Hole injection/transport materials derived from Heck and sol-gel chemistry for application in solution-processed organic electronic devices

An organosilicate polymer, based on N,N'-diphenyl-N,N'-bis(4-((E)-2-(triethoxysilyl)vinyl)phenyl)biphenyl-4,4'-diamine (TEVS-TPD) with extended conjugation between the Si atom and the aromatic amine, was prepared under mild conditions via sequential Heck and sol-gel chemistry and used as an alternative to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the most widely used planarizing hole injection/transport layer in solution-processed organic electronic devices. Spin-coating TEVS-TPD polymer solutions yield defect-free, uniform, thin films with excellent adhesion to the ITO electrode. Upon thermal cross-linking at 180 °C, the cross-linked polymer exhibits excellent solvent resistance and electrochemical stability. Solution-processed organic light emitting diode (OLED) devices using iridium-based triplet emitting layers and cross-linked TEVS-TPD films as a hole injection/transport layer show significantly improved performance including lower leakage current, lower turn-on voltage, higher luminance, and stability at high current density, as compared to the control device prepared with PEDOT:PSS.     

聚合物与有机染料多层复合膜电致发光颜色的直流电压调制

聚合物与有机染料多层复合膜电致发光颜色的直流电压调制马於光，薛善华，黄劲松，田文晶，刘式墉，沈家骢，刘晓冬（吉林大学分子光谱与分子结构开放实验室，集成光电子学国家重点实验室，长春，１３００２３）（白求恩医科大学，长春，１３００２３）关键词聚合物，发光...     

p型结构的高效有机白光器件

制备了一种高效的p型结构的红光有机发光器件.对比发现这种p型结构的器件在亮度、电流密度以及效率等方面都优于普通的器件.将这种p型结构应用到白光器件上,使用红、绿、蓝三种发光材料作为发光层,通过调节它们各自的发射强度来实现白光发射.优化条件后,制得白光器件的最大电流效率和功率效率分别为19.3cd.A-1和12.1lm.W-1,最大亮度可达到31770cd.m-2,在5到11V驱动电压范围内为较纯正的白光,器件的可重复性好.     

Narrowband Pure Near-Infrared (NIR) Ir(III) Complexes for Solution-Processed Organic Light-Emitting Diode (OLED) with External Quantum Efficiency Over 16 %

Highly efficient near-infrared (NIR) emitters have significant applications in medical and optoelectronic fields, but the development stays a great challenge due to the energy gap law. Here, we report two NIR phosphorescent Ir(III) complexes which display emission peaks around 730 nm with a narrow full width at half maximum of only 43 nm. Therefore, pure NIR luminescence can be obtained without having a very long emission wavelength, thus alleviating the restriction of the energy gap law, and obtaining impressively high photoluminescence quantum yield up to 0.70. More importantly, the pure NIR organic light-emitting diode (OLED) fabricated by the solution-processed mothed shows outstanding device performance with the highest external quantum efficiency of 16.43 %, which sets a new record for solution-processed NIR-OLEDs based on different emitters. This work sheds light on the development of Ir(III) complexes with narrowband emissions as highly efficient pure NIR-emitters.     

超薄层在白色有机电致发光器件中的应用

以DCJTB为掺杂剂, 以BCP为空穴阻挡层, 研究了两种结构的有机电致发光器件ITO/NPB/BCP/Alq3:DCJTB/Alq3/Al(结构A)和ITO/NPB/BCP/Alq3/Alq3:DCJTB/Alq3/Al(结构B)的电致发光光谱. 实验结果显示, 在结构A器件的电致发光光谱中, 绿光的相对发光强度较弱,增加Alq3层的厚度对绿光的相对发光强度的影响也很小; 而在结构B器件的电致发光光谱中, BCP层与掺杂层(Alq3:DCJTB)之间的Alq3薄层对绿光的相对发光强度影响显著, 用很薄的Alq3层就可以得到强的绿光发射. 进一步改变器件结构, 利用有机超薄层就可以得到稳定的白光器件ITO/NPB(50 nm)/BCP(3 nm)/Alq3(3 nm)/Alq3:DCJTB(1%(w))(5 nm)/Alq3(7 nm)/Al. 随着电压的增加(14-18 V), 该器件的色坐标基本保持在(0.33, 0.37)处不动; 在432 mA·cm-2的电流密度下, 该器件的发光亮度可达11521 cd·m-2.     

A newly-designed self-powered electrochromic window

By converting incident light into electric power, self-powered electrochromic window (SP-ECW) can achieve color change in electrochromic layer with no need for external voltage. In this work, a newly-designed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light. The device consists of a working electrode with planar integration of photovoltaic (PV) and electrochromic (EC) elements on one electrode, a platinum counter electrode and a redox electrolyte comprising Br^–/Br ₃ ^– couple. A high transmittance modulation of 41% at 582 nm is obtained. Electrical energy converted from light is not only sufficient to drive the device, but also can be outputted to the external circuit.     

紫外臭氧处理增强溶液法MoO3薄膜的空穴注入能力

空穴注入层对有机发光二极管的性能有重要的影响,尤其是当器件中的空穴传输材料的最高占据分子轨道能级较深的时候。近年来有许多关于新型的溶液法空穴注入材料的研究。在本文中,我们对溶液法MoO₃薄膜使用了三种不同的处理方法来研究其对空穴注入性能的影响,即：在空气中150 ℃退火;在空气中150 ℃退火再紫外臭氧处理(UVO) 15 min;只进行UVO处理15 min。结果发现当MoO₃薄膜在空气中150 ℃退火后,器件的电流最小,空穴注入能力最差。而当MoO₃薄膜经过UVO处理后,器件的电流显著增大,工作电压大幅下降,器件性能接近于蒸镀的MoO₃薄膜的器件。更惊喜的是,这种改善在MoO₃薄膜仅作UVO处理后也可获得。经定量计算发现MoO₃薄膜经过UVO处理后的空穴注入效率能提高到约0.1。XPS分析表明通过UVO处理后,MoO₃薄膜中Mo⁵⁺成分减少并且薄膜表面的富氧吸附物被有效地消除,使得其化学计量基本与蒸镀的MoO₃薄膜相同。基于这种经UVO处理的溶液法MoO₃作为空穴注入层,器件的最大电流效率可达到48.3 cd∙A⁻¹。     

四[4,4'-双(4",4",4"-三氟代-1",3"-二氧代丁基)邻三联苯]双核铕配合物的发光及其在发光二极管中的应用

合成了一个双核铕的配合物,[HN(CH3CH2)3]2[Eu2(bdb)4]·CH3CH2OH,{H2bdb=4,4'-双(4",4",4"-三氟代-1",3"-二氧代丁基)邻三联苯}.该配合物在紫外和近紫外光激发下发出铕离子特征红光.配合物中三价铕离子的5D0激发态寿命为704μs,寿命曲线很好地和单指数衰减拟合曲线相吻合.监控614nm的红光发射,激发光谱位于250～420nm范围.在395nm处具有很强的激发强度,该配合物能够被395nm发射的InGaN芯片发出的近紫外光激发而发红光.变温光致发光测定表明,该配合物的温度淬灭效应很小.当温度升高到200℃,依然发射出很强的红光.配合物热稳定性达到260℃.发光性质和热稳定性满足制备LED器件的要求.将该配合物与395nm发射的InGaN芯片组合制备了红色发光二极管,当配合物和硅树脂的质量比为1:20,工作电流为20mA时,红色发光二极管的色坐标为x=0.61,y=0.31,发光效率为3.64lm/W.将该配合物与发蓝绿光的二-2-(2'-羟基苯基)苯并噻唑锌混合涂布在395nm发射的InGaN芯片上制备成了白光发光二极管,合适的质量比为铕配合物:锌配合物:硅树脂=1:1:25.工作电流为20mA时,色坐标x=0.32,y=0.32;色温Tc=6026K;显色指数Ra=81;发光效率为1.26lm/W.结果表明,该配合物是制备半导体高显色指数白光LED的一种红光材料.     

White and Red Organic Light Emitting Materials

Derivatives of 2,3-(1,4-dialkoxyaceno)norbornadiene underwent ring-opening metathesis polymerization (ROMP) upon the catalysis of a ruthenium complex to afford the corresponding polymers. The polymeric materials containing anthracene chromophores emit white electro-luminescence, which can be fabricated into light-emitting diodes (LED). The broad emission band is composed of a blue emission from anthracene and a red emission from aggregates. A single layer device, ITO/polymer/Ca/Al, can be turned on at 7V and exhibits maximum intensity 427 cd/m2 at 15 V. A double layer device, ITO/polymer/TPBI/Mg:Ag (TPBI = (2,2′,2"-(1,3,5-benzenetriyl)-tris(1-phenyl-1H-benzimidazole)) displayed blue light with turn-on voltage 6 V and maximal intensity 930 cd/m2 at 15 V.Derivatives of bisindolylmaleimide were found to form amorphous solid films which exhibit intensive red luminescence. The property of forming glasses can be ascribed to the nonplanar geometry of these molecules. LED devices were fabricated by a layer of pure dye sandwiched between two charge transporting films. The yellow emission spectrum of the devices utilizing Alq (tris(8-hydoxyquinolinato)aluminum) contains a green component from Alq. Pure red emissions can be achieved by replacing Alq with TPBI. Typical devices can be turned on at ～3 V with maximal intensity 2000 cd/m2. White color devices are under current investigation, in which the green Alq layer is replaced by its blue derivative (bis(2-methyl-8-hydoxyquinolinato)(phenolato)aluminum).     

Electroluminescent properties of a partially‐conjugated hyperbranched poly(p‐phenylene vinylene)

In this paper, the electroluminescent properties of a new partially‐conjugated hyperbranched poly (p‐phenylene vinylene) (HPPV) were studied. The single layer light‐emitting device with HPPV as the emitting layer emits blue‐green light at 496 nm, with a luminance of 160 cd/m² at 9 V, a turn‐on voltage of 4.3 V and an electroluminescent efficiency of 0.028 cd/A. By doping an electron‐transport material [2‐(4‐biphenylyl)‐5‐phenyl‐1,3,4‐oxadiazole, PBD] into the emitting layer and inserting a thin layer of tris(8‐hydroxy‐quinoline)aluminum (Alq₃) as electron transporting/hole blocking layer for the devices, the electroluminescent efficiency of 1.42 cd/A and luminance of 1700 cd/m² were achieved. The results demonstrate that the devices with the hyperbranched polymers as emitting material can achieve high efficiency through optimization of device structures. Copyright © 2006 John Wiley & Sons, Ltd.     

一类窄带隙芴基共聚物的合成及其在发光二极管和太阳电池中的应用

基于9,9-二辛基芴(DOF)与窄带隙单体2,3-二甲基-5,8-二噻吩-喹喔啉(DDQ),通过Suzuki偶合反应,合成了一系列无规和交替窄带隙的芴基共聚物(PFO-DDQ),并对它们的紫外-可见吸收光谱、光致发光光谱、电致发光性能和光伏性能进行了初步研究.共聚物在380 nm和490 nm处有两处明显的吸收峰,其中490nm处的吸收强度随着共聚物中窄带隙单元(DDQ)含量的增加而成比例加强.随着共聚物中窄带隙单元(DDQ)含量的增加,电致发光峰值从580 nm红移到了635 nm.基于该类材料的橙红或饱和红色发光二极管最大外量子效率为1.33%,流明效率为1.54 Cd/A.试验中观察到了窄带隙单元的能量陷阱机制.以窄带隙单元含量为30%的聚合物(PFO-DDQ30)为电子给体、PCBM为电子受体所制备的共混体相异质结太阳电池最大能量转换效率为1.18%,开路电压0.9 V,短路电流密度2.66 mA/cm2.光敏曲线覆盖300 nm~700 nm.     

不同电子传输层的蓝光有机电致发光器件的性能研究

自从Tang等^[1]首次报道多层有机电致发光器件（OLED）以来,其在亮度和效率上有了质的飞跃,表明器件的结构对提高发光亮度和发光效率起着至关重要的作用,单层器件虽然具有制作简单的优点,但却存在明显缺点：（1）复合发光区靠近金属电极,该处缺陷很多,非辐射复合几率大,导致器件效率降低;（2）由于两种载流子注入不平衡,载流子的复合几率较低,因而影响器件的发光效率,要使发光层中具有高的载流子辐射复合效率,两种载流子的注入及传输能力应相当,否则传输快的一方就会直接穿过发光层到达对电极被猝灭,平衡电子和空穴的注入与传输可通过在电极和发光层之间加入载流子输运层或限制层制作多层器件的途径来实现,基于上述考虑,我们以PPCP为发光层（PPCP是一种荧光效率较高的蓝光材料^[2-4],对其进行深入研究尚未见有文献报道＿,设计了4种不同电子传输层（ETL)的三层 结构的OLED,为研究电子传输层对器件性能的影响,我们还制备了不含电子传输层的双层器件,结果表明,通过选择合适的ETL,OLED的发光亮度及发光效率会有很大程度的改善。     

New ladder‐type conjugated polymer containing carbazole and fluorene units in backbone: Synthesis,optical, and electrochemistry properties

This article describes the synthesis and characterization of a new ladder‐type poly (p‐phenylene) (LPFC) containing alkylcarbazole and dialkylfluorene units in backbone, and its optical and electrochemical properties as well as its light‐emitting device performance. LPFC shows the well‐defined structure, high molecular weights, excellent thermal stability, and good solubility in common organic solvents. And it also shows strongly blue emission (λ_max = 465 nm) with quantum efficiency of 70% in solution, while its solid emission (λ_max = 470 nm) is almost the same as its solution. Electrochemical studies show that the highest occupied molecular orbital (HOMO) energy levels of LPFC is up to 5.29 eV, which is significantly higher than that of LPPP without carbazole in backbone, indicating an enhanced ability of hole injection from anodes. Furthermore, the single layer light‐emitting device using LPFC as the active layer shows blue emission (λ_max = 470 nm) with maximum luminescence of ～ 2000 cd/m² and maximum luminance efficiency of 0.43 cd/A. The attractive properties exhibited from new ladder‐type polymer establish LPFC as a good candidate for the potential application as transporting and emitting layer in polymeric light emitting diodes. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3120–3127, 2008     

Photovoltaic devices based on palladium(II) <Emphasis Type="Italic">meso</Emphasis>-tetra(benzo-15-crown-5)porphyrinate

The properties of photovoltaic cells containing an MEH-PPV composition with palladium(II) meso-tetra(benzo-15-crown-5)porphyrinate as an electron-conduction layer and copper(II) phthalocyanine as a hole transport layer were studied. The influence of the environment and a top-electrode metal on the operation efficiency was also examined. It was found that oxygen at the fabrication steps affects in different manners the formation of open-circuit voltage and the performance of the device. A certain correlation between the properties of electrodes and the photoelectromotive force was established. The highest conversion efficiency of 0.02 electrons per incident photon was obtained for samples that additionally contained an amorphous selenium layer applied over the aforementioned conducting layers.     

Tunable full-color emission of two-unit stacked organic light emitting diodes with dual-metal intermediate electrode

The color-tunable stacked organic light-emitting devices (SOLEDs) with independently-addressable intermediate Al/Au electrode are examined. High brightness color-tunable SOLED can be achieved by properly optimizing the Al/Au electrode and using appropriate electron- and hole-injection layer. Full-color emission is achieved in a simple device structure with features of (1) only two-unit SOLED, and (2) the intermediate electrode is the Al/Au dual metal layers which are easy to process and have no damage to the organic layer.     

吡唑啉衍生物作为空穴传输层在电致发光材料中的应用

我们曾报道过有关1,3二苯基吡唑啉衍生物的光谱和光物理行为^[1,2],并详细地研究了它们在受激发后的辐射和非辐射衰变过程.该类化合物作为一种良好的光致发光材料,由于存在着分子内共轭的电荷转移结构,因此表现出较强的光诱导分子极化能力,可用作为有机非线性光学材料^[3]、光折变材料等.此外,还发现该类化合物在组合型光导器件中可用作空穴传输层材料.既然这类化合物兼具光致发光和空穴传输功能,很自然的会考虑到,它是否也能用作为一种有机的电致发光(EL)材料.有机电致发光材料的重要性自不待言,特别近年来许多科学家致力于此,因此进展很快.但寻找新的高效材料,不论是用作主要的发光层或其它的辅助性化合物,仍在继续.本简报即是对上述化合物用作EL材料的初步研究.     

基于双极性小分子的单层非掺杂红色荧光有机发光二极管(英文)

以双极性小分子4,9-二(4-(2,2-二苯乙烯基)苯基)萘并[2,3-c][1,2,5]噻二唑(BDPNTD)为发光层,制备得到了单层非掺杂红色荧光有机发光二极管.通过在阳极ITO与有机层BDPNTD之间插入1nm厚的WO3或MoO3薄膜,获得了单层有机发光二极管:起亮电压为2.4V,最大发光亮度为4950cd·m-2,发光波长为636nm,CIE坐标约为(0.65,0.35).这证明了作为修饰层的WO3或MoO3薄膜可以改进ITO/BDPNTD界面的空穴注入,进而在器件中实现空穴与电子的平衡.     

Multiple-quantum-well perovskite for hole-transport-layer-free light-emitting diodes

We demonstrate hole-transport-layer-free light-emitting diodes(LEDs) based on solution-processed multiple-quantum-well(MQW) perovskite. The MQW perovskite can self-assemble to a unique structure of vertically graded distribution with two-dimensional layered perovskite covered by three-dimensionallike perovskite at top, which can naturally form a barrier of electron transporting to the anode interface,thereby enhancing the charge capture efficiency. This leads to hole-transport-layer-free MQW per...     

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.     

Organic Light Emitting Diodes with Lithium Contained Alq3 as Electron Injection Layer

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｏｒｇａｎｉｃｌｉｇｈｔｅｍｉｔｔｉｎｇｄｉｏｄｅ(ＯＬＥＤ) ,ｓｏｍｅｍｅｔａｌｓｗｉｔｈｌｏｗｗｏｒｋｆｕｎｃｔｉｏｎ ,ｓｕｃｈａｓａｌｌｏｙｏｆｍａｇ ｎｅｓｉｕｍａｎｄｓｉｌｖｅｒ(Ｍｇ∶Ａｇ) [1] ａｎｄａｌｕｍｉｎｉｕｍ[2 ] ,ａｒｅｕｓｅｄａｓｔｈｅｅｌｅｃｔｒｏｎｉｎｊｅｃｔｉｏｎｃａｔｈｏｄｅｓ .ＩｎＭｇ∶Ａｇａｌ ｌｏｙｓｉｌｖｅｒｉｓｕｓｅｄｔｏｐｒｏｔｅｃｔｍａｇｎｅｓｉｕｍｆｒｏｍｔｈｅｒｅａｃ ｔｉｏｎｏｆｍａｇｎｅｓｉｕｍｗｉｔｈｏｘｙｇｅｎａｎｄ…