Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-17T23:19:57.786Z Has data issue: false hasContentIssue false

Determination of Traps in Poly(p-phenylene vinylene) Light Emitting Diodes by Chargebased Deep Level Transient Spectroscopy

Published online by Cambridge University Press:  01 February 2011

Olivier Gaudin
Affiliation:
Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
Richard B. Jackman
Affiliation:
Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
Thien-Phap Nguyen
Affiliation:
Laboratoire de Physique Cristalline, Institut des Matériaux Jean Rouxel, Université de Nantes, 2 rue de la Houssinière, 44 322 Nantes Cedex 03, France
Philippe Le Rendu
Affiliation:
Laboratoire de Physique Cristalline, Institut des Matériaux Jean Rouxel, Université de Nantes, 2 rue de la Houssinière, 44 322 Nantes Cedex 03, France
Get access

Abstract

Charge-based deep level transient spectroscopy (Q-DLTS) has been used to study the defect states that exist within poly(p-phenylene vinylene) (PPV), a semiconducting polymer with a band gap of about 2.4 eV. The technique allows the determination of activation energies, capture cross-sections and trap concentrations. In some circumstances, it is also possible to distinguish between minority and majority carrier traps. The structures investigated here consisted of ITO/PPV/MgAg light emitting diode (LED) devices. Two types of trapping centres were found. The first type has activation energies in the range 0.49 – 0.53 eV and capture cross-sections of the order of 10-16 – 10-18 cm2. It shows a Poole-Frenkel, field assisted-emission process. This level has been identified as a bulk acceptor-like majority carrier (i.e., hole) trap. The second type has activation energies in the range 0.40 – 0.42 eV and capture cross-sections of the order of 10-19 cm2. This level has been identified as a minority carrier (i.e., electron) trap. This second trap type is therefore expected to limit minority carrier injection into the PPV layer within the LED, and hence reduce electroluminescence under forward bias conditions.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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

1. Nguyen, T. P. Tran, V. H. and Massardier, V. J. Phys.: Condens. Matter 5, 6243 (1993)Google Scholar
2. Meier, M. Karg, S. Zuleeg, K. Brütting, W., and Schwoerer, M. J. Appl. Phys. 84, 87 (1998)Google Scholar
3. Onoda, M. Park, D. H. and Yoshino, K. J. Phys.: Condens. Matter 1, 113 (1989)Google Scholar
4. Scherbel, J. Nguyen, P. H. Paasch, G. Brütting, W., and Schwoerer, M. J. Appl. Phys. 83, 5045 (1998)Google Scholar
5. Campbell, A. J. Bradley, D. D. C. Werner, E. and Brütting, W., Synth. Met. 111-112, 273 (2000)Google Scholar
6. Lang, D. V. J. Appl. Phys. 45, 3023 (1974)Google Scholar
7. Farmer, J. W. Lamp, C. D. and Meese, J. M. Appl. Phys. Lett. 41, 1063 (1981)Google Scholar
8. Kirov, K. I. and Radev, K. B. phys. stat. sol. (a) 63, 711 (1981)Google Scholar
9. Rukovishnikov, A. I. Polyakov, V. I. Perov, P. I. Ignatov, B. G. Ermakova, O. N. and Aleksandrov, A. L., Instrum. Exp. Tech. 300, 1226 (1987)Google Scholar
10. Polyakov, V. I. Perov, P. I. Ermakova, M. G. Ermakov, M. G. Rukovishnikov, A. I. and Sergeev, V. I. Sov. Phys. Semicond. 23, 76 (1989)Google Scholar
11. Polyakov, V. I. Perov, P. I. Ermakov, M. G. and Ermakova, O. N. Mikroelektronika 20, 155 (1991)Google Scholar
12. Wessling, R. A. and Zimmermann, R. G. US Patent, 1968, 3, 401, 152.Google Scholar
13. Rukovishnikov, A. I. Polyakov, V. I. Perov, P. I. Ermakova, O. N. Ermakov, M. G. Ignatov, B. G., Shemet, A. V. and Aleksandrov, A. L. Instrum. Exp. Tech. 33, 1199 (1990)Google Scholar
14. Arora, B. M. Chakravarty, S. Subramanian, S. Polyakov, V. I. Ermakov, M. G. Ermakova, O. N., and Perov, P. I. J. Appl. Phys. 73, 1802 (1993)Google Scholar
15. Gaudin, O. Jackman, R. B. Nguyen, T. P. and Rendu, P. Le, J. Appl. Phys. 90, 4196 (2001)Google Scholar
16. Nguyen, T. P. Tran, V. H. Massardier, V. and Guyot, A. Synth. Met. 55-57, 235 (1993)Google Scholar
17. Kimerling, L. C. and Benton, J. L. Appl. Phys. Lett. 39, 410 (1981)Google Scholar
18. Lang, D. V. J. Appl. Phys. 45, 3014 (1974)Google Scholar
19. Simmons, J. G. Phys. Rev. 155, 657 (1967)Google Scholar
20. Simmons, J. G. J. Phys. D 4, 613 (1971)Google Scholar
21. Mooney, P. M. in Identification of Defects in Semiconductors, edited by Stavola, M. Semiconductors and Semimetals (Academic Press, San Diego, 1999), p. 93.Google Scholar