铱配合物为核、聚对苯为枝的超支化电磷光聚合物的合成与发光性能

用Suzuki缩聚反应合成了以三-(2-间溴苯基吡啶)合铱为核,以聚2,5-二辛氧基苯为枝的超支化电磷光绿光聚合物（PPPIrppy）。 聚合物中当铱配合物摩尔分数大于0.5%时,主体的发射被完全淬灭,电致发光（EL）光谱只有位于520 nm处的绿光发射,表明主客体之间发生了有效的能量转移。 基于铱配合物摩尔分数为1％的聚合物的发光器件(器件结构：ITO/PEDOT:PSS/emissive layer/Ba/Al)在电流密度为40×10-3 A/cm2时,最大电流效率达到2.89 cd/A,器件的最大亮度达到1 689 cd/m2,色坐标为（0.34,0.59）。     

新型红光电磷光芴-alt-咔唑共聚物的合成与发光性能

通过Suzuki聚合反应合成了一系列以芴-alt-咔唑为主链, 铱配合物为侧链的深红色电磷光共轭聚合物. 发光器件结构为ITO/PEDOT∶PSS/PVK/Copolymer/Ba/Al, 基于共聚物PFCzIrNiq-1的器件在电流密度为9.4 mA/cm2时, 最大外量子效率为0.23%, 最大发射波长为680 nm.     

新型电磷光咔唑-co-吡啶共聚物的合成与发光性能

用Suzuki缩聚反应制备了一系列新型咔唑-吡啶共轭主链上含有金属铱配合物单元的共聚物. 共聚物发光器件结构为ITO/PEDOT:PSS/polymer＋PBD (w＝30%)/CsF/Al [氧化铟锡/苯磺酸掺杂聚乙烯基二氧噻吩/聚合物＋2,4-二苯-5-4-叔丁基苯-1,3,4-恶二唑(w＝30%)/氟化铯/铝]. 基于共聚物PCzPyIrMppy2的器件在电流密度为20.8 mA/cm2时, 最大外量子效率和流明效率分别达到4.1%和6.1 cd/A. 在电流密度200 mA/cm2时, 器件的最大外量子效率和流明效率仍分别达到3.2%和4.8 cd/A, 器件的发光的最大波长位于570 nm, 最大亮度达到13251 cd/m2. 研究结果表明, 在共轭聚合物主链上引入螯合金属铱配合单元是实现高效、稳定的电致磷光器件的有效方法之一.     

掺杂meso-四(对葵酰氧基苯基)卟啉铂的饱和红色聚合物发光器件

在聚2,7-(9,9-二辛基)芴(PFO)和30%的2-(对联苯基)-5-(对叔丁基苯基)-1,3,4-噁二唑(PBD)主体材料中掺杂短磷光寿命的meso-四(对正葵酰氧基苯基)卟啉铂（TDPPPt）,制成聚合物基发光器件。 器件结构为：ITO/PEDOT∶PSS/PVK/PFO+30%PBD∶TDPPPt/Ca/Al（ITO:氧化铟锡;PEDOT:聚3,4-乙撑二氧噻吩;PSS：聚苯乙烯磺酸盐;PVK：聚乙烯基咔唑）。 当客体掺杂浓度≥3%时,器件给出饱和的红色发射。 当驱动电压从7 V升高至14 V时,器件发光色度保持不变,CIE(国际发光照明委员会)色坐标稳定在(0.66,0.28）左右。 器件的最大亮度和电流效率分别为1.390 cd/m2和1.34 cd/A。 在电流密度100×10-3和150×10-3 A/cm2时,电流效率分别为1.18和0.99 cd/A,器件在高电流密度下具有良好的稳定性。     

基于不同辅助配体螯合电磷光聚合物的合成与性能研究

通过A-A, B-B型的Suzuki缩聚反应将三个具有不同辅助配体的2-(2'-苯并[b]噻吩)吡啶(btp)双环铱金属配合物引入芴和咔唑交替共聚物(PFCz)的主链上, 合成一系列最大发光波长在660 nm的红光螯合电磷光聚合物, 并研究了它们的电致发光性能. 实验证明了在这类电磷光聚合物中配合物单元辅助配体合理的分子设计, 可以提高配合物单体的溶解度, 提高聚合物的分子量和发光性能. 通过优化器件结构, 聚合物PFBtpIrf5单层器件(ITO/PEDOT:PSS/polymer＋PBD(30 wt%)/Ba/Al)的性能最好: 在电流密度为14.3 mA/cm²时, 最大外量子效率为1.93%.     

新型超支化聚(芴-co-吡啶并[3,2-b]吡嗪)共聚物的合成与发光性能

合成了新型三溴代的含有吡啶并[3,2-b]吡嗪的化合物, 通过Suzuki缩聚反应合成了以吡啶并[3,2-b]吡嗪为核, 以9,9-二辛基芴为枝的超支化共聚物. 该共聚物在甲苯和四氢呋喃等有机溶剂中具有较好的溶解性能. 采用共聚物制备了结构为ITO/PEDOT/polymer/Ca/Al的发光器件, 其中基于共聚物PFPQ-2的器件在电流密度为3.8 mA/cm²时得到蓝光发射, 最大外量子效率为1.29%, 最大亮度为1173 cd/m², 色坐标为(0.16, 0.11).     

二-[2',6'-二氟-2,3'-联吡啶- N,C4'][2,4-戊二酮-O,O]铱(III)的合成及其光致和电致发光性能

以2',6'-二氟-2,3'-联吡啶(Hdfpypy)为主配体,乙酰丙酮为辅助配体,合成了二-[2',6'-二氟-2,3'-联吡啶-N,C4'][2,4-戊二酮-O,O]铱(Ⅲ)配合物((dfpypy)2Ir(acac))。在THF溶液中,该配合物溶液最大光致发光光谱为465 nm(半峰宽为53 nm),同时伴有490 nm的肩峰,与面式-Ir(dfpypy)3在438和463 nm两个强度相近的发光光谱相比,发生了红移。配合物在脱气四氢呋喃溶液中的PL量子效率为0.41。将(dfpypy)2Ir(acac)以不同的浓度掺杂在主体材料聚乙烯基咔唑(PVK)中,制备了器件结构为:ITO/PEDOT∶PSS(聚二氧乙基噻吩∶聚对苯乙烯磺酸)/PVK∶(dfpypy)2Ir(acac)(100∶x)(70 nm)/Ba/Al的蓝色聚合物发光器件(x代表掺杂量)。在驱动电压为15.4 V时,2%掺杂器件的最大发光亮度为1400 cd/m2。当电流密度为0.23×10-3A/cm2时,2%掺杂器件最大亮度效率(ηc)为1.6 cd/A。器件的色坐标(CIE)值为(0.15,0.27)。     

含1,1-二（4-（N,N-二甲基胺基）苯基）-2,3,4,5-四苯基噻咯的聚合物在三种阴极结构中的电致发光性能

设计合成了一种1,1-位为二（4-（N,N-二甲基胺基）苯基的新型噻咯单体,并与2,7-芴单体聚合得到六苯基噻咯单体投料量为1%、10%、20%的三种共聚物PF-N-HPS1～20.研究了这些共聚物的紫外吸收光谱、电化学性质、光致发光光谱和电致发光性能.PF-N-HPS的HOMO能级为5.25～5.58eV,呈现绿光发射.以PF-N-HPS为发光层,制作了三种聚合物发光二极管（器件结构A：ITO/PEDOT/PF-N-HPS/Al;器件结构B：ITO/PEDOT/PF-N-HPS/Ba/Al;器件结构C：ITO/PEDOT/PF-N-HPS/TPBI/Ba/Al）.其中器件结构A的电致发光效率仅为0.1～0.33cd/A,说明PF-N-HPS中的4-（N,N-二甲基胺基）苯基结构不能使单独的Al阴极实现良好的电子注入.采用了低功函金属Ba阴极的器件结构B能改善电子的注入,使电致发光效率提高到0.85～1.44cd/A.器件结构C采用TPBI（HOMO：6.2eV）作为电子传输和空穴阻挡层,促进了电子和空穴的有效复合,进一步提高了电致发光效率（4.56～7.96cd/A）,其中TPBI层将噻咯聚合物与金属阴极隔离可能减少发光层在阴极界面处的激子猝灭也起到了一定的作用,器件结构C较器件结构B还获得了更好的绿光光谱.     

导电聚合物有序超薄膜的合成及其作为有机电致发光器件空穴注入层

采用修饰多层LB膜的方法制备了导电聚合物聚-3,4-乙烯二氧噻吩/二十烷酸(PEDOT:AA)复合层状有序膜, 构筑了一种导电聚合物镶嵌的多层有序膜结构. 将这种导电聚合物有序薄膜沉积于ITO电极表面, 将其作为有机电致发光二极管(OLED)的空穴注入层, 并研究了ITO/(PEDOT:AA)/MEH-PPV/Al器件的性能. 研究结果表明, 与采用聚3,4-乙烯二氧噻吩/聚苯乙烯磺酸(PEDOT:PSS)自组装膜和旋涂膜作为空穴注入层的ITO/(PEDOT:PSS)/MEH-PPV/Al器件相比, 器件的发光效率增加, 起亮电压降低. 我们认为这是由于PEDOT:AA薄膜提供了一种有序层状结构后, 减小了ITO与MEH-PPV间的接触势垒, 改善了空穴载流子注入效率. 进一步的研究表明, 由于PEDOT:AA多层膜间靠较弱的亲水、疏水作用结合, 这种导电多层有序膜的热稳定性与普通LB膜相似, 在较高温度下发生从层状有序态到无序态的变化, 这是导致OLED器件性能发生劣化的主要原因.     

一种含咔唑基哒嗪的新型金属铱电致磷光材料的合成与性能研究

合成了一种新型的以咔唑基哒嗪为配体的环金属化铱配合物Ir(pcpd)2(acac)(其中pcpd=3-(9-苯基-3-咔唑基)-6-甲基哒嗪,acac为乙酰丙酮),并以其作为发光体,制备了有机电致发光器件.其中结构为ITO/HIL001/HTL001/CBP:Ir(pcpd)2acac(12.3%)/TPBi/AlQ/LiF/Al的器件最大发光亮度19656cd/m2,最大效率14cd/A,发光峰值580nm.器件表征结果显示该配合物具有强磷光发光特性.     

Synthesis and characterization of polyfluorenes containing bisphenazine units

Novel conjugated copolymers based on 9,9‐dioctylfluorene and bisphenazine (BP) were synthesized by Suzuki polymerization. Energy transfer from the conjugated main chain to the BP moieties was observed. Full energy transfer was achieved when the molar content of the bisphenazine was 20% (20BPPF) in toluene solution. The similar phenomena were observed even for 1% bisphenazine content copolymer (1BPPF) in film. The lowest occupied molecular orbital (LUMO) energy levels (?3.06 eV) of the copolymers were lower than that of the polyfluorene homopolymer (PFO; ?2.65 eV), indicating that the introduction of the BP unit was benefit to electron injection. Single‐layer electroluminescent devices (ITO/PEDOT:PSS/polymer/LiF/Al) were fabricated to investigate their electroluminescence (EL) performances. The maximum brightness and current efficiency of all BPPF copolymers surpassed the PFO homopolymer. The best single‐layer device was based on 5BPPF, with a maximum brightness of 1532 cd/m² and current efficiency of 1.09 cd/A. Much higher efficiency could be achieved for multilayer EL devices of 5BPPF (ITO/PEDOT:PSS/PVK/polymer/TPBI/LiF/Al), which showed a maximum current efficiency of 10.01 cd/A. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1990–1999, 2010     

Carbazole compounds as host materials for triplet emitters in organic light-emitting diodes: polymer hosts for high-efficiency light-emitting diodes

A carbazole homopolymer and carbazole copolymers based on 9,9'-dialkyl-[3,3']-bicarbazolyl, 2,5-diphenyl-[1,3,4]-oxadiazole and 9,9-bis(4-[3,7-dimethyloctyloxy]phenyl)fluorene were synthesized and their electrical and photophysical properties were characterized with respect to their application as host in phosphorescent polymer light-emitting diodes. It is shown that the triplet energy of a polymer depends on the specific connections between its building blocks. Without changing the composition of the polymer, its triplet energy can be increased from 2.3 to 2.6 eV by changing the way in which the different building blocks are coupled together. For poly(9-vinylcarbazole) (PVK), a carbazole polymer often used as host for high-energy triplet emitters in polymer light-emitting diodes, a large hole-injection barrier of about 1 eV exists due to the low-lying HOMO level of PVK. For all carbazole polymers presented here, the HOMO levels are much closer to the Fermi level of a commonly used anode such as ITO and/or a commonly used hole-injection layer such as PEDOT:PSS. This makes high current densities and consequently high luminance levels possible at moderate applied voltages in polymer light-emitting diodes. A double-layer polymer light-emitting diode is constructed comprising a PEDOT:PSS layer as hole-injection layer and a carbazole-oxadiazole copolymer doped with a green triplet emitter as emissive layer that shows an efficacy of 23 cd/A independent of current density and light output.     

Synthesis,characterization, and electroluminescence of novel copolyfluorenes and their applications in white light emission

New copolyfluorenes (PC8OF0–PC8OF50) comprised of 9,9‐dioctylfluorene and jacketed units 2,5‐bis[(5‐octyloxy‐phenyl)‐1,3,4‐ oxadiazole]‐1‐(3,5‐dibromophenyl)‐benzene (35C8) were synthesized by palladium‐catalyzed Suzuki coupling reaction. They were characterized by molecular weight determination, ¹H NMR, elemental analysis, DSC, TGA, absorption and emission spectroscopy, and cyclic voltammetry (CV). These copolymers were readily soluble in common organic solvents and exhibited high glass transition temperature and thermal stability.The copolymer films showed absorption peaks from 381 nm to 351 nm, and PL peaks from 432 nm to 421 nm with a blue shift originated from 35C8 units. Both the HOMO energy levels and LUMO levels changed little as the content of 35C8 units increased (?5.59 eV to ?5.48 eV and ?2.60 eV to ?2.49 eV). Electroluminescent devices: ITO/PEDOT:PSS[poly(ethylenedioxythiophene):polystyrenesulfonate]/polymer/Ca (25 nm)/Ag(80 nm) (a), ITO/PEDOT:PSS/polymer/TPBI [1,3,5‐ tris(N‐phenylbenzimidazol‐2‐yl)benzene](15 nm)/Mg:Ag(10:1, wt)/Ag (b), and ITO/ PEDOT:PSS/PVK[Poly(N‐vinylcarbazole)]/polymer/TPBI(15 nm)/Ca(25 nm)/Ag(80 nm) (c) were fabricated to investigate the influence of jacketed contents and device architectures on emission characteristics. The maximum brightness and current efficiency of the PC8OF25 device (5097.8 cd/m² and 0.484 cd/A) surpassed those of the PC8OF0 device (3122.8 cd/m² and 0.416 cd/A). The EL emissions of PC8OF0 – PC8OF50 were pure blue and low‐energy excimer emission bands were successfully suppressed, indicating that these copolymers could be good candidates for blue light‐emitting materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4555–4565, 2009     

Fluorene‐based alternating polymers containing electron‐withdrawing bithiazole units: Preparation and device applications

We report here the synthesis via Suzuki polymerization of two novel alternating polymers containing 9,9‐dioctylfluorene and electron‐withdrawing 4,4′‐dihexyl‐2,2′‐bithiazole moieties, poly[(4,4′‐dihexyl‐2,2′‐bithiazole‐5,5′‐diyl)‐alt‐(9,9‐dioctylfluorene‐2,7‐diyl)] (PHBTzF) and poly[(5,5′‐bis(2″‐thienyl)‐4,4′‐dihexyl‐2,2′‐bithiazole‐5″,5″‐diyl)‐alt‐(9,9‐dioctylfluorene‐2,7‐diyl)] (PTHBTzTF), and their application to electronic devices. The ultraviolet–visible absorption maxima of films of PHBTzF and PTHBTzTF were 413 and 471 nm, respectively, and the photoluminescence maxima were 513 and 590 nm, respectively. Cyclic voltammetry experiment showed an improvement in the n‐doping stability of the polymers and a reduction of their lowest unoccupied molecular orbital energy levels as a result of bithiazole in the polymers' main chain. The highest occupied molecular orbital energy levels of the polymers were ?5.85 eV for PHBTzF and ?5.53 eV for PTHBTzTF. Conventional polymeric light‐emitting‐diode devices were fabricated in the ITO/PEDOT:PSS/polymer/Ca/Al configuration [where ITO is indium tin oxide and PEDOT:PSS is poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonic acid)] with the two polymers as emitting layers. The PHBTzF device exhibited a maximum luminance of 210 cd/m² and a turn‐on voltage of 9.4 V, whereas the PTHBTzTF device exhibited a maximum luminance of 1840 cd/m² and a turn‐on voltage of 5.4 V. In addition, a preliminary organic solar‐cell device with the ITO/PEDOT:PSS/(PTHBTzTF + C₆₀)/Ca/Al configuration (where C₆₀ is fullerene) was also fabricated. Under 100 mW/cm² of air mass 1.5 white‐light illumination, the device produced an open‐circuit voltage of 0.76 V and a short‐circuit current of 1.70 mA/cm². The fill factor of the device was 0.40, and the power conversion efficiency was 0.52%. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1845–1857, 2005     

Conjugated copolymers comprised cyanophenyl‐substituted spirobifluorene and tricarbazole‐triphenylamine repeat units for blue‐light‐emitting diodes

A series of conjugated blue‐light‐emitting copolymers, PTC‐1 , PTC‐2 , and PTC‐3, comprised different ratios of electron‐withdrawing segments (spirobifluorene substituted with cyanophenyl groups) and electron‐donating segments (tricarbazole‐triphenylamines), has been synthesized. The structures of these polymers were characterized and their thermal, photophysical, electrochemical, and electroluminescence properties were measured. Incorporation of rigid spirobifluorene units into the copolymers led to blue‐shifted absorption peaks in dilute toluene solution. Cyclic voltammetric measurement indicated the bandgaps of the polymers were in the range of 2.77–2.94 eV. It was found that increasing cyanophenyl‐spirobifluorene content in the polymer backbone lowered both the HOMO and LUMO energy levels of the copolymers, which was beneficial for electron injection/transporting in the polymer layer of the device. OLED device evaluation indicated that all the polymers emitted sky blue to deep blue light when the pure polymers were used as the emissive layers in the devices with a configuration of ITO/PEDOT:PSS/polymers/CsF/Ca/Al. The devices have been optimized by doping 30 wt % PBD into the polymer layers. Among the doped devices, PTC‐2 showed the best performance with the turn‐on voltage of 3.0 V, maximum brightness of 7257 cd/m², maximum current efficiency of 1.76 cd/A, and CIE coordinates of (0.15, 0.14). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 292–301, 2010