聚合物电致发光二极管热特性研究

采用ANSYS有限元分析软件中热分析结构单元,对聚合物电致发光二极管(PLED)在光强为1000cd/m2时的热特性进行模拟,获得其温度场、热流分布及温度梯度的分布图,从仿真结果知PLED器件的最高温度为45.968℃,处于PFO-BT发光层,最低温度为45.95℃,处于石英玻璃基底末端.计算得出聚合物发光器件总热阻为1305℃/W,聚合物发光层至石英玻璃基底末端热阻为1℃/W.通过改变PLED器件输入功率、基底材料以及基底厚度3个参数,分别模拟得出其对PLED器件热特性的影响,仿真结果表明器件最高温度TH与输入功率P显现良好的线性关系;不同基底材料对器件温度影响小,负极端为器件主要散热通径;当基底厚度不断增加时,PLED器件最高温度随着增加,而最低温度不断减少,器件总热阻基本不变,发光层至石英基底末端热阻线性增大.     

聚合物发光电化学池

聚合物发光电化学池(polymer light-emitting electrochemical cell,PLEC)作为一种新型的聚合物发光二极管(polymer light-emitting diodes,PLED),它的本质特征是在PLED活性层掺杂电解质以提高活性层载流子传输能力,由于其具有对电极金属功函数不敏感和量子效率高等诸多优点而受到广泛关注。本文从活性层配方的改良、电极金属及基板的表面处理、相容性的改善、固定p-n结的实现和引入热处理手段等方面综述了近几年PLEC的研究进展,分析了当前PLEC在电致发光领域面临的问题,并对PLEC的前景进行了展望。     

磺酸盐取代三苯胺类共轭聚电解质的合成及应用研究

通过水相Suzuki偶合反应合成了两种磺酸盐基团取代的三苯胺类共轭聚电解质PTP11和PTP31,对其化学结构进行了表征.通过对其光学和电化学性能进行测试得知,此类聚合物具有和ITO功函数相近的HOMO能级及较高的LUMO能级.磺酸盐基团的存在使得此类聚电解质具有和电中性聚合物所不同的溶解性,当其作为空穴传输材料应用于多层结构的聚合物电致发光器件(PLED)中时,可有效避免空穴传输层-发光层之间的界面混溶问题.以这两种聚合物作为空穴传输材料应用于以PFO-DBT15为发光层的红光PLEDs中时,器件的性能得到了显著提高.此外,磺酸盐基团的不同取代方式会对器件的性能产生一定的影响.     

BBDMS-PPV/ITO界面结构ADXPS研究

聚合物电致发光器件（Polymer Electroluminescent Device,PLED)已显示出广阔的应用前景^[1-6]。已往人们比较重视阴极材料的选择及相关金属与有机界面的研究^[7],而有关发光层或空穴传输层与阳极ITO膜之间的界面结构及化学问题则少见报道。事实上,ITO膜与有机层之间的作用对器件的可靠性及寿命具有更为严重的影响^[8,9]。由于异质界面的过渡层结构复杂,以纳米尺度上化学组成是非计量比的,因此对这种极薄的埋藏界面的研究方法还需进一步探索。本文通过模型试样制备和变角X射线光电子谱（ADXPS）技术,对PLED中共轭导电聚合物聚2,5－二（二甲基正丁基硅基）对苯乙烯撑（BBDMS－PPV）与阳极ITO膜所形成的界面结构进行了初步研究。     

利用三线态激子提高有机/高分子发光器件的量子效率

有机/高分子电致发光器件(O/PLED) 的发光效率远低于理论值,除器件结构有待优化之外,大部分三线态激子的能量没有得到利用是主要原因.近年来,利用三线态激子的发光来提高O/PLED的发光效率取得了积极的进展.本文从利用三线态激子的发光机制入手,综述了国内外在高效发光领域磷光材料利用的主要研究进展及发展方向。     

Novel Blue Light-emitting PPV-based Copolymer Containing Triazole and Carbazole Units

For making the polymer light-emitting diode (PLED) device with good performance, it is desirable to reach the balance of electron and hole injection. However, for most conjugated polymer, hole injection is more favorable than electron injection. So it is important to design and synthesize the bipolar conjugated polymer with both electron and hole transporting ability for the fabrication of single-layer PLED1-2. In this communication we present the synthesis and preliminary characterizatio…     

高分子电致发光材料结构设计方法概述*

高分子发光二极管（PLED）因其巨大的科学和商业价值而得到了广泛关注,近年来各种新材料的不断开发和深入研究使PLED器件日益走向实用化。高分子电致发光材料的结构设计是新材料开发的灵魂,本文结合我们的工作概述了高分子发光材料结构设计的基本原理和设计要点,详细介绍了单分子结构设计方法及其相关的基本思路和理论,分析了聚集态结构对材料及其器件性能的影响,概括了聚集态结构设计的一些基本方法。最后提出了高分子发光材料结构设计的一般性思路,并展望了其研究和发展方向。     

PREFACE

正Polymer electronics are one of the most active research areas in material science,information science and energy science,because it can offer new ways to create a new generation of large area,flexible and low cost electronics.For example,a voltage is applied to a polymer,which can emit light such as RGB three primary color for full color PLED(Polymer Light-emitting Diodes),even white light for white PLED.In turn,light is absorbed by a polymer to produce electric current,that     

响应性支化聚合物的合成、组装及其生物医药应用

环境响应性超支化聚合物作为超支化聚合物中一类智能聚合物,备受研究者关注,已被广泛用于生物医药领域.本文主要介绍了本课题组在响应性支化聚合物的合成、组装及其生物医药应用方面的部分研究工作.主要包括以下三方面的内容:第一部分介绍了酸响应性支化聚合物、温敏性支化聚合物、还原响应性支化聚合物和光响应性支化聚合物的合成;第二部分介绍了含有二硫键的温敏性超支化聚合物在温度诱导下的自组装及自交联反应制备纳米凝胶、纳米胶囊和交联复合囊泡;第三部分介绍了响应性支化聚合物在药物传递和基因传递方面的应用.     

PREFACE

Polymer electronics are one of the most active research areas in material science,information science and energy science,because it can offer new ways to create a new generation of large area,flexible and low cost electronics.For example,a voltage is applied to a polymer,which can emit light such as RGB three primary color for full color PLED (Polymer Light-emitting Diodes),even white light for white PLED.In turn,light is absorbed by a polymer to produce electric current,thatis,polymer solar cells (PSCs).     

Novel Conjugated Side Chain Fluorinated Polymers Based on Fluorene for Light-Emitting and Ternary Flash Memory Devices

Three novel conjugated polymers based on 9,9′-dioctylfluorene unit and isoindolo[2,1-a]benzimidazol-11-one with different fluorine substituents (0, 2 and 4) were synthesized. PLED and resistive memory devices based on these polymers were prepared consequently. PLED based on four-fluorinated polymer showed the highest maximum brightness of 3192 cd m⁻² with almost 5-fold increase of current efficiency 8-fold increase of external quantum efficiency compared to that of the other two, and all the PLEDs exhibited good emission stability with no noticeable change of electroluminescence even under high voltage of 10 V. The memory device of doubly-fluorinated polymer exhibited ternary flash behavior with threshold voltages below −2.5 V, while device of four-fluorinated polymer possessed ON/OFF current ratio above 10⁴. Impact of fluorine substitutions on the performance of devices were briefly investigated. The results revealed that the improvement of device performance might not scale with the increasing number of fluorine substitutions, and the four-fluorine-substituted polymer and doubly-fluorinated polymer could be encouraging materials for applications of PLED and resistive memory device and worth of further design of other new polymer systems.     

Creating a pseudometallic state of K+ by intercalation into 18-crown-6 grafted on polyfluorene as electron injection layer for high performance PLEDs with oxygen- and moisture-stable Al cathode

Polymer light-emitting diodes (PLEDs) suffer from inadequate lifetimes because of the use of environmentally sensitive metals as the cathodes. We present the use of water/methanol-soluble polyfluorene grafted with 18-crown-6 chelating to K(+) as the electron-injection layer (EIL) for deep-blue-emission PLEDs, allowing the use of environmentally stable Al as the cathode since electron donation from the 18-crown-6 can reduce K(+) to a stable "pseudometallic state", enabling it to act as an intermediate step for electron injection. Furthermore, when poly(ethylene oxide) was blended into the EIL to provide hole blocking (HB), the device exhibited the highest performance reported to date for a deep-blue-emission PLED based on a conjugated polymer as the emitting layer, with a brightness of 54,800 cd/m(2) and an external quantum efficiency of 5.42%. The use of such an EI-HB layer opens a broad avenue leading toward industrialization of PLEDs.     

聚芳烃二乙炔类共轭高分子的合成及其发光性质的研究

通过Glaser-Hay氧化偶联反应合成含有咔唑与对烷氧基苯结构单元的聚芳烃二乙炔。利用核磁共振、红外光谱、凝胶渗透色谱、紫外光谱、电致发光光谱、热重分析等测试手段表征其结构,测定相对分子质量及其分布,并研究光学、热学和电化学方面的性能。并将这种聚合物作为器件的发光层,其器件结构为ITO/PEDOT/Polymer/Ba/Al,结果表明起亮电压为6.5V,其外量子效率达到0.21%,最大亮度达到90 cd/m2。     

Synthesis,characterization, and electrogenerated chemiluminescence of deep blue emitting eumelanin‐inspired poly(indoylenearylene)s for polymer light emitting diodes

Deep blue emitting copolymers were synthesized by uniting the Eumelanin‐inspired indole core with fluorene and carbazole units via Suzuki polymerization. The resulting polymers, PIF and PIC, showed deep blue emission in the range of 416–418 nm and quantum yields of 0.39–0.60. Both polymers exhibited an intense and stable electrogenerated chemiluminescence. Interestingly, deep HOMO levels of −5.71 and −5.61 eV were observed for PIF and PIC, respectively. Solution processed polymer light emitting diodes (PLEDs) were fabricated using the PIF as a guest. PLEDs emitted deep blue light at 418 nm, with the luminous efficiency peaking at 1 Cd/A, given that the photopic response at that wavelength is 0.0151. The electroluminescence of PIF displayed a Commission Internationale de l'Eclairage coordinates of (0.16, 0.07) with a maximum external quantum efficiency of 1.1%. Hence, these materials prove to be promising candidates for the fabrication of deep blue PLEDs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 125–131     

New cyanopyridine‐based π‐conjugative poly(azomethine)s: Synthesis,characterization and electroluminescence studies

Four new Schiff‐base type conjugative polymers (CPs), that is, Py _1‐4 carrying a strong electron‐withdrawing cyanopyridine scaffold coupled with different electron‐donating aromatic/heteroaromatic moieties were synthesized from their respective co‐monomers by simple poly‐condensation route. They were subjected to structural, thermal, photophysical, and electrochemical characterizations and theoretical investigations in order to identify their suitability in polymer light‐emitting diode (PLED) application. All these polymers showed good film‐forming ability and exhibited favorable photophysical behaviors with an optical bandgap in the order of 2.54‐2.68 eV. Further, their electrochemical data were used to evaluate highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels. Finally, Py _1‐4 were successfully employed as blue‐light emitter in the construction of new ITO/PEDOT:PSS/ Py _1‐4 /Al configured light‐emitting diodes (LED), and the fabricated devices demonstrated stable blue electroluminescence behavior endorsing an effective electrons injection in the PLEDs.     

The specific effect of graphene additives in polyaniline-based nanocomposite layers on performance characteristics of electroluminescent and photovoltaic devices

A comparative study of the effect of graphene admixture to polyaniline hole-injection layers of polymer light emitting diodes (PLEDs) and anode buffer layers of organic solar cells (OSCs) has been performed. The layers have been made from the complex of polyaniline with poly-2-acrylamido-2-methyl-1propanesulfonic acid with (or without) addition of 1 wt % graphene prepared by the mechanochemical method. It has been shown that the effects of the graphene addition into the auxiliary PLED and OSC layers are opposite: performance characteristics (current and light efficiency) of the former deteriorate and those of the latter are improved (in particular, the powerconversion efficiency increases by a factor of 1.4). The reasons considered to be behind the opposite effects are a significant difference in the currents flowing through the PLED and OSC, a more developed interface between the OSC anode buffer layer and photolayer, and channeling the longitudinal conductivity at the interface between graphene nanoparticles and polyaniline.     

胺烷基侧链取代三苯胺类红光聚合物的合成及性能研究

通过Suzuki偶合反应合成了一系列胺烷基侧链取代的基于三苯胺和芴的共轭聚合物聚[4-(N,N-二甲基胺丙氧基)苯-4,4′-二苯胺-9,9-二辛基芴-4,7-二噻吩-2-基-2,1,3-苯并噻二唑](PFTD), 并对其化学结构和光电性能进行了表征. 末端胺基的存在提高了此类聚合物作为发光层应用于聚合物电致发光器件的性能(采用高功函数的金属铝作为阴极时). 结构为ITO/PVK/PFTD-5(DBT摩尔分数为5%时的聚合物)/Al的器件最大电致发射峰位于647 nm, 最大外量子效率达到了1.24%.     

Self-assembled zinc(II) Schiff base polymers for applications in polymer light-emitting devices

Thermally stable zinc(II) Schiff base polymers (decomposition temperature up to 461 degrees C; M(n)= 13580 to 20440) formed by self-assembly reactions of zinc(II) salts and salicylaldimine monomers exhibit blue to yellow PL with quantum yields up to 0.34 in DMF; PLEDs employing these polymers as emitters give green or orange EL with turn-on voltage at 5 and 6 V and maximum efficiency of 2.0 and 2.6 cd A(-1) respectively.     

Controlling ion motion in polymer light-emitting diodes containing conjugated polyelectrolyte electron injection layers

The properties and function of an anionic conjugated polyelectrolyte (CPE)-containing ion-conducting polyethylene oxide pendant (PF(PEO)CO(2)Na) as electron injection layers (EILs) in polymer light-emitting diodes (PLEDs) are investigated. A primary goal was to design a CPE structure that would enable acceleration of the device temporal response through facilitation of ion motion. Pristine PLEDs containing PF(PEO)CO(2)Na exhibit luminance response times on the order of tenths of seconds. This delay is attributed to the formation of ordered structures within the CPE film, as observed by atomic force microscopy. Complementary evidence is provided by electron transport measurements. The ordered structures are believed to slow ion migration within the CPE EIL and hence result in a longer temporal response time. It is possible to accelerate the response by a combination of thermal and voltage treatments that "lock" ions within the interfaces adjacent to PF(PEO)CO(2)Na. PLED devices with luminance response times of microseconds, a 10(5) fold enhancement, can therefore be achieved. Faster luminance response time opens up the application of PLEDs with CPE layers in display technologies.     

Hole‐transporting host‐polymer series consisting of triphenylamine basic structures for phosphorescent polymer light‐emitting diodes

A series of novel styrene derived monomers with triphenylamine‐based units, and their polymers have been synthesized and compared with the well‐known structure of polymer of N,N′‐bis(3‐methylphenyl)‐N,N′‐diphenylbenzidine with respect to their hole‐transporting behavior in phosphorescent polymer light‐emitting diodes (PLEDs). A vinyltriphenylamine structure was selected as a basic unit, functionalized at the para positions with the following side groups: diphenylamine, 3‐methylphenyl‐aniline, 1‐ and 2‐naphthylamine, carbazole, and phenothiazine. The polymers are used in PLEDs as host polymers for blend systems with the following device configuration: glass/indium–tin–oxide/PEDOT:PSS/polymer‐blend/CsF/Ca/Ag. In addition to the hole‐transporting host polymer, the polymer blend includes a phosphorescent dopant [Ir(Me‐ppy)₃] and an electron‐transporting molecule (2‐(4‐biphenyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole). We demonstrate that two polymers are excellent hole‐transporting matrix materials for these blend systems because of their good overall electroluminescent performances and their comparatively high glass transition temperatures. For the carbazole‐substituted polymer (T_g = 246 °C), a luminous efficiency of 35 cd A^?1 and a brightness of 6700 cd m^?2 at 10 V is accessible. The phenothiazine‐functionalized polymer (T_g = 220 °C) shows nearly the same outstanding PLED behavior. Hence, both these polymers outperform the well‐known polymer of N,N′‐bis(3‐methylphenyl)‐N,N′‐diphenylbenzidine, showing only a luminous efficiency of 7.9 cd A^?1 and a brightness of 2500 cd m^?2 (10 V). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3417–3430, 2010