Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T15:59:29.158Z Has data issue: false hasContentIssue false
  • English
  • Français

Conjugated Polymer Fluorescence: Interplay Of Correlations And Alternation

Published online by Cambridge University Press:  16 February 2011

Z. G. Soos ,
D. S. Galvão ,
S. Etemad  and
R. G. Keplero
Z. G. Soos
Affiliation:
Department of Chemistry, Princeton University, Princeton, NJ 08544
D. S. Galvão
Affiliation:
Bell Communications Research, Red Bank, NJ 07701 Universidade Estadual de Campinas, Departamento de Fisica Aplicada, 13081, Campinas, SP, Brazil
S. Etemad
Affiliation:
Bell Communications Research, Red Bank, NJ 07701
R. G. Keplero
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
Get access

Extract

Conjugated polymers have been intensively studied in connection with high conductivity on doping, large nonlinear optical responses in their semiconducting state, and recently[1] as novel light-emitting diodes (LEDs). Many different polymers are realized in Fig. 1 on varying the substituents R, including the best characterized examples[2,3] that have centrosymmetric conjugated backbones in their idealized extended geometry. The PS and PPV families fluoresce strongly, the PT family Moderately, and the PDA's or PA hardly at all. We have related [4,5] polymer fluorescence to the nature of the lowest singlet excited state, Si, which in C2h symmetry is either a dipole-allowed Bu or a two-photon allowed Ag state. Since the ground state is Ag, S1 is either 1B or 2A and fluorescence requires E (1B) < E(2A). The idea is simply that radiationless decay wins out for the low excitation energies and many vibrational degrees of freedom of conjugated polymers unless Si has a strong transition dipole to the ground state.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 328: Symposium Q – Electrical, Optical, and Magnetic Properties of Organic Solid State Materials , 1993 , 383
Copyright
Copyright © Materials Research Society 1994

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. Burroughs, J.H., Bradley, D.D.C., Brown, A.R., Marks, R.N., McKay, K., Friend, R.H., Burns, P.L., and Holmes, A.B., Nature 347, 539 (1990).CrossRefGoogle Scholar
2. Heeger, A.J., Kivelson, S., Schrieffer, J.R., and Su, W. P., Rev. Mod. Phys. 60, 781 (1988).CrossRefGoogle Scholar
3. See Proceedings of the International Conference on the Science and Technology of Synthetic Metals, Tübingen, Germany (1990), Synth. Met. 41–43 (1991); and Gotenborg, Sweden (1992), Synth. 55–57 (1993).Google Scholar
4. Soos, Z.G., Etemad, S., Galvão, D.S., and Ramasesha, S., Chem. Phys. Lett. 194, 341 (1992).Google Scholar
5. Soos, Z.G., Galvão, D.S., and Etemad, S., Adv. Mat. (in press).Google Scholar
6. Etemad, S. and Soos, Z.G., in Spectroscopy of Advanced Materials (Clark, R.J.H. and Hester, R.E., eds., John Wiley & Sons Ltd., New York, 1991) Chapter 2.Google Scholar
7. McWilliams, P.C.M., Hayden, G.W., and Soos, Z.G., Phys. Rev. B 43, 9777 (1991).CrossRefGoogle Scholar
8. Kepler, R.G. and Soos, Z.G., Phys. Rev. B 43, 12530 (1991).Google Scholar
9. Soos, Z.G., Ramasesha, S., and Galvão, D.S., Phys. Rev. Lett. 71, 1609 (1993).Google Scholar
10. Lieb, E.H. and Wu, F.Y., Phys. Rev. Lett. 20, 1445 (1968);CrossRefGoogle Scholar
Ovchinnikov, A.A., Sov. Phys. JETP 30, 1100 (1970).Google Scholar
11. Salem, L., The Molecular Orbital Theory of Conjugated Systems, (Benjamin, New York, 1965);Google Scholar
Schulten, K., Ohmine, I., and Karplus, M., J. Chem. Phys. 64, 4422 (1976).Google Scholar
12. Hudson, B.S., Kohler, B.E., and Schulten, K., Excited States, Vol. 6 (Lim, E., ed., Academic Press, New York, 1982) p. 1.Google Scholar
13. Soos, Z.G. and Hayden, G.W., in Electroresponsive Molecular and Polymeric Systems (Skotheim, T., ed., Marcel Dekker, New York, 1988) p. 197.Google Scholar
14. Kohler, B.E., Spangler, C., and Westerfield, C., J. Chem. Phys. 89, 5422 (1980).CrossRefGoogle Scholar
15. Baker, C.J., Gelsen, O.M., and Bradley, D.D.C., Chem. Phys. Lett. 210, 127 (1993).CrossRefGoogle Scholar
16. Ramasesha, S., Galvão, D.S., and Soos, Z.G., J. Phys. Chem. 97, 2823 (1993);Google Scholar
Soos, Z.G., Ramasesha, S., Galvão, D.S., and Etemad, S., Phys. Rev. B 47, 1742 (1993).CrossRefGoogle Scholar
17. Soos, Z.G. and Hayden, G.W., Chem. Phys. 143, 199 (1990).Google Scholar
18. Kohler, B.E. and Schilke, D.E., J. Chem. Phys. 86, 5214 (1987).Google Scholar
19. Townsend, P.D., Fann, W., Etemad, S., Baker, G.L, Soos, Z.G., and McWilliams, P.C.M., Chem. Phys. Lett. 180, 485 (1990).CrossRefGoogle Scholar
20. Lawrence, B.L., Torruellas, W.E., Stegeman, G.I., Etemad, S., and Baker, G.L., unpublished.Google Scholar
21. Periasamy, N., Danielli, R., Ruani, G., Zamboni, R., and Taliani, C., Phys. Rev. Lett. 68, 919 (1992).Google Scholar
22. Soos, Z.G. and Galvão, D.S., J. Phys. Chem. (in press).Google Scholar