高分子电致发光材料研究进展

综述了近几年来国内外关于高分子聚合物在电致发光材料领域的研究进展,重点介绍了聚苯撑乙烯、聚芴类、聚噻吩类聚合物及其衍生物的相关研究成果,并讨论了当前高分子电致发光材料存在的关键问题及应用前景.     

一种合成聚(2-甲氧基-5-(2''-乙基-己氧基)-对苯乙炔)的新方法

聚对苯乙炔(PPV)及其衍生物是制备聚合物发光二极管的最重要的聚合物之一[1].这主要是因为它们具有优越的电致发光性能,易于合成以及良好的环境稳定性[2].而聚(2-甲氧基-5-(2'-乙基-己氧基)-对苯乙炔)(MEH-PPV)由于其可溶性好,发光效率和亮度高,在电致发光领域广受关注.现在有许多MEH-PPV的多步化学合成方法以及电化学合成方法.但是,这些方法常常产率低,成本高且产品不纯.本文报道一种固/ 液两相反应一步合成分子量大、溶解性好的MEH-PPV的新方法.     

一种新型水溶性蓝光苯撑乙烯/甲基丙烯酸共聚物的合成

聚苯撑乙烯(PPV)由于其光致发光效率高、电荷传输性能好、可修饰等优点,自从1990年剑桥大学卡文迪许实验室实现其电致发光以来,一直是人们的研究热点．为了提高PPV的加工性能,人们用取代基增加其溶解性,经过适当修饰的PPV衍生物可溶于普通有机溶剂,具有良好的成膜性能．关于水溶性PPV研究的报道很少．通过自组装技术将水溶性共轭聚合物构建成发光材料及高敏感     

248 nm深紫外光刻胶用成膜树脂的研究进展

综述了用于248 nm化学增幅型深紫外光刻胶的不同种类和结构的成膜树脂,以及所使用单体的研发进展,包括聚甲基丙烯酸甲酯及其衍生物、聚对羟基苯乙烯及其衍生物、N取代的马来酰亚胺衍生物,以及其他聚合物等,对不同结构成膜树脂的曝光条件、对光刻胶性能的影响进行了介绍。     

聚对苯撑乙炔的合成及光谱性能-共轭主链被间位苯环阻隔

报道了一种阻隔型聚对幕撑乙炔((PPE)的合成与电致发光特性,合成的模型小分子证明,在聚对苯撑乙炔(PPV)主链引入间位幕环,可阻隔PPV的有效共轭长度,改变其发光颜色,研究了电致发光暑件ITO／m-PPE／Al的电致发光特性。     

一种含三苯胺链段的PPV类交替共聚物的合成、表征及性能

合成了三苯胺二醛和1-甲氧基-4-辛氧基-2,5-二甲苯双(三苯基氯化)两种单体,通过Wittig反应制得了共轭聚合物,对共轭聚合物进行了表征和性能测试.这类共轭聚合物的氯仿溶液和膜在紫外光激发下能发出强的蓝绿光,与小分子三苯胺衍生物(TPD)相比,具有相对较高的热稳定性和良好的成膜性.电化学分析表明聚合物具有很好的空穴传输能力.同时对共轭聚合物的光致发光和电致发光性能进行了研究,结果表明,此聚合物与同类聚对亚苯基亚乙烯基(PPV)型聚合物相比具有较低的驱动电压和较高的发光亮度,是一种潜在的有机高分子电致发光材料.     

含噁二唑的聚(间亚苯乙烯)电致发光二极管

1990年英国剑桥大学的Burroughes等人[1]以聚(对亚苯乙烯)为发光材料制备了第一个有机聚合物电致发光二极管,该工作引起了科学工作者的极大兴趣.聚合物材料具有很好的电、热稳定性以及机械加工和成膜性能,发光亮度和效率较高,通过化学修饰可获得三原色发光.而且聚合物电致发光二极管的工作电压较低,可实现大面积平板显示和集成化.     

聚对苯乙炔-噻吩共轭聚合物电致发光性能的研究

1990年剑桥大学的Ｂｕｒｒｏｎｇｈｅｓ[1] 等首次提出用共轭高分子聚 (苯乙撑 ) (ＰＰＶ)为发光层材料制备了聚合物电致发光器件 ,不久Ｈｅｅｇｅｒ[2 ] 等证实了这个结果 ,随后发光聚合物的研究在世界范围内广泛开展起来 ,ＰＰＶ目前已被证实是一个潜在的电致发光材料[3 ] .共轭聚合物用于电致发光有以下特点 :( 1 )可通过旋涂、浇铸等方法制成大面积薄膜 ;( 2 )共轭聚合物大多有优良的稳定性 ;( 3)共轭聚合物电子结构 ,发光颜色能够通过化学结构的改变和修饰进行调节 ;( 4 )聚合物做发光层时可制成非常薄的膜 ( 1 0～ 1 0 0ｎｍ) ,可消除…     

共轭型聚合物三阶非线性光学材料的研究进展

综述了近１０年共轭型聚合物三阶非线性光学材料取得的新进展。主要包括聚二乙炔及其衍生物、聚乙炔及其衍生物、聚噻吩及其衍生物、聚苯乙炔及其衍生物、聚苯腈及其衍生物以及聚苯胺类等。     

可溶性聚对苯乙炔的合成及其电致发光性能

采用紫外－可见光谱跟踪用直接聚合法制备可溶性的聚对苯乙炔衍生物的反应过程,结果表明反应仍然经历了生成前聚物的过程。控制反应条件使聚合反应首先生成前聚物,在前聚物烯化反应阶段加入起增溶作用的长链醇,得到了具有良好的溶解性的、主链中含非共轭链段的聚对苯乙炔衍生物。用该聚合物制备的电致发光器件,在５－６Ｖ电压驱动下发光,发光峰位于５８０ｎｍ左右。     

Study on the Synthesis of Poly(p-Phenylene Vinylene) Derivatives by Dehydrochlorination

The synthesis of poly(p-phenylene vinylene) (PPV) and its derivatives have aroused great interest^[1],since Burroughes^[2] discovered that PPV showed excellent electroluminescent (EL) properties. The conventional polymerization reactions, such as dehydrochlorination reaction,Wittig reaction and et al, usually afforded insoluble and/or infusible PPV and its derivatives, which shows inferior mechanical properties. Though the precursor polymer route can circumvent the insolubility of PPV, the strategy needs muti-step reaction and high temperature which affords the low yield and other disadvantageous^[3]. So the synthesis of soluble PPV derivatives with high yield are very fascinating.     

High-efficiency poly(p-phenylenevinylene)-based copolymers containing an oxadiazole pendant group for light-emitting diodes

A new series of high brightness and luminance efficient poly(p-phenylenevinylene) (PPV)-based electroluminescent (EL) polymers, poly[2-[4-[5-(4-(3,7-dimethyloctyloxy)phenyl)-1,3,4-oxadiazole-2-yl]phenyloxy]-1,4-phenylenevinylene] (Oxa-PPV), poly[2-[2-((3,7-dimethyloctyl)oxy)phenoxy]-1,4-phenylenevinylene] (DMOP-PPV), and their corresponding random copolymers, poly[[2-[4-[5-(4-(3,7-dimethyloctyloxy)phenyl)-1,3,4-oxadiazole-2-yl]phenyloxy]-1,4-phenylenevinylene]-co-[2-[2-((3,7-dimethyloctyl)oxy) phenoxy]-1,4-phenylenevinylene]] (Oxa-PPV-co-DMOP-PPV), with an electron-deficient 1,3,4-oxadiazole unit on the side groups, were synthesized through the Gilch polymerization method. The newly designed and synthesized asymmetric molecular structures of Oxa-PPV, DMOP-PPV, and Oxa-PPV-co-DMOP-PPV were completely soluble in common organic solvents, and defect-free optical thin film was easily spin-coated onto the indium tin oxide (ITO) substrate. Oxa-PPV shows a high glass transition temperature (T(g)), which might be an advantage for long time operation of polymer light-emitting diodes (PLEDs). Double-layer LEDs with an ITO/PEDOT/polymer/Al configuration were fabricated by using those polymers. Electrooptical properties and device performance could be adjusted by introducing the Oxa-PPV content in the copolymers. The emission colors could be tuned from green to yellowish-orange via intramolecular energy transfer. The improved device performance of Oxa-PPV over DMOP-PPV and Oxa-PPV-co-DMOP-PPV may be due to better electron injection and charge balance between holes and electrons and also efficient intramolecular energy transfer from 1,3,4-oxadiazole units to PPV backbones. The maximum brightness and the luminance efficiency of Oxa-PPV were up to 19395 cd/m(2) at 14 V and 21.1 cd/A at 5930 cd/m(2). The maximum luminance efficiency of Oxa-PPV is ranked the highest value among the PPV derivatives to date.     

Controlling layer thickness and photostability of water-soluble cationic poly(p-phenylenevinylene) in multilayer thin films by surfactant complexation

In this work we build on prior studies of the novel water-soluble cationic conjugated polymer known as "P2" (poly{2,5-bis[3-( N, N, N-triethylammonium bromide)-1-oxapropyl]-1,4-phenylenevinylene}) with a focus on its incorporation into thin films for such applications as photovoltaics or electroluminescent devices. Multilayer assemblies were constructed using P2, the anionic surfactant sodium dodecyl sulfate (SDS), and the polyanion poly(sodium 4-styrene-sulfonate) (PSS) using the technique of layer-by-layer electrostatic self-assembly (LBL-ESA). SDS was observed to affect the layer thicknesses and absorbance characteristics of the films. We show that the optical properties and photo-oxidative resistance can be improved by varying the SDS content in the assemblies. Specifically, the surfactant-complexed poly( p-phenylenevinylene) (PPV) shows an enhanced absorption at longer wavelengths as well as improved photostability. Therefore, our work may have broad implications on the development of stable PPV-based materials in general and their efficient integration into thin films technologies.     

Nonlinear optical properties of thin organic films

A brief survey is given on our recent work on the linear and nonlinear optical properties of thin films of polymers with a conjugated π–electron system. Third harmonic generation and degenerate four wave mixing experiments are used to study magnitude and response time of the third order nonlinear optical susceptibility of poly(p-phenylenevinylene) and poly(phenyl acetylene). Phthalocyanine derivatives show a strong influence of the intermolecular electronic coupling on the response time of transient gratings. The influence of energy transfer on the relaxation process is discussed.     

Synthesis and langmuir‐blodgett (LB) film properties of functional α,ω‐diamine amphiphilic materials

We have investigated the synthesis and ultrathin film forming properties of α,ω‐diamine derivatives. The amphiphiles were synthesized as precursors to the formation of ionene polymers. Two materials were investigated: oligothiophene and azobenzene functional groups. These type of materials are of great interest for the preparation of ultrathin film layers with applications for photochemical regulation of liquid crystal (LC) orientation, optical storage media, and electroluminescent displays. Azobenzene and its derivatives are well known photochemical systems exhibiting the reversible cis‐trans photoisomerization. Conjugated oligothiophene derivatives, exhibit interesting optical and electronic properties for applications such as light emitting diodes (LED)s, Schottky diodes, and thin film field‐effect transistors (TFT). The two amphiphiles behaved very differently as Langmuir monolayers and LB films. Dye aggregation was observed with the azobenzene derivatives compared with the oligothiophenes.     

Tuning the optical properties of a water-soluble cationic poly(p-phenylenevinylene): surfactant complexation with a conjugated polyelectrolyte

In this work, we investigate the emission and absorbance properties of the novel water-soluble cationic conjugated polymer poly{2,5-bis[3-(N,N,N-triethylammonium bromide)-1-oxapropyl]-1,4-phenylenevinylene}, denoted here as P2, in the presence of varying amounts of the anionic surfactant sodium dodecylsulfate (SDS). We show that the absolute photoluminescence quantum efficiency (PLQE), the absorption wavelength, and the emission wavelength of an aqueous solution of P2 can be adjusted according to the surfactant/polymer ratio in aqueous solution. In particular, we show that the addition of SDS to P2 increases the polyelectrolyte's PLQE to approximately 40%. An observed red shift in the emission spectra upon addition of the surfactant is attributed to the reduction in electrostatic repulsive interactions between side chains that minimize the benzene ring twisting along the backbone structure. At the surfactant's critical micelle concentration, the P2 chains wrap around the outer surface of the SDS micelles. This work has implications on the development of new stable poly(p-phenylenevinylene)-based photovoltaic and electroluminescent materials with tunable optical properties.     

Synthesis of a new conjugated 2,2′-(1,4-phenylenedivinylene)bis-quinoxaline and a series of styryl derivatives of quinoxaline and quinoline as promising electro- and photoluminescent materials

A new poly(p-phenylenedivinylene) oligomer 2,2'-(1,4-phenylenedivinylene)bisquinoxaline, a promising candidate in organic electroluminescent devices, was synthesised via a Knoevenagel condensation reaction of 2-methylquinoxaline with 1,4-benzenedicarbaldehyde. The same synthetic strategy was applied to obtain substituted styryl dyes, derivatives of quinoxaline, whereas styryl derivatives of quinoline were prepared by "Anil Synthesis". The considered dyes are of interest as fluorescence emitting materials. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 95–100, January, 2009.     

芴类电致发光材料研究进展

有机电致发光材料是光电信息功能材料领域的研究热点之一。相比于无机电致发光材料,有机电致发光材料具有很多的优势.芴类化合物作为一类具有刚性平面联苯结构的电致发光材料,由于具有宽的能隙、高的发光效率等特点,备受各方面的关注.本文结合作者的工作,从材料合成的角度介绍了国内外在研究该类材料方面所取得的一些最新进展,并对一些有待进一步研究的问题做了展望.     

"Click"-capture, ring-opening metathesis polymerization (ROMP), release: facile triazolation utilizing ROMP-derived oligomeric phosphates

Soluble, high-load ring-opening metathesis polymerization (ROMP)-derived oligomeric triazole phosphates (OTP) are reported for application as efficient triazolating reagents of nucleophilic species. Utilizing a "Click"-capture, ROMP, release protocol, the efficient and purification-free, direct triazolation of N-, O-, and S-nucleophilic species was successfully achieved. A variety of OTP derivatives were rapidly synthesized as free-flowing solids on a multigram scale from commercially available materials.