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Light Emitting Electrochemical Cells as Mixed Ionic Electronic Conductors

Published online by Cambridge University Press:  15 February 2011

I. Riess
Affiliation:
Physics Department, Technion-Israel Institute of Technology, Haifa 32000, Israel, riess@tx.technion.ac.il
D. Cahen
Affiliation:
Weizmann Institute of Science, Rehovot 76100, Israel, cscahenl@weizmann.weizmann.ac.il
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Abstract

Polymer electrochemical cells have been reported to emit light. The current and light output increase rapidly with voltage, apparently beyond 2V. The polymer is an ionic conductor as well as an electronic (electron/hole) conductor, i.e. a mixed ionic-electronic conductor (MIEC).

The I-V relations are explained here to be those of an MIEC of a particular defect model placed between two ion blocking electrodes. This MIEC defect model assumes a large concentration of mobile ions and small concentrations of electrons and holes. A p and an n region are formed in the MIEC. However, there is no space charge within the MIEC and it stays neutral. The resulting I-V relations are exponential. A good fit to the experimental data is obtained when electrode over-potential and heating of the polymer under current are taken into consideration.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. Pei, Q., Yu, G., Zhang, C., Yang, Y. and Heeger, A.J., Science, 269 1086 (1995).Google Scholar
2. Yang, Y., Pei, Q. and Heeger, A.J., J. Appl. Phys. 79 934 (1996).Google Scholar
3. Yu, G., Pei, Q. and Heeger, A.J., Appl. Phys. Lett. 70 934 (1997).Google Scholar
4. Bar-Lev, A., Semiconductors and Electronic Devices, 3rd Ed. Prentice Hall, 1993, pp. 412413.Google Scholar
5. Partridge, R.H., Polymer 24 755 (1983).Google Scholar
6. Barrow, 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 (London) 347 539 (1990).Google Scholar
7. Sheats, J.R., Antoniadis, H., Heuscher, M., Leonard, W., Miller, J., Moon, R., Roitman, D. and Stocking, A., Science, 273 884 (1996).Google Scholar
8. Parker, I.D., J. Appl. Phys. 75 1656 (1994).Google Scholar
9. Brown, D. and Heeger, A.J., Appl. Phys. Lett. 58 1982 (1991).Google Scholar
10. Scrosati, B., Polymer Electrodes, in: Solid State Electrochemistry, Bruce, P.G. Ed., Cambridge Univ. Press, 1995, Chap. 9, pp 229263.Google Scholar
11. Kanneko, M., Photoelectric Conversion by Polymeric and Organic Materials, in: Handbook of Organic Conductive Molecules and Polymers, Vol. 4, Nalwa, H.S. ed., John Wiley and Sons, 1997, Chap. 13, pp. 661696.Google Scholar
12. Shriver, D.F. and Bruce, P.G., Polymer Electrolytes I, General Principles, in: Solid State Electrochemistry, Bruce, P.G. Ed., Cambridge Univ. Press, 1995, Chap. 9, pp 229263.Google Scholar
13. Riess, I., Solid State Ionics, 75, 59 (1995).Google Scholar
14. Cahen, D. and Chernyak, L., Adv. Mater. 9 861 (1997).Google Scholar
15. Riess, I., J. Phys. Chem. Solids, 47 129 (1986).Google Scholar
16. Riess, I., Phys. Rev. B 35 5740 (1987).Google Scholar
17. Riess, I., Solid State Ionics, 69 43 (1994).Google Scholar
18. Riess, I. and Cahen, D., J. Appl. Phys. 82 3147 (1997).Google Scholar
19. Mello, J.C. de, Tessler, N., Graham, S.C. and Friend, R.H., Phys. Rev. B 57 12951 (1998).Google Scholar
20. Smith, D.L., J. Appl. Phys. 81 2869 (1997).Google Scholar
21. Yang, Y. and Pei, Q., Appl. Phys. Lett. 68 2708 (1996).Google Scholar
22. Dick, D.J., Heeger, A.J., Yang, Y. and Pei, Q., Adv. Mater. 8 985 (1996).Google Scholar