电磷光发光聚合物*

电致磷光材料可以同时利用单线态和三线态激子发光,具有较高的发光效率,受到人们广泛的关注。本文综述了近年来通过共价键将磷光配合物单元连接在高分子链上制备电磷光发光聚合物的研究进展。总结了主链型、侧链型以及超支化结构的电磷光发光聚合物的研究进展,评述了上述几类电磷光聚合物的发光性能与分子结构的关系。最后从电磷光发光聚合物的分子结构设计出发,在电磷光发光聚合物领域业已取得进展的基础上,分析了电磷光发光聚合物在电致发光领域应用中存在的一些问题,并展望了电磷光聚合物今后的发展方向。     

New carbazole-containing polyphenylquinoxalines: Synthesis,photophysical, and electroluminescent properties

New carbazole-containing polyphenylquinoxalines combining the electron-transport behavior of quinoxaline with hole-transport and electroluminescent properties of carbazole have been synthesized. The polymers show solubility in organic solvents. Their glass transition temperatures range from 315 to 370°C, and temperatures corresponding to 10% weight loss vary from 510 to 560°C (in air). It has been demonstrated that these polymers exhibit electroluminescent behavior in the 450–750 nm spectral region and offer promise as emitting and electron-hole transport materials for polymeric light-emitting diodes.     

High-efficiency red-light emission from polyfluorenes grafted with cyclometalated iridium complexes and charge transport moiety

We report a new route for the design of electroluminescent polymers by grafting high-efficiency phosphorescent organometallic complexes as dopants and charge transport moieties onto alky side chains of fully conjugated polymers for polymer light-emitting diodes (PLED) with single layer/single polymers. The polymer system studied involves polyfluorene (PF) as the base conjugated polymer, carbazole (Cz) as the charge transport moiety and a source for green emission by forming an electroplex with the PF main chain, and cyclometalated iridium (Ir) complexes as the phosphorescent dopant. Energy transfer from the green Ir complex or an electroplex formed between the fluorene main chain and side-chain carbazole moieties, in addition to that from the PF main chain, to the red Ir complex can significantly enhance the device performance, and a red light-emitting device with the high efficiency 2.8 cd/A at 7 V and 65 cd/m2, comparable to that of the same Ir complex-based OLED, and a broad-band light-emitting device containing blue, green, and red peaks (2.16 cd/A at 9 V) are obtained.     

Electric-field-induced spin accumulation in polymer light-emitting diodes

An electric-field-induced spin accumulation phenomenon is presented for electroluminescent conjugated polymers as light-emitting diodes (LEDs). When an electric field is applied along a polymer chain and exceeds a critical value, it quenches the luminescence and dissociates the singlet exciton into two carriers with opposite spin signs. Simultaneously, the field drives these two opposite spin carriers to move in opposite directions, leading to spin accumulation at the two ends of the organic material LED, which can be detected through Kerr rotation microscopy.     

聚合物电致发光材料及其发光颜色调节的研究进展

聚合物电致发光材料已成为功能材料研究领域的一个热点.与无机材料和有机小分子材料相比,聚合物发光材料具有来源广泛、易加工成型、通过分子结构设计可调节发光颜色等优点,成为制备大面积、低成本、全色柔性显示器件的首选材料.本文介绍了聚合物发光材料的发光机理及调节发光颜色的常用方法,综述了聚对苯乙炔类、聚对苯类、聚芴类等多种共轭聚合物发光材料的合成及发光颜色调节的研究现状,并对聚合物发光材料的发展趋势以及聚合物电致发光器件的制备进行了评述和展望.     

New applications of poly(arylene ether)s in organic light-emitting diodes

Compared with conventional π-conjugated polymers,poly(arylene ether)s(PAEs) may take advantages of excellent thermal properties,well-defined effective conjugated length and no catalyst contamination.Recently,their applications have been extended from engineering plastics to optoelectronic materials.In this review,various kinds of functional PAEs used as fluorescent polymers,host polymers and phosphorescent polymers in organic light-emitting diodes(OLEDs) are outlined,and their molecular design,synthesis and device performance are overviewed.     

电注入发光聚合物的能带工程

聚合物发光二极管以其独有的优点在显示方面显现了光明的前景，关于它的研究也很快成为国际上竞争激烈的热点。目前，聚合物发光二极管的各项性能距实际应用的要求还有相当一段距离。在提高聚合物发光二极管的各项性能的进程中，电注入发光聚合物的能带工程将起着积极的作用。本文简要地介绍了电注入发光聚合物的能带的形成、表征以及能带工程在聚合物发光器件中的应用。     

树枝状有机电致发光材料*

高度有序、三维结构的树枝状大分子(Dendrimers)作为功能有机材料越来越引起人们的兴趣。与传统的小分子和高分子发光材料相比,树枝状化合物在发光材料方面的应用具有无可比拟的优势。树枝状发光材料的发光特性可以方便地由中心核的调换不同的荧光染料来实现,另外大量的表面功能团和不同的代数可供选择来得到一些有趣的性质,如载流子传输功能、区域隔离效应、溶解性和天线效应等。该类型的发光材料已被认为是第三类电致发光材料。本文简要介绍近期树枝状分子在有机电致发光材料领域中的研究进展,评述树枝状分子在该研究领域所特有的优势,重点介绍了树枝状化合物的设计及其对应的性质,并进一步展望树枝状分子未来在有机电致发光领域的研究前景。     

Gas transport properties of novel poly(arylene ether ketone)s containing dibenzoylbiphenyl and benzonaphthone moieties

In this work we present the results from studies on novel poly(arylene ether ketone)s, including gas permeability, wide-angle x-ray diffraction (WAXD), and dynamic mechanical analysis (DMA). Poly(arylene ether ketone)s containing 2,2′- and 3,3′-dibenzoylbiphenyl (DBBP) moieties were characterized to study the effect of biphenyl substitution on gas transport properties. Gas permeabilities of naphthalene-containing poly(arylene ether ketone)s were also measured. Higher permeabilities were observed for polymers prepared with 6F-BPA, compared to 9,9-bis(4-hydroxyphenyl)fluorene (HPF). The naphthalene-containing polymers exhibited higher permeabilities than the DBBP polymers, except for a polymer having the 2,2′-DBBP and tetramethylbiphenyl moieties. Based on our work, and results reported in the literature, the 3,3′-DBBP polymers showed the lowest permeabilities for DBBP-containing poly-(arylene ether ketone)s. The low permeabilities are due to more efficiently packed chains brought on by greater flexibility of the backbone, compared to the other polymers studied. DMA studies confirmed the higher barriers to rotation which are believed to be responsible for 2,2′-DBBP polymers having similar selectivities compared to 3,3′-DBBP polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 425–431, 1998     

Low molecular weight and polymeric heterocyclics as electron transport/hole-blocking materials in organic light-emitting diodes

The use of low molecular weight, oligomeric and polymeric heterocyclics as electron transport/hole-blocking layers in organic light-emitting diodes is reviewed. The most widely applied materials are π-electron deficient heterocyclics carrying imine nitrogen atoms in the aromatic ring, such as 1,3,4-oxadiazoles, 1,2,4-triazoles, 1,3,5-triazines, and 1,4-quinoxalines. Properties such as redox potentials, ionization potential, electron affinity and charge transport mobility of the materials, if known, are taken into consideration to support the electron injection/transport and hole-blocking effectiveness. It can be generalized that heterocyclic moieties with high reduction potential reduce the interface barriers caused by the band offset between organic material and cathode and are most suitable materials for electron injection in organic electroluminescent devices. These materials are generally characterized by high ionization potential values that contribute towards the hole-blocking property. A general comparison of devices and materials is only possible with limitations owing to the variations in device structure, fabrication, electrode materials, emitter materials, etc. © 1998 John Wiley & Sons, Ltd.     

Aromatic polyethers with 1,3,5-triazine units as hole blocking/electron transport materials in leds

Various difluoro functionalized aromatic 1,3,5-triazine monomers were prepared. A series of poly-(1,3,5-triazine-ether)s was synthesized by polycondensation with 4,4′-(hexafluoroisopropylidene)diphenol. The polymers have excellent thermal stability and are amorphous with glass transition temperatures in the range of 190–250°C. In order to examine the potential to apply these polymers in organic electroluminescent devices, the redox properties were studied by cyclic voltammetry. It was found that the monomers have high electron affinity and reach LUMO values in the range of −2.7 to −3.1 eV. This opens the possibility to utilize 1,3,5-triazine containing materials as electron injecting/hole blocking layer in LEDs. First LED results are in accordance to these high electron affinities.     

以铱为内核的有机电致磷光材料

有机电致磷光材料可以同时利用单线态和三线态激子发光,具有发光效率高等优点,成为近年来研究的热点。本文综述了以铱为内核的有机电致磷光材料的研究进展、存在问题和研究趋势,并简要介绍了用于制作有机磷光器件的主体材料。     

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.     

基于磷光材料的电致发光二极管研究进展

电致发光二极管(LEDs)具有能耗低、寿命长、绿色环保等优点,在固态照明、全色显示等领域具有广阔的应用前景。 与传统的荧光电致LEDs相比,磷光电致LEDs能够同时利用单重态和三重态激子,理论上可以使器件的内量子效率达到100%,突破5%的外量子效率极限。 因此,发展高效的磷光材料以及实现其在电致LEDs中的应用是非常有意义的。 本文综述了目前主要的磷光材料,包括有机金属配合物、纯有机分子、聚合物、金属有机框架材料和碳量子点等,并总结了稀有金属配合物和纯有机分子在电致磷光 LEDs中的研究进展,同时对电致磷光LEDs的发展前景进行展望。     

Synthesis of poly(arylene ether)s containing hole‐transport moieties from an isocyanate masked bisphenol

The design and synthesis of novel charge (hole‐ or electron‐) transport materials have been the focus of much research in recent years because of their wide variety of applications. In this study, three high molecular weight poly(arylene ether)s, 6a–c, containing naphthyl‐substituted benzidine moieties have been synthesized from carbamates derived from bisphenols. After masking with n‐propyl isocyanate, the carbamate is stable, can be readily purified by recrystallization from toluene, and can be polymerized directly with difluoro compounds under mild conditions. The resulting polymers possess high glass‐transition temperatures, excellent thermal stability, and good film‐forming properties. In comparison, the poly(arylene ether)s 6a′–c′, synthesized from unprotected bisphenol, have lower molecular weights and wider polydispersity and contain some brown impurities. Preliminary experiments show that both 6a and 6a′ can function well as hole‐transport materials in light‐emitting diodes. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2740–2748, 2000     

Progress in small-molecule luminescent materials for organic light-emitting diodes

Organic light-emitting diodes(OLEDs) have been extensively studied since the first efficient device based on small molecular luminescent materials was reported by Tang. Organic electroluminescent material, one of the centerpieces of OLEDs, has been the focus of studies by many material scientists. To obtain high luminosity and to keep material costs low, a few remarkable design concepts have been developed. Aggregation-induced emission(AIE) materials were invented to overcome the common fluorescence-quenching problem, and cross-dipole stacking of fluorescent molecules was shown to be an effective method to get high solid-state luminescence. To exceed the limit of internal quantum efficiency of conventional fluorescent materials, phosphorescent materials were successfully applied in highly efficient electroluminescent devices. Most recently, delayed fluorescent materials via reverse-intersystem crossing(RISC) from triplet to singlet and the "hot exciton" materials based on hybridized local and charge-transfer(HLCT) states were developed to be a new generation of low-cost luminescent materials as efficient as phosphorescent materials. In terms of the device-fabrication process, solution-processible small molecular luminescent materials possess the advantages of high purity(vs. polymers) and low procession cost(vs. vacuum deposition), which are garnering them increasing attention. Herein, we review the progress of the development of small-molecule luminescent materials with different design concepts and features, and also briefly examine future development tendencies of luminescent materials.     

基于2,1,3-苯并噻二唑衍生物的有机发光材料的设计与性质的理论研究

有机电致发光材料已经成为国际上的一个研究热点。利用量子化学方法研究有机电致发光材料的结构与性能间的关系已成为材料科学中不可或缺的重要手段。本文采用理论计算方法对一种2,1,3-苯并噻二唑衍生物的结构进行修饰,研究了杂原子NH、O和Se取代对电子性质、光谱性质、电荷传输性质以及稳定性的影响,这对于了解有机电致发光材料的发光机制,设计新颖的多功能材料是非常有意义的。研究结果表明,NH取代对母体分子的电子性质和光谱性质的影响最明显。NH、O和Se取代衍生物具有较小的空穴重组能,可以作为有机电致发光二极管中的空穴电荷传输材料。静电势能结果表明NH、O和Se取代衍生物的稳定性要高于母体分子的稳定性。     

New Semiconducting Poly(arylene sulfide)s: Synthesis,Characterization, and Optical Properties

New semiconducting soluble poly(arylene sulfide)s were synthesized by Wittig polycondensation. The arylene moieties consist of distyrylbiphenyl (P1) and distyrylbithiophene (P2) π-conjugated systems. The polymers are fully amorphous and show good thermal stability. The absorption and photoluminescence properties of the polymers were investigated. P1 film has an optical gap of 2.95 eV and exhibits green-blue fluorescence. P2 shows a longer effective conjugation length with a gap of 2.42 eV and emits in the orange region. The HOMO/LUMO energy levels were estimated by cyclic voltammetry measurements. Single-layer diodes were fabricated and show relatively low turn-on voltages.     

单分子有机电致白光材料及器件

有机电致白光二极管在白光照明和背光源应用中具有材料来源广、驱动电压低、节能和环保等优点,受到了广泛关注。目前实现电致白光的方法主要有小分子掺杂、多层器件、激基复合物和缔合物发光以及单分子白光等方法。其中,单分子白光材料由于要控制能量的不完全传递、单分子实现多色同步发射和优化器件结构等,目前研究得还比较少,器件的总体性能相对还不是很理想。本文从材料合成的角度,简要综述了国内外在单分子白光材料的合成与器件性能优化方面所取得的研究进展,并对下一步需要研究的热点问题作了展望。     

Facile synthesis of ortho‐Phenylene‐based conjugated polymers through transformation of cross‐conjugated poly(2,3‐diaryl[2]dendralene)s and their optical properties

We studied the facile synthesis of ortho‐phenylene‐based conjugated polymers through transformation of cross‐conjugated polymers having [2]dendralene moiety, poly(2,3‐diaryl[2]dendralene)s ( P1 s), and demonstrated the sequential synthesis of (Z)‐alkene‐ and ortho‐arylene‐containing conjugated polymers from P1 s. P1 s were transformed into cyclohexa‐1,4‐diene‐containing conjugated polymers ( P2 s) through a Diels–Alder reaction. Aromatization of the cyclohexa‐1,4‐diene skeleton was achieved by using 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone to give the ortho‐phenylene‐containing conjugated polymers ( P3 s). The ultraviolet–visible and fluorescence spectra of the cross‐conjugated polymers P1 s, and the conjugated polymers P2 s and P3 s indicated that the π–π interactions between the arylene moieties in P2 s were stronger than those in P1 s and P3 s. The synthetic method for P2 s and P3 s offers an effective synthesis of various types of (Z)‐alkene‐ and ortho‐arylene‐containing conjugated polymers. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 827–832