Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-24T07:34:47.408Z Has data issue: false hasContentIssue false

Multilayer Structures and Emissive Regions in Organic Thin-Film Electroluminescent Diodes

Published online by Cambridge University Press:  10 February 2011

E. Aminaka
Affiliation:
Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816, Japan
T. Tsutsui
Affiliation:
Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816, Japan
Get access

Abstract

The relationships between emission quantum efficiency and emissive regions in organic thin-film electroluminescent (EL) devices were studied. As an emissive layer (EML) and an electron transport layer (ETL) material, 9, 10-bis(4-diphenylaminostyryl)anthracene and 1,3- bis(4-tert-butylphenyl-1,3,4-oxadiazolyl)phenylene, respectively, were used. A zone doped with 2,4-bis(4-diethylamino-2-hydroxyphenyl)-1,3-dihydroxycycrobutenediylium dihydroxide was formed in an EML. The relationships between the emission intensities from the dopant and the positions of doped zones gave information on the emissive regions in each EL device. The emissive region in the single-layer (SL) device consisting only of an EML extended over the EML. That in the two-layer device (DL-E) in which an EML was combined with an ETL was located within 10 nm-wide region near the EML/ETL boundary. Moreover, the emission efficiency of the DL-E device was found to be about 20 times as high as that of the SL device. Therefore, it was found that the carrier recombination within the narrow region sufficiently apart from electrodes gave high emission efficiency.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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. Tsutsui, T. and Saito, S., in Intrinsically Conducting Polymers: An Emerging Technology, edited by M., Aldissi (Kluwer Academic Publishers, The Netherlands, 1993), p. 123.Google Scholar
2. Baigent, D. R., Greenham, N. C., Gruner, J., Marks, R. N., Friend, R. H., Moratti, S. C. and A.Holmes, B., Synth. Met. 67, 3 (1994).Google Scholar
3. Tang, C. W., VanSlyke, S. A. and Chen, C. H., J. Appi. Phys. 65,3610 (1989).Google Scholar
4. Adachi, C., Tsutsui, T. and Saito, S., Optoelectronics-Devices and Technologies 6, 25 (1991).Google Scholar
5. Northrop, D. C. and Simpson, O., Proc. R. Soc. London, Ser. A 234, 136 (1956).Google Scholar
6. Ohta, M., Sakon, Y., Takahashi, T. and Ohnuma, T., Polymer Preprints, Japan 40,3606 (1991) [in Japanese].Google Scholar
7. Stolka, M., Yanus, J. F. and Pai, D. M., J. Phys. Chem. 88,4707 (1984).Google Scholar
8. Hamada, Y., Adachi, C., Tsutsui, T. and Saito, S., Nippon Kagaku Kaishi (J. Chem. Soc. Jpn.) 1991, 1540 [in Japanese].Google Scholar
9. Kurczewska, H. and Bassler, H., J. Lumin. 15, 261 (1977).Google Scholar
10. Tsutsui, T., Aminaka, E., Hamada, Y., Adachi, C. and Saito, S., in Electroluminescent Materials, Devices, and Large-Screen Displays, edited by Conwell, E. M., Stolka, M. and Miller, M. R.,(Proc. SPIE 1910, San Jose, CA, 1993), p. 180.Google Scholar
11. Aminaka, E., Tsutsui, T. and Saito, S., Jpn. J. Appl. Phys. Part 1 33, 1061 (1994).Google Scholar