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Recycling of Organic Materials Using Purification by Recrystallization for Solution-Processed OLEDs  

Lee, Jin-Hwan (School of Electrical & Electronic & Communication Engineering, Korea University of Technology and Education)
Hong, Ki-Young (School of Electrical & Electronic & Communication Engineering, Korea University of Technology and Education)
Shin, Dong-Kyun (School of Electrical & Electronic & Communication Engineering, Korea University of Technology and Education)
Lee, Jin-Young (School of Electrical & Electronic & Communication Engineering, Korea University of Technology and Education)
Park, Jong-Woon (School of Electrical & Electronic & Communication Engineering, Korea University of Technology and Education)
Seo, Hwa-Il (School of Electrical & Electronic & Communication Engineering, Korea University of Technology and Education)
Seo, Yu Seok (Advanced Technology Research Team, YOULCHON CHEMICAL, CO., LTD.)
Publication Information
Journal of the Semiconductor & Display Technology / v.15, no.1, 2016 , pp. 65-69 More about this Journal
Abstract
We have investigated the possibility of recycling of an organic material that is wasted during thermal evaporation. To this end, we have collected a wasted organic material (N,N'-diphenly-N,N'-bis(1,1'-biphenyl)-4,4'-diamine(NPB)) from a vacuum chamber, purified it by recrystallization, and fabricated bilayer organic light-emitting diodes (OLEDs) with the recycled NPB. It is found that the surface roughness of thin films coated with the purified NPB is much enhanced. OLEDs fabricated by thermal evaporation of the purified NPB show lower device efficiency than OLEDs with the original NPB. However, the power efficiency of OLED fabricated by spin coating of the purified NPB is comparable with that of OLED with the original NPB. Therefore, such a recycling method by recrystallization would be more suitable for solution-processed OLEDs.
Keywords
OLED; recycling; recrystallization; purification; solution process;
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1 L. Duan, L. Hou, T.-W. Lee, J. Qiao, D. Zhang, G. Dong, L. Wang and Y. Qiu, "Solution processable small molecules for organic light-emitting diodes," J. of Mater. Chem., vol. 20, pp. 6392-6407, 2010.   DOI
2 M. S. Weaver, R. C. Kwong, V. A. Adamovich, M. Hack and J. J. Brown, "Recent Advances in Phosphorescent OLEDs for Small and Large Area Displays Sizes,"'Proceedings of the Twenty-Fifth International Display Research Conference - Euro Display', SID, pp. 188-191, 2005.
3 B. W. D'Andrade, J. Esler, C. Lin, V. Adamovich, S. Xia, M. S. Weaver, R. Kwong and J. J. Brown, "Realizing white phosphorescent 100lm/W OLED efficacy," 'Organic Light Emitting Materials and Devices Xii', SPIE, vol. 7051, pp. 510-510, 2008.
4 S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lussem and K. Leo, "White organic lightemitting diodes with fluorescent tube efficiency," Nature, vol. 459, pp. 234-238, 2009.   DOI
5 Z. Q. Jiang, Y. H. Chen, C. Fan, C. L. Yang, Q. Wang, Y. T. Tao, Z. Q. Zhang, J. G. Qin and D. G. Ma, "Bridged triphenylamines as novel host materials for highly efficient blue and green phosphorescent OLEDs,"'ChemCommun', pp. 3398-3400, 2009.
6 Y. T. Tao, Q. Wang, C. L. Yang, Q. Wang, Z. Q. Zhang, T. T. Zou, J. G. Qin and D. G. Ma, "A simple carbazole/oxadiazole hybrid molecule: An excellent bipolar host for green and red phosphorescent OLEDs," Angew. Chem. Int. Ed., vol. 47(42), pp. 8104-8107, 2008.   DOI
7 H. Kim, Y. Byun, R. R. Das, B. K. Choi and P. S. Ahn, "Small molecule based and solution processed highly efficient red electrophosphorescent organic light emitting devices," Appl. Phys. Lett., vol. 91, pp. 093512, 2007.   DOI
8 C. Hosokawa, H. Higashi and T. Kusumoto, "Novel structure of organic electroluminescence cells with conjugated oligomers," Appl. Phys. Lett., vol. 62, pp. 3238-3240, 1993.   DOI
9 H. A. Neidig, "Purifying Acetanilide by Recrystallization," 'Laboratory Handbook for General Chemistry', pp. 31-39, 2004.
10 N. S. Cho, "Current Status of OLED Technology and Market," Poly. Sci. and Technol., vol. 24(2), pp. 126- 134, 2013.