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Influence of Electrode Modification by Ar+ Ion Beam Upon Passivation and Electrical Characteristics in Organic Light-Emitting Diodes

Published online by Cambridge University Press:  03 March 2011

Soon Moon Jeong
Affiliation:
Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Korea
Won Hoi Koo
Affiliation:
Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Korea
Sang Hun Choi
Affiliation:
Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Korea
Sung Jin Jo
Affiliation:
Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Korea
Hong Koo Baik*
Affiliation:
Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Korea
Se-Jong Lee
Affiliation:
Department of Materials Engineering, Kyungsung University, Busan 608-736, Korea
Kie Moon Song
Affiliation:
Department of Applied Physics, Konkuk University, Chungju 380-701, Korea
*
a)Address all correspondence to this author. e-mail: thinfilm@yonsei.ac.kr
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Abstract

Ion-beam-assisted deposition (IBAD) was used for cathode preparation in organic light-emitting diodes to fabricate dense electrode. Dark spot growth rate was decreased by employing the IBAD process due to a highly packed aluminum structure inhibiting the permeation of H2O and O2. However, undesirable leakage current was generated because energetic particles of Al assisted by Ar+ ion may damage the organic material resulting in reduction of contact resistance. The decrease of contact resistance in the IBAD device may be caused by large contact area, increase of density of states, and Li diffusion to phenyl-substituted poly-p-phenylene vinylene.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1Tang, C.W. and VanSlyke, S.A.: Organic electroluminescent diodes. Appl. Phys. Lett. 51, 913 (1987).Google Scholar
2Burroughes, J.H., Bradley, D.D.C., Brown, A.R., Marks, R.N., Mackay, K., Friend, R.H., Burn, P.L. and Holmes, A.B.: Light-emitting diodes based on conjugated polymers. Nature 347, 539 (1990).Google Scholar
3Rothberg, L.J. and Lovinger, A.J.: Status of and prospects for organic electroluminescence. J. Mater. Res. 11, 3174 (1996).Google Scholar
4Burrows, P.E., Bulovic, V., Forrest, S.R., Sapochak, L.S., McCarty, D.M. and Thompson, M.E.: Reliability and degradation of organic light-emitting devices. Appl. Phys. Lett. 65, 2922 (1994).Google Scholar
5Vimrova, V., Nespurek, S., Kuzel, R. and Schnabel, W.: Electrode-limited photoinjection at metal/polymer interface. Synth. Met. 67, 103 (1994).Google Scholar
6McElvain, J., Antoniadis, H., Hueschen, M.R., Miller, J.N., Roitman, D.M., Sheats, J.R. and Moon, R.L.: Formation and growth of black spots in organic light-emitting diodes. J. Appl. Phys. 80, 6002 (1996).Google Scholar
7Do, L.M., Oyamada, M., Koike, A., Han, E.M., Yamamoto, N. and Fujira, M.: Morphological change in the degradation of Al electrode surfaces of electroluminescent devices by fluorescence microscopy and AFM. Thin Solid Films 273, 209 (1996).CrossRefGoogle Scholar
8Savvateev, V.N., Yakimov, A.V., Davidov, D., Pogreb, R.M., Neumann, R. and Avny, Y.: Degradation of nonencapsulated polymer-based light-emitting diodes: Noise and morphology. Appl. Phys. Lett. 71, 3344 (1997).Google Scholar
9Liao, L.S., Hung, L.S., Chan, W.C., Ding, X.M., Sham, T.K., Bellow, I., Lee, C.S. and Lee, S.T.: Ion-beam-induced surface damages on tris-(8-hydroxyquinoline) aluminum. Appl. Phys. Lett. 75, 1619 (1999).Google Scholar
10Suzuki, H. and Hikita, M.: Organic light-emitting diodes with radio frequency sputter-deposited electron injecting electrodes. Appl. Phys. Lett. 68, 2276 (1996).Google Scholar
11Gu, G., Bulovic, V., Burrows, P.E., Forrest, S.R. and Thompson, M.E.: Transparent organic light-emitting devices. Appl. Phys. Lett. 68, 2606 (1996).Google Scholar
12Hung, L.S., Liao, L.S., Lee, C.S. and Lee, S.T.: Sputter deposition of cathodes in organic light emitting diodes. J. Appl. Phys. 86, 4607 (1999).Google Scholar
13Parker, I.D.: Carrier tunneling and device characteristics in polymer light-emitting diodes. J. Appl. Phys. 75, 1656 (1994).Google Scholar
14Blom, P.W.M., de Jong, M.J.M. and Vleggaar, J.J.M.: Electron and hole transport in poly(p-phenylene vinylene) devices. Appl. Phys. Lett. 68, 3308 (1996).CrossRefGoogle Scholar
15Campbell, A.J., Bradley, D.D.C. and Lidzey, D.G.: Space-charge limited conduction with traps in poly(phenylene vinylene) light emitting diodes. J. Appl. Phys. 82, 6326 (1997).Google Scholar
16Shen, J. and Yang, J.: Physical mechanisms in double-carrier trap-charge limited transport processes in organic electroluminescent devices: A numerical study. J. Appl. Phys. 83, 7706 (1998).Google Scholar
17Antoniadis, H., Abkowitz, M.A. and Hsieh, B.R.: Carrier deep-trapping mobility-lifetime products in poly(p-phenylene vinylene). Appl. Phys. Lett. 65, 2030 (1994).Google Scholar
18Cuomo, J.J., Rossnagel, S.M. and Kaufman, H.R. Handbook of Ion Beam Processing Technology-Principles, Deposition, Film Modification and Synthesis, (Noyes Publications, Park Ridge, NJ, 1989), p. 263.Google Scholar
19Henry, B.M., Dinelli, F., Zhao, K-Y., Grovenor, C.R.M., Kolosov, O.V., Briggs, G.A.D., Roberts, A.P., Kumar, R.S. and Howson, R.P.: A microstructural study of transparent metal oxide gas barrier films. Thin Solid Films 355, 500 (1999).Google Scholar
20Tropsha, Y.G. and Harvey, N.G.: Activated rate theory treatment of oxygen and water transport through silicon oxide/poly(ethylene terephthalate) composite barrier structures. J. Phys. Chem. B. 101, 2259 (1997).CrossRefGoogle Scholar
21Erlat, A.G., Spontak, R.J., Clarke, R.P., Robinson, T.C., Haaland, P.D., Tropsha, Y., Harvey, N.G. and Vogler, E.A.: SiOx gas barrier coatings on polymer substrates: Morphology and gas transport considerations. J. Phys. Chem. B 103, 6047 (1999).Google Scholar
22Sobrinho, A.S. da Silva, Czeremuszkin, G., Latreche, M. and Wertheimer, M.R.: Defect-permeation correlation for ultrathin transparent barrier coatings on polymers. J. Vac. Sci. Technol. A 18, 149 (2000).Google Scholar
23Henry, B.M., Dinelli, F., Zhao, K-Y., Grovenor, C.R.M., Kolosov, O.V., Briggs, G.A.D., Roberts, A.P., Kumar, R.S. and Howson, : A microstructural study of transparent metal oxide gas barrier films. Thin Solid Films. 335356.Google Scholar
24Roberts, A.P., Henry, B.M., Sutton, A.P., Grovenor, C.R.M., Briggs, G.A.D., Miyamoto, T., Kano, M., Tsukahara, Y. and Yanaka, M.: Gas permeation in silicon-oxide/polymer (SiOx/PET) barrier films: Role of the oxide lattice, nano-defects and macro-defects. J. Membr. Sci. 208, 75 (2002).Google Scholar
25Kwak, J.S., Baik, H.K., Kim, J.H. and Lee, S.M.: Suppression of silicide formation in Ta/Si system by ion-beam-assisted deposition. Appl. Phys. Lett. 71, 2451 (1997).Google Scholar
26Burrows, P.E. and Forrest, S.R.: Electroluminescence from trap-limited current transport in vacuum-deposited organic light-emitting devices. Appl. Phys. Lett. 64, 2285 (1994).Google Scholar
27Burrows, P.E., Shen, Z., Bulovic, V., McCarty, D.M. and Forrest, S.R.: Relationship between electroluminescence and current transport in organic heterojunction light-emitting devices. J. Appl. Phys. 79, 7991 (1996).Google Scholar
28Meier, M., Karg, S. and Riess, W.: Light-emitting diodes based on poly-p-phenylene-vinylene: II. Impedance spectroscopy. J. Appl. Phys. 82, 1961 (1997).Google Scholar
29Aziz, H. and Xu, G.: Electric-field-induced degradation of poly(p-phenylenevinylene) electroluminescent devices. J. Phys. Chem. 101, 4009 (1997).Google Scholar
30Parthasarathy, G., Burrows, P.E., Khalfin, V., Kozlov, V.G. and Forrest, S.R.: A metal-free cathode for organic semiconductor devices. Appl. Phys. Lett. 72, 2138 (1998).Google Scholar
31Bulovic, V., Tian, P., Burrows, P.E., Gokhale, M.R. and Forrest, S.R.: A surface-emitting vacuum-deposited organic light emitting device. Appl. Phys. Lett. 70, 2954 (1997).Google Scholar
32Forrest, S.R., Leu, L.Y., So, F.F. and Yoon, W.Y.: Optical and electrical properties of isotype crystalline molecular organic heterojunctions. J. Appl. Phys. 66, 5908 (1989).Google Scholar
33Rajagopal, A., Wu, C.I. and Kahn, A.: Energy level offset at organic semiconductor heterojunctions. J. Appl. Phys. 83, 2649 (1998).Google Scholar
34Parthasarathy, G., Adachi, C., Burrows, P.E. and Forrest, S.R.: High-efficiency transparent organic light-emitting devices. Appl. Phys. Lett. 76, 2128 (2000).Google Scholar
35Haskal, E.I., Curioni, A., Seidler, P.F. and Andreoni, W.: Transparent organic light-emitting devices. Appl. Phys. Lett. 68, 2606 (1997).Google Scholar
36Kido, J. and Matsumoto, T.: Bright organic electroluminescent devices having a metal-doped electron-injecting layer. Appl. Phys. Lett. 73, 2866 (1998).Google Scholar