Letter | Published:

Highly efficient phosphorescent emission from organic electroluminescent devices

Nature volume 395, pages 151154 (10 September 1998) | Download Citation

Subjects

Abstract

The efficiency of electroluminescent organic light-emitting devices1,2 can be improved by the introduction3 of a fluorescent dye. Energy transfer from the host to the dye occurs via excitons, but only the singlet spin states induce fluorescent emission; these represent a small fraction (about 25%) of the total excited-state population (the remainder are triplet states). Phosphorescent dyes, however, offer a means of achieving improved light-emission efficiencies, as emission may result from both singlet and triplet states. Here we report high-efficiency (90%) energy transfer from both singlet and triplet states, in a host material doped with the phosphorescent dye 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II) (PtOEP). Our doped electroluminescent devices generate saturated red emission with peak external and internal quantum efficiencies of 4% and 23%, respectively. The luminescent efficiencies attainable with phosphorescent dyes may lead to new applications for organic materials. Moreover, our work establishes the utility of PtOEP as a probe of triplet behaviour and energy transfer in organic solid-state systems.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from $8.99

All prices are NET prices.

References

  1. 1.

    & US Patent No. 4539507 ((1985)).

  2. 2.

    Light emitting diodes based on conjugated polymers. Nature 347, 539–541 (1990).

  3. 3.

    , & Electroluminescence of doped organic thin films. J. Appl. Phys. 65, 3610–3616 (1989).

  4. 4.

    & Organic Multilayer-Dye Electroluminescent Diodes—Is There Any Difference with Polymer LED? (Kluwer Academic, Dordrecht, (1993)).

  5. 5.

    & Status of and prospects for organic electroluminescence. J. Mater. Res. 11, 3174–3187 (1996).

  6. 6.

    High-external-quantum-efficiency organic light-emitting devices. Opt. Lett. 22, 396–398 (1997).

  7. 7.

    Vacuum-deposited thin films of lanthanide complexes: spectral properties and applications in organic light-emitting devices.In SID 97 Digest(ed. Morreale, J.) 778–781 (Soc. for Information Display, Santa Ana, CA, (1997).

  8. 8.

    & Electroluminescence from triplet excited states of benzophenone. Appl. Phys. Lett. 69, 224–226 (1996).

  9. 9.

    & Controlling the response characteristics of luminescent porphyrin plastic film sensors for oxygen. Anal. Chem. 69, 4653–4659 (1997).

  10. 10.

    , , & Comparison of radiationless decay processes in osmium and platinum porphyrins. J. Am. Chem. Soc. 105, 4639–4645 (1983).

  11. 11.

    New oxygen sensors and their applications to biosensing. Sens. Actuators B 29, 213–218 (1995).

  12. 12.

    Modern Molecular Photochemistry (University Science Books, Mill Valley, CA, (1991)).

  13. 13.

    , , & Oxygen permeability of sol-gel coatings. Appl. Spectrosc. 46, 1266–1272 (1992).

  14. 14.

    , & Elucidation of the role of metal to ring charge-transfer states in the deactivation of photo-excited ruthenium porphyrin carbonyl complexes. Chem. Phys. Lett. 147, 235–240 (1988).

  15. 15.

    Bright, saturated, red-to-yellow organic light-emitting devices based on polarization-induced spectral shifts. Chem. Phys. Lett. 287, 455–460 (1998).

  16. 16.

    , , & Improved red dopants for organic electroluminescent devices. Macromol. Symp. 125, 49–58 (1997).

  17. 17.

    , , & Sharply directed emission in organic electroluminescent diodes with an optical-microcavity structure. Appl. Phys. Lett. 65, 1868–1870 (1994).

  18. 18.

    Bright red light emitting organic electroluminescent devices having a europium complex as an emitter. Appl. Phys. Lett. 65, 2124–2126 (1994).

  19. 19.

    Novel europium complexes for electroluminescent devices with sharp red emission. Jpn J. Appl. Phys. 34, 1883–1887 (1994).

  20. 20.

    , , & Photoluminescence efficiency and absorption of aluminum-tris-quinolate (Alq3) thin films. Chem. Phys. Lett. 249, 433–437 (1996).

Download references

Acknowledgements

We thank V. G. Kozlov for help with the transient measurements, and P. E. Burrows for discussions. This work was supported by Universal Display Corporation, DARPA, AFPSR and NSF.

Author information

Affiliations

  1. *Center for Photonics and Optoelectronic Materials, Department of Electrical Engineering and the Princeton Materials Institute, Princeton University, Princeton, New Jersey 08544, USA

    • M. A. Baldo
    • , D. F. O'Brien
    •  & S. R. Forrest
  2. †Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA

    • Y. You
    • , A. Shoustikov
    • , S. Sibley
    •  & M. E. Thompson
  3. ‡Permanent address: Department of Chemistry, Goucher College, Baltimore, Maryland 21204-2794, USA.

    • S. Sibley

Authors

  1. Search for M. A. Baldo in:

  2. Search for D. F. O'Brien in:

  3. Search for Y. You in:

  4. Search for A. Shoustikov in:

  5. Search for S. Sibley in:

  6. Search for M. E. Thompson in:

  7. Search for S. R. Forrest in:

Corresponding author

Correspondence to S. R. Forrest.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/25954

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.