Electrophosphorescent polymer light-emitting

A Nakamura, T Tada, M Mizukami, and S Yagyu, Efficient electrophosphorescent polymer light-emitting devices using a Cs/Al cathode, Appl. Phys. Lett., 84 130-132, 2004. 

TF Guo, SC Chang, Y Yang, RC Kwong, and ME Thompson, Highly efficient electrophosphorescent polymer light-emitting devices, Org. Electron., 1 15-20, 2000. 

F.C. Chen, G. He, and Y. Yang, Triple exciton confinement in electrophosphorescent polymer light-emitting diodes, Appl. Phys. Lett., 82 1006-1008, 2003. 

PA Lane, LC Palilis, DF O Brien, C Giebeler, AJ Cadby, DG Lidzey, AJ Campbell, W Blau, and DDC Bradley, Origin of electrophosphorescence from a doped polymer light emitting diode, Phys. Rev. B, 63 235206, 2001. 

W Zhu, C Liu, L Su, W Yang, M Yuan, and Y Cao, Synthesis of new iridium complexes and their electrophosphorescent properties in polymer light-emitting diodes, J. Mater. Chem., 13 50-55, 2003. 

Polymer light-emitting devices (PLEDs) have attracted considerable interest because of their potential use in portable electronic devices. PLEDs have improved the performance of devices by increasing the device stability and efficiency. Chang and coworkers fabricated an efficient PLED using [Ir(acac)(dbq)2] as the phosphorescent dopant of a pvk matrix layer and bbpo as the electron transport material. Trapping of charge carriers at the [Ir(acac)(dbq)2] dopant sites dominates the EL of the device. This is the first PLED that emits red electrophosphorescence centered at 610 nm, exclusively from the dopant and an EL efficiency of 8.5 cdA (luminance 1287 cdm ) biased at 14.5 mAcm . ... 

Zhu MX, Wu ZL, Jiang CY, Liu J, Li JR, Xing KQ, et al. Highly efficient electrophosphorescence from a grafted biscyclometalated iridium complex with triarylamine unit in polymer light-emitting devices. Chin Phys Lett 2005 22(7) 1793-6. 

There is no reason why the same principle cannot be applied for light-emitting polymers as host materials to pave a way to high-efficiency solution-processible LEDs. In fact, polymer-based electrophosphorescent LEDs (PPLEDs) based on polymer fluorescent hosts and lanthanide organic complexes have been reported only a year after the phosphorescent OLED was reported [8]. In spite of a relatively limited research activity in PPLEDs, as compared with phosphorescent OLEDs, it is hoped that 100% internal quantum efficiency can also be achieved for polymer LEDs. In this chapter, we will give a brief description of the photophysics beyond the operation of electrophosphorescent devices, followed by the examples of the materials, devices, and processes, experimentally studied in the field till the beginning of 2005. 

Y Kawamura, S Yanagida, and SR Forrest, Energy transfer in polymer electrophosphorescent light emitting devices with single and multiple doped luminescent layers, J. Appl. Phys., 92 87-93,... 

X Gong, JC Ostrowski, D Moses, GC Bazan, and AJ Heeger, High-performance polymer-based electrophosphorescent light-emitting diodes, J. Polym. Sci. B Polym. Phys., 41 2691-2705,... 

Tanaka, M. Suzuki, and S. Tokito. White fight emission from polymer electrophosphorescent light-emitting devices doped with iridium complexes. Jpn. J. Appl. Phys., Part 1,42(5A) 2737-2740, May 2003. 

FIGURE 2.6 (A) Chemical structures of white light-emitting polymers 93-97. (B) Chemical structures of electrophosphorescent polymers 98-103. 

Lee CL, Das RR, Kim JJ. Polymer-based blue electrophosphorescent light-emitting diodes using a bisorthometalated Ir(III) complex as the triplet emitter. Chem Mater 2004 16(23) 4642-6. 

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