A light-emitting device based on a CdTe nanocrystal/polyaniline composite

Abstract

CdTe nanocrystal/polyaniline composite films as well as films of closely packed CdTe nanocrystals were used to fabricate light-emitting devices with low turn-on voltages [∽2.5 V for a device with a Mg cathode and an indium tin oxide (ITO) anode]. In principle, the emitted colour is tunable from green to red, depending on the size of the nanocrystals. The use of the particle loaded polyaniline film as the light-emitting layer results in a considerable enhancement of the quantum efficiency in comparison with the polymer-free device with closely packed CdTe nanocrystals. The light-emitting devices are found to work more efficiently in a pulsed mode than under continuous operation.

References

1. V. L. Colvin, M. C. Schlamp and A. P. Alivisatos, Nature, 1994, 370, 354.
2. B. O. Dabbousi, M. G. Bawendi, O. Onitsuka and M. F. Rubner, Appl. Phys. Lett., 1995, 66, 1316.
3. Y. Yang, S. Xue, S. Liu, J. Huang and J. Shen, Appl. Phys. Lett., 1996, 69, 377.
4. M. V. Artemyev, V. Sperling and U. Woggon, J. Appl. Phys., 1997, 81, 6975.
5. M. Gao, B. Richter and S. Kirstein, Adv. Mater., 1997, 9, 802.
6. M. Gao, B. Richter, S. Kirstein and H. Möhwald, J. Phys. Chem. B, 1998, 102, 4096.
7. H. Mattoussi, L. H. Radzilowski, B. O. Dabbousi, E. L. Thomas, M. G. Bawendi and M. F. Rubner, J. Appl. Phys., 1998, 83, 7965.
8. A. L. Rogach, L. Katsikas, A. Kornowski, D. Su, A. Eychmüller and H. Weller, Ber. Bunsenges. Phys. Chem., 1997, 101, 1668.
9. M. Gao, S. Kirstein, H. Möhwald, A. L. Rogach, A. Kornowski, A. Eychmüller and H. Weller, J. Phys. Chem. B, 1998, 102, 8360.
10. A. G. MacDiarmid and A. J. Epstein, Mater. Res. Soc. Symp. Proc., 1994, 328, 133.
11. S.-A. Chen, K.-R. Chuang, C.-I. Chao and H.-T. Lee, Synth. Met., 1996, 82, 207.
12. A. J. Heeger, I. D. Parker and Y. Yang, Synth. Met., 1994, 67, 23.
13. S. Karg, J. C. Scott, J. R. Salem and M. Angelopoulos, Synth. Met., 1996, 80, 111.
14. J.-C. LaCroix and A. F. Diaz, J. Electrochem. Soc., 1988, 135, 1457.
15. G. Gustafsson, G. M. Treacy, Y. Gao, F. Klavetter, N. Colaneri and A. J. Heeger, Synth. Methods, 1993, 55–57, 4123.
16. N. P. Gaponik, D. V. Talapin, A. L. Rogach and A. Eychmüller, in preparation.