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981.
Wen‐Fen Su Ruei‐Tang Chen Yun Chen 《Journal of polymer science. Part A, Polymer chemistry》2011,49(2):352-360
This article reports the synthesis and characterization of a novel thermally crosslinkable hole‐transporting poly (fluorene‐co‐triphenylamine) (PFO‐TPA) by Suzuki coupling reaction, followed with its application in the fabrication of multilayer light‐emitting diodes by wet processes. The thermal, photophysical, and electrochemical properties of PFO‐TPA were investigated by differential scanning calorimeter, thermogravimetric analysis, optical spectroscopy, and cyclic voltammetry, respectively. Thermally crosslinked PFO‐TPA, through pendant styryl groups, demonstrates excellent thermal stability (Td > 400 °C, Tg = 152 °C), solvent resistance, and film homogeneity. Its highest occupied molecular orbital level (?5.30 eV) lies between those of PEDOT:PSS (?5.0 ~ ?5.2 eV) and poly(9,9‐dioctylfluorene) (PFO: ?5.70 eV), forming a stepwise energy ladder to facilitate hole injection. Multilayer device with crosslinked PFO‐TPA as hole‐injection layer (HIL) (ITO/PEDOT:PSS/HIL/PFO/LiF/Ca/Al) was readily fabricated by successive spin‐coating processes, its maximum luminance efficiency (3.16 cd/A) were about six times higher than those without PFO‐TPA layer (0.50 cd/A). The result of hole‐only device also confirmed hole‐injection and hole‐transport abilities of crosslinked PFO‐TPA layer. Consequently, the device performance enhancement is attributed to more balanced charges injection in the presence of crosslinked PFO‐TPA layer. The thermally crosslinkable PFO‐TPA is a promising material for the fabrication of efficient multilayer polymer light‐emitting diodes because it is not only a hole‐transporting polymer but also thermally crosslinkable. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
982.
Mui Siang Soh Sonsoles Amor Garcia Santamaria Evan Laurence Williams Marta Pérez‐Morales Henk J. Bolink Alan Sellinger 《Journal of Polymer Science.Polymer Physics》2011,49(7):531-539
A new class of solution processable dendrimers based on cyclic phosphazene (CP) cores have been prepared and used as host materials for blue and green organic light emitting diodes (OLEDs). The dendrimers are prepared in high yield from minimal step reactions, are soluble in common solvents for solution processing, are amorphous, and have excellent thermal properties necessary for application in OLEDs. OLED efficiencies of 10.3 cd/A (4.2 lm/W) and 35.3 cd/A (33.5 lm/W) were achieved using commercially available FIrpic and Ir(mppy)3 as blue and green phosphorescent emitters, respectively. These efficiencies were 2× higher than control devices prepared using poly(N‐vinylcarbazole), the most commonly used host material in solution processed phosphorescent OLEDs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
983.
Lin Ke Shuang Fang Lim Soo Jin Chua 《Journal of Polymer Science.Polymer Physics》2001,39(14):1697-1703
Dark spot growth rate tracing experiments performed on an organic light‐emitting device show that moisture entering into the device is relatively properly fitted by Fick's diffusion equation in the substrate/indium tin oxide (ITO)/hole transport layer (HTL)/silver (Ag) structure. It is believed that the moisture is dissolved into the polymer layer, which results in a decrease in the diffusion coefficient in the device with the substrate/ITO/HTL/electroluminescent (EL) polymer/Ag structure. The diffusion and chemical reaction occurring in the cathode layer further decreases the diffusion coefficient in the device with the substrate/ITO/HTL/EL polymer/calcium/Ag structure. Useful parameters, such as diffusion and solubility constants, describing possible mechanisms happening during dark spot growth on organic light‐emitting diode devices are extracted. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1697–1703, 2001 相似文献
984.
We present a revised assignment of the Raman active fundamental vibrations of TCNE which utilizes new information obtained from Raman studies of electron donor/acceptor complexes of TCNE. This new assignment is consistent with and supported by all available evidence from previous studies. 相似文献
985.
在pH 2.2 BR缓冲介质中, 磷钨杂多酸(PTA)与格拉司琼(GSN)相互作用形成离子缔合物, 不仅引起吸收光谱的变化, 还导致共振散射光谱(RLS)的显著增强并产生新的RLS光谱, 最大RLS峰位于333 nm附近, 其RLS增强程度与格拉司琼浓度成线性关系, 检出限和线性范围分别为12 ng/mL和0.04~3.0 μg/mL。文中研究了反应产物的吸收和RLS光谱特征, 优化反应条件的影响, 据此发展了以磷钨杂多酸为光谱探针的灵敏、简便、快速测定格拉司琼的新方法。将方法用于血清中格拉司琼含量的快速定, 结果满意。讨论了离子缔合反应和RLS增强机理。 相似文献
986.
Muhammad Akhyar Farrukh Noureen Siraj Iftikhar Imam Naqvi 《Journal of Saudi Chemical Society》2010,14(2):209-212
Iron has been determined in apple and vegetables spectrophotometrically, by complexing it with xylenol orange. 1:1 complex formed in a highly acidic medium is measured for its absorbance at its λmax of 585 nm. The results have been compared by employing atomic absorption technique. Apples and vegetable samples were collected from local markets of Pakistan. Statistical manipulations, t-test and F-test, were performed and it was found that the results from the two techniques have an excellent agreement. 相似文献
987.
We report dynamic light scattering and small angle neutron scattering studies of the pressure-induced structural transition
of nonionic micelles of surfactant polyoxyethylene 10 lauryl ether (C12E10) in the pressure range 0 to 2000 bar. Measurements
have been performed on 1 wt% C12E10 in aqueous solution with and without the addition of KF. Micelles undergo sphere to lamellar
structural transitions as the pressure is increased. On addition of KF, rod-like micelles exist at ambient pressure, which
results in rod-like to lamellar structural transition at a much lower pressure in the presence of KF. Micellar structural
transitions have been observed to be reversible.
相似文献
988.
B. Witzel N.A. Papadogiannis D. Charalambidis 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,12(1):21-25
A new device for charged particle coincidence experiments in strong-field, short pulse laser-atom/molecule interactions is
presented. The device consists of a single time of flight spectrometer, common for both positive and negative charge detection.
Experimental parameters required for the use of the device in the high intensity regime are discussed. A demonstration of
electron-ion coincidence measurements in the interaction of Xe atoms with 60 fs laser pulses at 800 nm and an intensity of
W/cm2 is reported.
Received 22 November 1999 相似文献
989.
The stationary random responses of nonlinear shear-type Multi-Degrees-of-Freedom (MDOF) hysteretic system are analyzed by
using the Pseudo Excitation Method (PEM) combined with the Equivalent Linearization Method (ELM). The solution of the equivalent
linear system is obtained by iteratively solving complex algebraic equations instead of the Lyapunov equations. The efficiency
of this method is much higher for practical engineering systems with many degrees-of-freedom.
Supported by NNSFC (Project No. 19772009), NKBRSF fund (No. G1999032805) and Doctoral Funding of State Education Ministry
(No. 97014120). 相似文献
990.