Browse > Article
http://dx.doi.org/10.3740/MRSK.2008.18.4.199

Fabrication and Characterization of High Efficiency Green PhOLEDs with [TCTA-TAZ] : Ir(ppy)3 Double Emission Layers  

Shin, Sang-Baie (Department of Electronics Engineering, Dankook University)
Shin, Hyun-Kwan (Department of Electronics Engineering, Dankook University)
Kim, Won-Ki (Department of Electronics Engineering, Dankook University)
Jang, Ji-Geun (Department of Electronics Engineering, Dankook University)
Publication Information
Korean Journal of Materials Research / v.18, no.4, 2008 , pp. 199-203 More about this Journal
Abstract
High-efficiency phosphorescent organic light emitting diodes using TCTA-TAZ as a double host and $Ir(ppy)_3$ as a dopant were fabricated and their electro-luminescence properties were evaluated. The fabricated devices have the multi-layered organic structure of 2-TNATA/NPB/(TCTA-TAZ) : $Ir(ppy)_3$/BCP/SFC137 between an anode of ITO and a cathode of LiF/AL. In the device structure, 2-TNATA[4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] and NPB[N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] were used as a hole injection layer and a hole transport layer, respectively. BCP [2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline] was introduced as a hole blocking layer and an electron transport layer, respectively. TCTA [4,4',4"-tris(N-carbazolyl)-triphenylamine] and TAZ [3-phenyl-4-(1-naphthyl)-5-phenyl-1,2,4-triazole] were sequentially deposited, forming a double host doped with $Ir(ppy)_3$ in the [TCTA-TAZ] : $Ir(ppy)_3$ region. Among devices with different thickness combinations of TCTA ($50\;{\AA}-200\;{\AA}$) and TAZ ($100\;{\AA}-250\;{\AA}$) within the confines of the total host thickness of $300\;{\AA}$ and an $Ir(ppy)_3$-doping concentration of 7%, the best electroluminescence characteristics were obtained in a device with $100\;{\AA}$-think TCTA and $200\;{\AA}$-thick TAZ. The $Ir(ppy)_3$ concentration in the doping range of 4%-10% in devices with an emissive layer of [TCTA ($100\;{\AA}$)-TAZ ($200\;{\AA}$)] : $Ir(ppy)_3$ gave rise to little difference in the luminance and current efficiency.
Keywords
PhOLED; luminance; current efficiency; TCTA; TAZ;
Citations & Related Records

Times Cited By SCOPUS : 1
연도 인용수 순위
1 J. G. Jang, Organic Electronics, p.314, Cheongmoongak, Gyonggi, Korea, (2006)
2 R. Farchioni and G. Gross, Organic Electronic Materials, p. 428, Springer Series in Materials Science, Berlin, (2001)
3 M. Toerker, M. Eritt, Ch. May, J. Amelung, C. Luber, R. Hermann, Ch. Zschippang, Y. Tomita and K. Leo, Proc. SID International Symposium, 37(2), 1471 (2006)
4 B. J. Chen, X.W. Sun and K. R. Sarma, Mat. Sci. Eng. B., 139, 192 (2007)   DOI   ScienceOn
5 K. Goushi, Y. Kawamura, H. Sasabem and C. Adachi, Jpn. J. of. Appl. Phys. Lett., 43, L937 (2004)   DOI   ScienceOn
6 H. Kajii, Y. Sekimoto, Y. Hino and Y. Ohmori, Thin Solid Films, 516, 2272 (2008)   DOI   ScienceOn
7 J. Sun, X. Zhu, X. Yu, M. Wong and H. S. Kwok, SID 07 DIGEST, 826 (2007)
8 M. A. Baldo, D. F. O'Brien, Y. You, A. Shoustikov, S. Sibley, M. R. Thomson and S. R. Forrest, Nature, 395, 151 (1998)   DOI   ScienceOn
9 S. H. Kim, J. S. Jang, K. S Yook, J. Y. Lee, M. S. Gong, S. Ryu, G. K. Chang and H. J. Chang, J. of Appl. Phys. Lett., 103, 054502 (2008)
10 T. Zheng and W. C. H. Choy, J. Phys. D: Appl. Phys., 41, 055103 (2008)   DOI   ScienceOn
11 M. B. Khalifa, D. Vaufrey and J. Tardy, Organic Electronics, 5, 187 (2004)   DOI   ScienceOn
12 J. Kido, W. Ikeda, M. Kimura and K. Nagai, Jpn. J. Appl. Phys., 35, L394 (1996)   DOI   ScienceOn
13 C. W. Tang and S. A. VanSlyke, J. of Appl. Phys. Lett., 51, 913 (1987)   DOI
14 Z. H. Kafafi, Organic Electroluminescence, p. 274-286, Taylor & Francis, New York, (2005)
15 C. Adachi, M. A. Baldo, M. E. Thompson, and S. R. Forrest, J. of Appl. Physics, 90, 5048 (2001)   DOI   ScienceOn