1997 Fiscal Year Final Research Report Summary
White-Light-Emitting Organic Electroluminescent Devices
| Project/Area Number |
08455003
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | Yamagata University |
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Principal Investigator |
KIDO Junji Yamagata University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (50214838)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Electroluminescence / White light / Oxadiazole / Poly (N-vinylcarbazole) / Polyaniline / Copolymer |
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| Research Abstract |
In this research project, we have first investigated polymer single layr EL devices. Three systems, including copolymer, polymer blend, and dye-dispersion were investigated. N-vinylcarbazole and 1,3,4-oxadiazole derivative were used as a holetransporting unit and electron-transporting unit, respectively. In the dye-dispersion system, poly (N-vinylcarbazole) (PVK) was molecularly dispersed with a low molecular weight oxadiazole derivative. With an appropriate concentration of the oxadiazole (approximately 30wt%), the single layr device exhibited bright emission. Similarly, the copolymer system, which is a random copolymer of N-vinylcarbazole and vinyloxadiazole, showed reasonably high device efficiency. In contrast, the polymer blend system, containing the homopolymers of N-vinylcarbazole and vinyloxadiazole, resulted in the poor film-forming property.
We also investigated polyaniline as a buffer layr for the hole injection from ITO electrode to the hole transport layr. When the hole-transport layr is PVK,the annealing of the PVK layr after spincast improved device efficiency. This is attributed to the increase in the contact surface area between polyaniline layr and the PVK layr.
The above results are quite useful for the development of efficient white-light-emitting EL devices.
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