Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T07:43:05.686Z Has data issue: false hasContentIssue false

Intrinsic Degradation in Alq3-Based OLEDs Probed by Deep-Level Optical Spectroscopy

Published online by Cambridge University Press:  31 January 2011

Yoshitaka Nakano*
Affiliation:
[email protected], Chubu University, Institute of Science and Technology Research, Kasugai, Japan
Get access

Abstract

We have successfully investigated degradation-induced variations in electronic band-gap states in the emissive region of the Alq3-based OLEDs by a deep-level optical spectroscopy technique. Through the intrinsic degradation, both deep-level traps and near-band-edge transitions in the Alq3 emissive zone are found to be red-shifted significantly towards their corresponding bulk levels of the Alq3 single layer. These variations in the interfacial electronic states are probably induced by the intrinsic degradation and indicate that initial molecular structures characteristic of the Alq3 emissive zone are transformed into the bulk-like relaxed ones through the degradation.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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 Tang, W. and VanSlyke, S. A., Appl. Phys. Lett. 51, 913 (1987).Google Scholar
2 Aziz, H., Popovic, Z. D., Hu, N.-X., Hor, A.-M., and Xu, G., Science 283, 1900 (1999).Google Scholar
3 Popovic, Z. D., Aziz, H., Hu, N.-X., Ioannidis, A., and Anjos, P. N. M. dos, J. Appl. Phys. 89, 4673 (2001).Google Scholar
4 Nakai, M., Fujii, H., Tsujioka, T., Hamada, Y., and Takahashi, H., Jpn. J. Appl. Phys. 41, 881 (2002).Google Scholar
5 Kondakov, D. Y., Sandifer, J. R., Tang, C. W., and Young, R. H., J. Appl. Phys. 93, 1108 (2003).Google Scholar
6 Féry, C., Racine, B., Vaufrey, D., Doyeux, H., and Cinà, S., Appl. Phys. Lett. 87, 213502 (2005).Google Scholar
7 Kondakov, D. Y., J. Appl. Phys. 97, 024503 (2005).Google Scholar
8 Kondakov, D. Y., Lenhart, W. C., and Nichols, W. F., J. Appl. Phys. 101, 024512 (2007).Google Scholar
9 Chantre, A., Vincent, G., and Bois, D., Phys. Rev. B 23, 5335 (1981).Google Scholar
10 Nakano, Y., Morikawa, T., Ohwaki, T., and Taga, Y., Appl. Phys. Lett. 86, 132104 (2005).Google Scholar
11 Nakano, Y., Noda, K., Fujikawa, H., Morikawa, T., Ohwaki, T., and Taga, Y., Appl. Phys. Lett. 88, 252104 (2006).Google Scholar
12 Nakano, Y., Noda, K., Fujikawa, H., Morikawa, T., and Ohwaki, T., Jpn. J. Appl. Phys. 46, 2636 (2007).Google Scholar
13 Nakano, Y., Noda, K., Fujikawa, H., and Morikawa, T., Jpn. J. Appl. Phys. 47, 464 (2008).Google Scholar
14 Noguchi, Y., Sato, N., Tanaka, Y., Nakayama, Y., and Ishii, H., Appl. Phys. Lett. 92, 203306 (2008).Google Scholar
15 Yamada, T., Zou, D., Jeong, H., Akaki, Y., and Tsutsui, T., Synth. Met. 111112, 237 (2000).Google Scholar
16 Silvestre, G. C. M., Johnson, M. T., Giraldo, A., and Shannon, J. M., Appl. Phys. Lett. 78, 1619 (2001).Google Scholar