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Discotic Liquid Crystalline Porphyrins: Photophysical and Photoelectrical Properties of Large-Area Crystalline Films

Published online by Cambridge University Press:  25 February 2011

Brian A. Gregg ,
Marye Anne Fox  and
Allen J. Bard
Brian A. Gregg
Affiliation:
University of Texas at Austin, Dept. of Chemical Engineering, Austin, TX 78712.
Marye Anne Fox
Affiliation:
University of Texas at Austin, Dept. of Chemistry, Austin, TX 78712.
Allen J. Bard
Affiliation:
University of Texas at Austin, Dept. of Chemistry, Austin, TX 78712.
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Abstract

Porphyrins exhibiting discotic liquid crystalline phases have been developed in order to prepare thin, large-area, crystalline films of molecular conductors. A series of octaalkylporphyrins bearing different side chains have been synthesized including some with electron-withdrawing substituents at the meso positions. The photophysical properties of thin films of these compounds are a strong function of the film order (crystallinity). A substantial and persistent photovoltaic effect was achieved (e.g., Voc = 0.3 V, jsc = 0.4 mA/cm2 under white light, 150 mW/cm2) in capillary-filled symmetrical cells with indium-tin oxide electrodes. A model based on kinetically-controlled asymmetric exciton dissociation leading to photoinjection at the illuminated interface is presented to explain these results. This appears to be the first unambiguous example of a photovoltaic cell controlled entirely by interfacial kinetics. The predominance of the photoinjection process in these cells is attributed to the single-crystal-like character of the porphyrin films.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 173: Symposium Q – Advanced Organic Solid State Materials , 1989 , 199
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1. Gregg, B. A., Fox, M. A., Bard, A. J., J. Chem. Soc., Chem. Commun., 1143 (1987).Google Scholar
2. Gregg, B. A., Fox, M. A., Bard, A. J., J. Am. Chem. Soc., 111, 3024 (1989).Google Scholar
3. Gregg, B. A., Fox, M. A., Bard, A. J., J. Phys. Chem., 93, 4227 (1989).CrossRefGoogle Scholar
4. for a review, see: Dolphin, D., Ed. The Porphvrins.Vols. I-VII, (Academic Press, New York, 1978).Google Scholar
5. Marks, T. J., Science, 227, 881 (1985), and references therein.CrossRefGoogle Scholar
6. Davydov, A. S., Theory of Molecular Excitons (Plenum Press, New York, 1971).Google Scholar
7. Gouterman, M., Holten, D., Lieberman, E., Chem. Phys. 25, 139 (1977).Google Scholar
8. Geacintov, N., Pope, M., Kallman, H., J. Chem. Phys., 41, 2639 (1966).Google Scholar
9. Gregg, B. A., Fox, M. A., Bard, A. J., J. Phys. Chem. in press.Google Scholar
10. LeBlanc, O. H., in Physics and Chemistry of the Organic Solid State. Vol. 3, edited by Fox, D., Labes, M. M., and Weissberger, A. (Interscience, New York, 1967).Google Scholar
11. Smith, R. A., Semiconductors. 2nd Ed. (Cambridge University Press, Cambridge, 1978).Google Scholar
12. Pope, M., Swenberg, C. E., Electronic Processes in Organic Solids. (Oxford University Press, New York, 1982).Google Scholar
13. Lyons, L. E., in Physics and Chemistry of the Organic Solid State. Vol. 1. edited by Fox, D., Labes, M. M., and Weissberger, A. (Interscience, New York, 1963).Google Scholar
14. Helfrich, W., in reference 10.Google Scholar
15. Gutmann, F., Lyons, L. E., Organic Semiconductors. Part A (Robert E. Krieger Publishing Co., Malabar, FLA., 1981).Google Scholar
16. Kallman, H., Pope, M., J. Chem. Phys., 30, 585 (1959).Google Scholar
17. Hall, K. J., Bonham, J. S.. Lyons, L. E.. Aust. J. Chem., 31, 1661 (1978).Google Scholar
18. Bonham, J. S.. Aust. J. Chem., 29, 2123 (1976).Google Scholar
19. Kommandeur, J., J. Phys. Chem. Solids, 22, 339 (1961).Google Scholar
20. Martin, M., Andre, J.-J., Simon, J., Nouv. J. Chim., 1, 485 (1981).Google Scholar
21. Yamashita, K., Harima, Y., Iwashima, H. J., J. Phys. Chem., 91, 3055 (1987).Google Scholar
22. Fan, F.-R., Faulkner, L. R., J. Chem. Phys. 69, 3334 (1978); 69, 3341 (1978).Google Scholar
23. Loutfy, R. O., Sharp, J. H., Hsiao, C. K., Ho, R., J. Appl. Phys., 52, 5218 (1981).Google Scholar
24. Loutfy, R. O., Hsiao, C. K., Can. J. Phys., 59, 727 (1981).Google Scholar
25. Gerischer, H., Lübke, M., Bressel, B., J. Electrochem. Soc. 130, 2112 (1983).Google Scholar
26. Mott, N. F., Gurney, R. W., Electronic Processes in Ionic Crystals. 2nd Ed. (Dover, New York, 1964), p. 192.Google Scholar