Light Emitting Diodes

Published online by Cambridge University Press:  10 February 2011

G. Wegner ,
D. Neher ,
M. Remmers ,
V. Cimrova  and
M. Schulze
G. Wegner
Affiliation:
Max-Planck-Institut f. Polymerforschung, P.O. Box 3148, D-55021 Mainz, Germany
D. Neher
Affiliation:
Max-Planck-Institut f. Polymerforschung, P.O. Box 3148, D-55021 Mainz, Germany
M. Remmers
Affiliation:
Max-Planck-Institut f. Polymerforschung, P.O. Box 3148, D-55021 Mainz, Germany
V. Cimrova
Affiliation:
Max-Planck-Institut f. Polymerforschung, P.O. Box 3148, D-55021 Mainz, Germany
M. Schulze
Affiliation:
Max-Planck-Institut f. Polymerforschung, P.O. Box 3148, D-55021 Mainz, Germany
Get access

Abstract

Electroluminescent devices have been made from organo-soluble derivatives of poly(pphenylene). Solubility and processibility by the LB-technique is achieved by attaching alkoxy side groups to the backbone-p-phenylene units. These polymers are of the hairy-rod (HR) type. If transferred as monolayers from the air-water-interface, monodomain multilayers with large order parameters of chain orientation are obtained. A 130 nm thick LB-film of poly(2,5-diisopentoxy-pphenylene) shows blue photoluminescence at λmax = 3.08 eV (404 nm) with a tail extending to 2 eV. The anisotropy was (lII- l1)/ (l11, + l11)= 0.5. This LB-film between a transparent gold and an evaporated Al-electrode shows polarized light emission at E ≤ 6.107 V cm−1 with am=a λmax2.2 eV and an in-plane anisotropy of 0.54. Thin films obtained by spincoating of the same polymer show isotropic electroluminescence between ITO and Al-electrodes with an external quantum efficiency of about 0.03 %. Higher efficiencies up to 4 % were realized optimizing the device architecture and the electrodes. Photocrosslinkable sites are introduced as side groups to the poly(pphenylene) chain. This allows patterning of the LEDs. General features of the supramolecular architecture and typical defect structures occurring in films of polyconjugated macromolecules are discussed using prototypical polymers as examples. Important effects are chain segregation according to chain length and formation of disclinations.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 413: Symposium W – Electrical, Optical, and Magnetic Properties of Organic Solid State Materials III , 1995 , 23
Copyright
Copyright © Materials Research Society 1996

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

REFERENCES

1. Stamm, M., Fischer, E.W., Dettenmaier, M., Convert, P., Farad. Disc. Chem. Soc. 68, p. 263 (1979)Google Scholar
2. Wang, W., Lieser, G., Wegner, G., Liq. Cryst. 15, P 1 (1993)Google Scholar
3. Wang, W., Lieser, G., Wegner, G., Macromolecules 27, p. 1027 (1994)Google Scholar
4. Witteler, H., Lieser, G., Wegner, G., Schulze, M., Macromol. Chem. Rapid Commun. 14, p. 471 (1993)Google Scholar
5. Wegner, G., Thin Solid Films 216, p. 105 (1992)Google Scholar
6. Wegner, G., Mol. Cryst. Liq. Cryst. 235, p. 1 (1993)Google Scholar
7. Schwiegk, S., Vahlenkamp, Th., Xu, Y., Wegner, G., Macromolecules 25, p. 2513 (1992)Google Scholar
8. Wu, J.H., Lieser, G., Wegner, G., Adv. Mater. (1995) in pressGoogle Scholar
9. Rehan, M., Schlüter, A.D., Wegner, G., Feast, J., Polymer 30, p. 1060 (1989)Google Scholar
10. Th. Vahlenkamp, Wegner, G., Macromol. Chem. Phys. 195, p. 1933 (1994)Google Scholar
11. Cimrova, V., Remmers, M., Neher, D., Wegner, G., Adv. Mater. (1995) in pressGoogle Scholar
12. Rauscher, U., Bassler, H., Bradley, D.D.C., Hennecke, M., Phys. Rev. B 42, p. 9830 (1990)Google Scholar
13. Braun, D., Staring, E.G.J., CJ, R..Demandt, E., Rikken, G.L.J., Kessener, Y.A.R.R., Venhuizen, A.H.J., Synth. Met. 66, p. 75 (1994)Google Scholar
14. Brown, A.R., Greenham, N.C., Burroughes, J.H., Bradley, D.D.C., Friend, R.H., Burn, P.L., Kraft, A., Holmes, A.B., Chem. Phys. Lett. 200, p. 46 (1992)Google Scholar
15. Yokoyama, H., Science 256, p. 66 (1992)Google Scholar
16. Wittmann, H.F., Gruner, J., Friend, R.H., Spencer, G.W.C., Moratti, S.C., Holmes, A.B., Adv. Mat. 7, p. 541 (1995)Google Scholar
17. Cimrova, V., Neher, D., Synth. Meth., in pressGoogle Scholar
18. Tsutsui, T., Takada, N., Saito, S., Ogino, E., Appl. Phys. Lett. 65, p. 1868 (1994)Google Scholar
19. Dodabalapur, A., Rothberg, L.J., Miller, T.M., Kwock, E.W., Appl. Phys. Lett. 64, p. 2486(1994)Google Scholar
20. Lemmer, U., Hennig, R., Guss, W., Ochse, A., Pommerehne, J., Sander, R., Greiner, A., Mahrt, R.F., Bassler, H., Fledmann, J., Gobel, E.O., Appl. Phys. Lett. in pressGoogle Scholar
21. Cimrova, V., Neher, D., J. Appl. Phys., in pressGoogle Scholar