Abstract
A new kind of rare earth (RE) complex Tb(o-MBA)3phen was synthesized and used as an emitting material in electroluminescence. The material was doped into poly(N-vinylcarbazole) (PVK) as the emitting layer, which was made by spin coating. Three kinds of devices were fabricated with the structures: (A) ITO/PVK:Tb(o-MBA)3phen/LiF/Al; (B) ITO/PVK:Tb(o-MBA)3phen/BCP/AlQ3/LiF/Al; (C) ITO/BCP/PVK: Tb(o-MBA)3phen/AlQ3/LiF/Al. Bright green emission could be obtained from device (A) and (C). The photoluminescence (PL) and electroluminescence (EL) mechanisms of this material had been investigated. Since there was an overlap between the PL spectrum of PVK and the excitation spectrum of the terbium complex, there should be a Förster energy transfer process between them. The excitation spectrum of PVK doped Tb(o-MBA)3phen system is similar with the excitation spectrum of PVK, yet it is different from that of Tb(o-MBA)3phen. So, the emission of Tb(o-MBA)3phen should partly come from the excitation of PVK while in the organic light-emitting diode (OLED), based on Tb(o-MBA)3phen, the emission mainly comes from the direct recombination of electron and hole. Bright green emission can be obtained from the optimized multi-layer device (C) and the highest EL brightness reached 180 cd/m2 at the voltage of 17 V.
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References
Tang C W, VanSlyke S A. Organic electroluminescent diodes. Applied Physics Letters, 1987, 51(12): 913–915
Tang C W, VanSlyke S A, Chen C H. Electroluminescence of doped organic thin films. Journal of Applied Physics, 1989, 65(9): 3610–3616
Burroughes J H, Bradley D D C, Brown A R, et al. Light-emitting diodes based on conjugated polymers. Nature, 1990, 347(6293): 539–541
Kido J, Nagai K, Okamoto Y, et al. Electroluminescence from polysilane film doped with europium complex. Chemistry Letters, 1991, 20(7): 1267–1270
Kido J, Hayase H, Hongawa K, et al. Bright red light-emitting organic electroluminescent devices having a europium complex as an emitter. Applied Physics Letters, 1994, 65(17): 2124–2126
Kido J, Ikeda W, Kimura M, et al. White-light-emitting organic electroluminescence device using lanthanide complexes. Japanese Journal of Applied Physics, 1996, 35(3): 394–396
Wang R F, Wang S P, Shi S K, et al. Crystal structure and properties of terbium o-methylbenzoate complex with 1,10-phenanthroline [Tb(o-CH3C6H4COO)3(C12H8N2)]2. Rare Metals, 2004, 23(2): 103–108
Duan N, Zhang X Q, Gao X, et al. Green electroluminescence generated from a new rare earth complex: Tb(asprin)3phen. Spectroscopy and Spectral Analysis, 2001, 21(3): 267–270 (in Chinese)
Liang C J, Li W L, Hong Z R, et al. Energy transfer process from polymer to rare earth complexes. Synthetic Metals, 1997, 91(1–3): 151–154
Zhang R J, Yang K Z, Yu A C, et al. Fluorescence lifetime and energy transfer of rare earth β-diketone complexes in organized molecular films. Thin Solid Films, 2000, 363(1–2): 275–278
Tao D L, Zhang T, Xu Y Z, et al. Study of energy transfer in luminescent materials containing lanthanide elements. Journal of the Chinese Rare Earth Society, 2001, 19(6): 543–547 (in Chinese)
Tao D L, Huang B G, Xu Y Z, et al. Energy transfer between electric polymer PVK and terbium complex and its transmission electronmicroscope (TME) study. Spectroscopy and Spectral Analysis, 2001, 21(6): 740–744 (in Chinese)
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Translated from Chinese Journal of Luminescence, 2007, 28(1): 39–43 [译自: 发光学报]
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Li, X., Deng, Z., Zhang, Y. et al. Emission mechanism in the terbium complex doped PVK system. Front. Optoelectron. China 1, 130–133 (2008). https://doi.org/10.1007/s12200-008-0010-8
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DOI: https://doi.org/10.1007/s12200-008-0010-8