有机、聚合物薄膜电致发光器件的研究进展

有机、聚合物薄膜电致发光器件是近年来国际上的一个研究热点。与无机材料相比, 有机材料具有更高的发光效率和更宽的发光颜色选择范围, 并且具有容易大面积成膜的优越性。本文介绍了有机、聚合物薄膜电致发光器件的结构和制备、发光机理以及有关材料的选择, 并对该研究领域的最新动态、器件的稳定性问题以及应用前景进行了讨论。     

含三苯胺的二苯乙烯化合物的合成及其电致发光性能

电致发光器件在光通讯、光信息处理、视频器件、测控仪器等光电子领域有着广泛而重要的应用价值.无机半导体二极管、半导体粉末、半导体薄膜等电致发光器件尽管已取得了令人注目的成就,但由于其复杂的器件制备工艺,高驱动电压、低发光效率,不能大面积平板显示,能耗较高以及难以解决短波长(如蓝光)等问题,使得无机电致发光材料的进一步发展受到一定的影响.相比之下,有机化合物可通过分子设计的方法合成数量巨大、种类繁多的有机化合物发光材料,使得有机材料构成的电致发光器件有着众多的优势,并成为目前电致发光领域的前沿研究课题之一.有关材料的制备^[1~3],发光机理^[4,5],电致发光器件的制备和性能^[6,7]的研究工作取得了相当大的进展.得到了各种发光颜色的器件,器件的发光亮度也较高.但由于电/光转换效率(量子效率)较低(小于10%),而且稳定性差,目前还只能制备出一些原型器件.     

基于离子型铱配合物的发光电化学池

基于离子型过渡金属配合物的发光电化学池在信息显示和固体照明方面极具应用前景,因此其相关材料的设计、开发和器件性能的提高等工作在近几年引起了人们广泛的研究兴趣。在各类离子型过渡金属配合物中,离子型铱配合物由于发光效率高,发光颜色容易调节等优点而受到广泛关注。本文综述了近几年来离子型铱配合物在发光电化学池中的应用进展,重点评述了不同发光颜色的发光电化学池的制备和器件的高性能化等方面的研究进展,并展望了基于离子型铱配合物的发光电化学池这一研究领域的发展前景。     

聚苯胺薄膜的溶液表面制备及室温氨气气敏性能

提出了一种基于溶液表面的聚苯胺(PANI)薄膜及气敏器件的室温制备方法,以苯胺单体、盐酸和过硫酸铵为原料通过氧化聚合在其水溶液表面直接获得质子化聚苯胺(PANI)薄膜,并利用薄膜的可转移特性构筑气敏器件.研究发现溶液的pH对PANI致密薄膜的形成至关重要,从而提出了质子化苯胺单体优先在溶液表面聚集和聚合的PANI薄膜形成机制.该薄膜气敏器件能够对NH₃进行有效的室温检测,且性能随薄膜聚合温度和聚合时间的变化呈规律性变化,优选制备条件下(pH=0.6,室温18℃,聚合60 min)的薄膜其检测下限为10^-6,响应与NH₃浓度呈良好的线性关系,并具有良好的重复性、选择性、快速响应和有竞争力的响应值.该薄膜制备工艺体现了“绿色”制备思想,且薄膜能够大面积制备并具有优异的气敏性能,有望为PANI-基薄膜的制备与室温气体传感器的研究与应用提供一种新的思路.     

聚集诱导发光材料在聚合物制备及性能检测中的应用进展

聚集诱导发光(AIE)材料因其独特的发光性能,已在荧光检测、生物成像及有机发光器件等领域展现出较为广阔的应用前景。本文综述了AIE材料在监测聚合物制备过程(本体聚合、溶液聚合、乳液聚合及悬浮聚合过程等)中的应用,介绍了利用AIE分子的荧光信号响应检测聚合物玻璃化转变温度、粘度、相分离程度、分子量等物理性能的研究,为AIE材料在聚合过程可视化监测及聚合物荧光功能化领域的应用提供了参考。最后对AIE材料在高分子科学研究中的应用前景进行了展望。     

化学修饰电极的研究 Ⅶ.电化学聚合法制备和研究乙烯二茂铁聚合物薄膜电极

聚合物薄膜电极具有电活性物的表面浓度高,稳定性好等优点,对电催化和电分析研究具有实际意义,是目前化学修饰电极发展的主要趋势。我们曾用电化学聚合法制备了二茂铁的羟基和酰基衍生物聚合物薄膜电极。本文用电化学聚合法-循环伏安(CV)法和恒电位氧化法研究了乙烯二茂铁(VFc)的聚合条件,分别以乙腈和乙醇为溶剂制备了VFc的聚合物(PVFc)薄膜电极,探讨了聚合反应机理。实验部分试剂:均为分析纯,水为二次蒸馏水。     

DOPANT EFFECTS OF SQUARYLIUM CYANINE DYES ON FUNCTIONAL DEVICES

本文初步研究了方酸菁染料在功能器件中的应用,并探讨了相关机理。我们用方酸菁掺杂8羟基喹啉铝发光层,获得了红光有机电致发光器件;用掺杂方酸菁的联吡啶钌作光敏剂修饰TiO₂纳晶薄膜电极,有效地弥补了联吡啶钌在600nm以上红光区采光能力的不足,从而大大提高了光电化学太阳电池的总体光电转换效率。     

咔唑基四苯乙烯多功能发光材料的合成与性能

设计合成了一个以四苯乙烯为核心,四端连接长烷基链的咔唑基四苯乙烯衍生物(TPECz),该化合物具有典型的聚集诱导发光(AIE)特性.紫外光谱(UV-Vis)、荧光光谱(PL)、热重(TG)和示差扫描量热(DSC)研究表明,该化合物属于深蓝光材料、具有较好的热稳定性,并且对金属Fe3+具有很好的识别作用,有望用于金属离子检测;同时,该化合物外围的咔唑基团具有电化学活性,采用电化学聚合方法可制备其聚合物交联荧光薄膜,扫描电镜(SEM)和原子力显微镜(AFM)研究表明,该荧光薄膜表面平整,有望用于制备有机电致发光器件(OLED),可见该化合物是一种多功能材料.     

导电高分子薄膜修饰电极的研究I. 聚吡咯薄膜电极的电化学合成及行为

利用在水溶液中的电化学聚合制备了聚吡咯烷、薄膜修饰电极. 讨论了对电化聚合的影响因素及薄膜修饰电极在不同电解质中的伏安特性, 从X-射线光电子能谱推测, 在吡咯的电化聚合过程中氧的参加引起在聚吡咯烷膜的结构中有羰基和羟基的生成.     

溶胶-凝胶工艺制备发光薄膜研究进展

本文综述了通过深胶－凝胶工艺制备发光薄膜的基本过程、薄膜的表征方法、发光薄膜的当前发展及应用情况。依据组成特点,对溶胶－凝胶法制备的发光薄膜乾地了分类阐述,并预言了今后该法制备发光薄膜的发展趋势。     

Electrochemical polymerization films for highly efficient electroluminescent devices and RGB color pixel

The electrochemical polymerization (EP) method to fabricate highly luminescent films and devices is rarely reported. It is typically believed that the organic light-emitting devices (OLEDs) made by EP method behave low performance because of the structural defects, doped electrolytes, and rough morphology in EP films. Here we present a new strategy to fabricate high-quality EP films including the special molecular design for EP precursors and the electrochemical control for EP processes. The resulting EP films exhibit high fluorescence, low doping levels, and smooth surface morphology. The efficiency of EP film devices arrive a level of >10 cd A^?1 (green-emission). Moreover, the full-color micropatterned EP films with sharp edge and high resolution have been achieved, demonstrating a new simple method for fabricating micropatterned luminescent polymers and devices compared with currently used techniques.     

稀土Eu(Ⅲ)双酞菁衍生物LB膜的荧光性

合成了八－４－（四氢糠氧基）酞菁铕（Ⅲ）,通过元素分析、红外光谱、质谱和紫外－可见光谱加以确认。测定了配合物的ＩＩ－Ａ曲线,证明它有很好的成膜性,Ｚ型沉积形成的ＬＢ膜材料有很强的荧光响应,随着ＬＢ膜厚度的增加,荧光性增强。掺杂邻菲咯啉形成的混合ＬＢ膜,其荧光性比纯膜强。但不是邻菲咯啉加入的量越多荧光性越强。配合物：邻菲咯啉＝１：１０时（摩尔比）,有最好的荧光行为。用电子光谱对ＬＢ膜的结构进行了表征     

Highly luminescent network films from electrochemical deposition of peripheral carbazole functionalized fluorene oligomer and their applications for light-emitting diodes

Highly luminescent network films on flat indium tin oxide (ITO) substrates are prepared by electropolymerization using an electroactive and fluorescent compound as precursor; the LEDs prepared using these films as a light emitting layer achieve the maximum luminance and external quantum efficiency of 4224 cd/m(2) and 0.72%, respectively, which demonstrates that electrochemical synthesis can be a new route to construct the highly luminescent films.     

Luminescence polarization spectroscopy study of functionalized carbon nanotubes in a polymeric matrix

Single-walled carbon nanotubes (SWNTs) were well-functionalized for a study of their defect-derived luminescence properties. The soluble nanotube sample was homogeneously dispersed in poly(vinyl alcohol) (PVA) films via solution-phase mixing and then wet-casting. The PVA films embedded with the functionalized SWNTs were strongly luminescent according to spectroscopic and confocal microscopic results. The luminescence from the films was highly polarized, with the observed anisotropy value approaching the limit for collinear absorption and emission dipole moments. The films were mechanically stretched to align the embedded nanotubes, and results from luminescence measurements of the stretched films suggested that the excitation was strongly in favor of the direction along the nanotube axis. Mechanistic implications of the polarization spectroscopy results for the luminescent functionalized nanotubes in the polymeric matrix with and without the mechanic alignment are discussed.     

Highly luminescent mono- and multilayers of immobilized CdTe nanocrystals: controlling optical properties through post chemical surface modification

The significant fluorescence enhancement of immobilized CdTe nanocrystals through chemical surface modifications is described, enabling us to fabricate stable, highly luminescent thin films and patterns of nanocrystal mono- and mutilayers.     

Electropolymerized AIE-active polymer film with high quantum efficiency and its application in OLED

A carbazole functionalized electro-active AIE-activity molecule, TPE-DFCz , was designed, synthesized, and well characterized. The clear difference in oxidation potentials between tetraphenylethylene (TPE) unit and carbazole groups was found which guaranteed that polymerization occurred only at the peripheral carbazole groups and the TPE unit remained unchanged. Its luminescent network film was prepared conveniently by electrochemical polymerization (EP). The cross-linked film exhibited green emission with high quantum efficiency of 63%, relatively smooth surface, and good thermal stability. The effect of different scan cycles on the optical property was also investigated. The electroluminescent device using the optimized polymer film as active layer showed a maximum luminance of 3200 cd m⁻² and a maximum luminance efficiency of 1.16 cd A⁻¹ with very low roll-off of the efficiency. The AIE-active EP films afford more opportunities to develop polymer films with high quantum efficiency via a simple, effective method and promote the potential applications in display devices. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 707–715     

Self-assemblies of luminescent rare earth compounds in capsules and multilayers

This review addresses luminescent rare earth compounds assembled in microcapsules as well as in planar films fabricated by the layer-by-layer (LbL) technique, the Langmuir–Blodgett (LB) method and in self-assembled monolayers. Chemical precipitation, electrostatic, van der Waals interactions and covalent bonds are involved in the assembly of these compounds. Self-organized ring patterns of rare earth complexes in Langmuir monolayers and on planar surfaces with stripe patterns, as well as fluorescence enhancement due to donor–acceptor pairs, microcavities, enrichment of rare earth compounds, and shell protection against water are described. Recent information on the tuning of luminescence intensity and multicolors by the excitation wavelength and the ratio of rare earth ions, respectively, are also reviewed. Potential applications of luminescent rare earth complex assemblies serving as biological probes, temperature and gas sensors are pointed out.     

Synthesis and sol–gel assembly of nanophosphors

Some recent works made in our group on inorganic nanophosphors are briefly reviewed in this paper. We first present the synthesis of highly concentrated semiconductor quantum dot colloids allowing the extension of the well-known oxide sol–gel process to chalcogenide compounds. Secondly, we show the synthesis and the chemical functionalization of lanthanide-doped insulator nanoparticles. In particular, the annealing process of these particles at high temperature leads to highly bright nanocrystals, which can be used as biological luminescent labels or for integration in transparent luminescent coatings. Finally, we consider luminescent transition metal clusters, which combine the inorganic structure of nanoparticles with the monodispersity and the easy functionalization of the organic molecules. Emphasis is put on the original thermochromic luminescence properties of copper iodide clusters trapped in siloxane-based films.     

Photophysical properties and tunable colour changes of silica single layers doped with lanthanide(III) complexes

Highly stable Eu(III) and Tb(III) complexes, emitting in the red and green visible regions, respectively, have been anchored onto a single SiO(2) transparent layer, yielding ca. 40 nm thick films; this allows high loading of tailored proportions of the red and green emitters within the films and results in highly uniform and easily colour-tunable luminescent layers.