抗菌医药左氧氟沙星在有机电致发光二极管中的应用

左氧氟沙星(LOFX)是一种知名的抗菌药物, 它的价格非常便宜, 且有成熟的合成和纯化技术. 本文中首次将LOFX作为一种蓝光发光材料和电子传输材料应用于有机电致发光器件(OLED)中. 通过热重分析、UVVis吸收光谱、发射光谱以及循环伏安曲线详细地表征了LOFX的热学及光物理特性. LOFX有高的分解温度,为327 ℃; HOMO、LUMO能级分别为-6.2 和-3.2 eV, 光学带隙为3.0 eV. 以LOFX作为客体材料, 掺杂在主体材料4,4'-二(9-咔唑)联苯(CBP)中制备了蓝光OLED, 该器件的电致发光(EL)发射峰位于452 nm, 最大亮度为2315 cd·m^-2. 进一步, 选择8-羟基喹啉铝(Alq₃)作为参考材料, 分别以LOFX和Alq₃作为电子传输材料制备了结构相同的单载流子器件和绿色磷光OLED. 在相同的电压下, 以LOFX作为电子传输材料的单载流子器件的电流密度比以Alq₃作为电子传输材料的单载流子器件更高. 同时, 以LOFX作为电子传输材料的绿色磷光OLED获得更高的器件效率. 从这些EL性能可以看出, LOFX同时也是一很好的电子传输材料.     

小分子蓝色磷光主体材料

有机电致发光器件是有机光电子领域的研究热点,在平板显示和固体照明领域有着广阔的应用前景.目前,由于器件效率和稳定性的问题,蓝色磷光器件是有机电致发光器件的瓶颈,而蓝色磷光主体材料的选择是影响蓝色磷光器件性能的关键因素.综述了小分子蓝色磷光主体材料的最新研究进展,重点介绍了各类小分子蓝色磷光主体材料的设计思想、器件性能.包括空穴传输性主体材料、含硅主体材料、电子传输性主体材料、双极主体材料和可湿法加工的蓝色磷光小分子主体材料的结构、特点及相应器件性能.最后对小分子蓝色磷光主体材料的发展方向进行了展望.     

高效蓝光有机电致磷光主体材料的研究进展

磷光有机发光二极管(PHOLEDs)相对于传统的荧光有机电致发光具有更高的量子效率, 在平板显示和固态照明方面有极大的应用前景. 本工作将近几年来外量子效率高于20%的蓝光PHOLEDs中小分子主体材料进行总结, 并按空穴传输型、电子传输型和双极传输型主体材料分类, 重点介绍这些材料的分子结构、三线态能级、HOMO/LUMO能级、热稳定性、形态稳定性以及作为蓝光PHOLEDs主体材料的器件性能, 以期对主体材料的研究及OLED产业化提供参考价值.     

铕配合物共掺杂电致发光器件效率滚降的延缓(英文)

将Alq3[tris(8-hydroxyquinoline)aluminium]和Eu(TTA)3phen(TTA=thenoyltrifluoroacetone,phen=1,10-phenanthroline)共掺杂进入主体材料CBP(4,4′-N,N′-dicarbazole-biphenyl)中,我们制作并研究了一系列电致发光器件。经过优化Alq3的掺杂浓度,在不改变色纯度的情况下,器件的效率滚降被大幅降低并获得了近乎加倍的最大亮度。发光层中的Alq3分子不仅促进了电子的注入和传输,还延缓了空穴的传输。借助电致发光光谱,我们证实Alq3分子作为阶梯加速空穴从CBP分子到Eu(TTA)3phen分子的迁移,从而促进了电子和空穴在Eu(TTA)3phen分子上的平衡。因此,我们认为器件的效率滚降受到抑制的原因有两点:一是复合区间的加宽,二是Eu(TTA)3phen分子上空穴和电子的分布更加平衡。     

基于联咔唑为骨架的双极主体材料的合成及其在有机电致发光器件中的应用

咔唑类衍生物具有良好的空穴传输性能和较高的三重态能级,在有机电致发光器件中一般用来构建空穴传输材料和主体材料。本文通过在联咔唑的3和6位引入具有电子传输能力的氰基,设计合成了一种以双咔唑二聚体为分子骨架的新型双极性有机电致发光主体材料6,6’-双氰基-9,9’-二苯基-3,3’-联咔唑（BCzDCN）,研究了其发光性能、热稳定性和电化学性质。低温磷光发射光谱测试表明BCzDCN的三重态能级高于传统的天蓝色磷光掺杂材料双（4,6-二氟苯基吡啶-N,C²’）吡啶甲酰合铱（FIrpic）。以BCzDCN为主体材料,FIrpic和双（4-苯并噻吩）[3,2-C]吡啶-N,C²’）乙酰丙酮合铱（PO-01）分别为蓝色和黄色磷光掺杂材料,制备了蓝色和白色有机磷光发光二极管器件。器件的最大电流效率分别达到34.6 cd/A和59.0 cd/A。并且在1000 cd/m²亮度下的效率滚降仅有4.1%和5.1%。     

磷光客体三重态能级对基于PVK主体的电致发光器件的影响

将磷光客体掺入PVK:PBD主体材料中是获得高效率磷光电致发光器件 (PhPLED)的有效途径.然而,分别掺杂Ir(pppy)₃、Ir(F-pppy)₃和Ir(F₂-pppy)₃三种磷光客体的PhPLED器件性能件却显著不同.我们分别模拟主-客体间能量转移和客体直接捕获电子空穴对两种机制,研究了三种客体材料的磷光发射及其衰减过程.研究表明:平衡的载流子注入和客体高效率的载流子捕获是实现Ir-配合物掺杂的PhPLED器件性能优良的主要机制,PVK较低的三重态能级使其无法成为蓝光磷光电致发光器件的主体,在PVK中掺入PBD的方法,则进一步降低了主体材料的三重态能级,这是蓝光磷光电致发光器件运行效率较低的主要原因.本文的研究结果可为高分子磷光电致发光器件的制备技术和新型磷光主体的设计提供参考.     

一种基于咔唑的新型磷光主体材料的合成及光电性能

设计并合成了一种基于咔唑的新型的磷光主体材料, 即9-(6-(9-咔唑基)己基)咔唑(hCP), 对其结构及性能进行了表征. 研究结果表明: hCP分子中两个咔唑与烷基链是非共平面的, 由于长烷基链的缠绕, 因而具有较高的三线态能级(3.01 eV)和较高的玻璃化温度(93℃); 以hCP为主体材料, 与绿光磷光染料三(2-苯基吡啶)合铱(Ir(ppy)₃)掺杂作为发光层, 制备了磷光电致发光器件, 其器件的最大电流效率为15.1 cd·A^-1, 相对于4,4'-N,N'-二咔唑基联苯(CBP)为主体材料的参考器件, 显著提高了34.8%.     

蓝色有机电致磷光主体材料

有机电致发光(OLEDs)因其具有驱动电压低、主动发光、亮度高、视角宽、响应快、耐冲击与震动等特点,在平板显示与照明领域有着广阔的应用前景。磷光有机电致发光二极管(PhOLEDs)由于能够同时利用三重态和单重态激子,内量子效率从理论上可达到100%,从而克服了传统荧光OLEDs只利用单重态激子时效率25%的限制,在过去的几十年里受到业内人士的极大关注。但要实现三重态磷光,通常需要将重金属原子与主体材料进行掺杂,而重金属配合物的磷光寿命相对较长,容易引起浓度猝灭和三重态-三重态湮灭,所以需要找到合适的主体材料与重金属的磷光发射体进行掺杂来减少上述因素的影响从而得到高性能的电致磷光器件。本文综述了近年来国内外蓝色有机电致磷光主体材料的研究状况,并对空穴传输型、电子传输型和双极传输型的蓝色磷光主体材料按照官能团的不同进行了分类总结和评述,并对其光物理性质、热学性质、电化学性质及器件性能等作了详细归纳比较,最后展望了蓝色有机电致磷光主体材料的前景和发展趋势。     

基于咔唑-三唑的新型主体材料及天蓝光有机电致磷光器件

本研究针对蓝光主体材料相对缺乏的现状,利用有机电致磷光器件高效率的优势,选择1,2,4-三唑为电子传输功能基团、咔唑为空穴传输功能基团,设计、制备了新型主体材料oCzTz。通过邻位取代方式实现了分子立体构型高度扭曲,从而使分子的三重态能量达到3.01eV;oCzTz具有较高的热分解温度(353℃)和玻璃化转变温度(110℃);量化计算显示,分子的前线轨道在咔唑和三唑基团之间高度分离。以oCzTz为主体、以FIrpic为发光客体的天蓝光电致磷光器件启亮电压为3.4V,电流效率和功率效率分别高达37.2cd·A-1和29.2lm·W-1,是以TPBI为电子传输层的同类器件的最高效率之一。     

基于香豆素衍生物的新型绿色/红色磷光有机电致发光主体材料的设计、合成及性能表征

设计并合成了一种新型的香豆素衍生物,3,3-’(1,3-苯基)双(7-乙氧基-4-甲基香豆素)(mEMCB),并系统地对该香豆素衍生物进行了结构表征、光物理性能、热物理性能及电化学性能的研究.mEMCB具有较高的三重态能级(2.42eV),可敏化绿色、红色磷光掺杂材料.同时,mEMCB还具有较好的热稳定性(T_g:79.72℃,T_d:361.49℃),其T_g明显高于目前广泛使用的磷光主体材料CBP.研究结果表明,mEMCB是一个潜在的可以用于绿色和红色磷光有机电致发光器件的主体材料.     

An electron-transporting host material compatible with diverse triplet emitters used for highly efficient red- and green-electrophosphorescent devices

A bifluorene analogue, T2N, containing a pyridyl moiety serves as both a host and an efficient electron-transporting material that is compatible with various heavy metal-containing red (Ir, Ru, Os, and Pt) and green (Ir) phosphors for highly efficient phosphorescent OLEDs possessing simple device architectures.     

Novel thioxanthone host material with thermally activated delayed fluorescence for reduced efficiency roll-off of phosphorescent OLEDs

A symmetrical host material, 2,7-di(9,9-dimethyl-9H-fluoren-1-yl)-9H-thioxanthen-9-one (DMBFTX), with TADF property was firstly developed. The red phosphorescent OLED based on this TADF host displays a lower EQEs rolloff of 38.8% at a luminance of 10 000 cd/m² as compared to 71.2% of commercial mCP host, which is resulted from the upconversion of DMBFTX from triplet to singlet.     

Energy transfer and triplet exciton confinement in polymeric electrophosphorescent devices

Energy transfer and triplet exciton confinement in polymer/phosphorescent dopant systems have been investigated. Various combinations of host‐guest systems have been studied, consisting of two host polymers, poly(vinylcarbazole) (PVK) and poly[9,9‐bis(octyl)‐fluorene‐2,7‐diyl] (PF), blended with five different phosphorescent iridium complexes with different triplet energy levels. These combinations of hosts and dopants provide an ideal situation for studying the movement of triplet excitons between the host polymers and dopants. The excitons either can be confined at the dopant sites or can flow to the host polymers, subject to the relative position of the triplet energy levels of the material. For PF, because of its low triplet energy level, the exciton can flow back from the dopants to PF when the dopant has a higher triplet energy and subsequently quench the device efficiency. In contrast, efficient electrophosphorescence has been observed in doped PVK films because of the high triplet energy level of PVK. Better energy transfer from PVK to the dopants, as well as triplet exciton confinement on the dopants, leads to higher device performance than found in PF devices. Efficiencies as high as 16, 8.0, and 2.6 cd/A for green, yellow, and red emissions, respectively, can be achieved when PVK is selected as the host polymer. The results in this study show that the energy transfer and triplet exciton confinement have a pronounced influence on the device performance. In addition, this study also provides material design and selection rules for the efficient phosphorescent polymer light‐emitting diodes. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2681–2690, 2003     

基于闭环二苯醚与磷氧基团的主体材料的合成及其在蓝色磷光有机发光二极管中的应用

本文通过多步有机反应制备了化合物9-苯基-9′-（4-二苯基氧化膦）苯基-氧杂蒽[diphenyl（4-（9-phenyl-9H-xanthen-9-yl）phenyl）phosphine oxide,DPPO],低温磷光发射光谱测试表明该化合物具有高的三线态能级（2.88eV）,它可以作为天蓝色磷光发光材料双（4,6-二氟苯基吡啶-N,C2）吡啶甲酰合铱[bis（3,5-difluoro-2-（2-pyridyl）phenyl-（2-carboxypyridyl）iridium（Ⅲ）,FIrpic,ET=2.62eV]的主体材料.将主体材料DPPO用于蓝色磷光有机发光二极管中,该器件在100cd/m2的亮度下,电流效率和流明效率分别达到30.6cd/A和19.2lm/W,最大外量子效率达到13.6%.     

Phosphorescent sensitized fluorescent solid-state near-infrared light-emitting electrochemical cells

We report phosphorescent sensitized fluorescent near-infrared (NIR) light-emitting electrochemical cells (LECs) utilizing a phosphorescent cationic transition metal complex [Ir(ppy)(2)(dasb)](+)(PF(6)(-)) (where ppy is 2-phenylpyridine and dasb is 4,5-diaza-9,9'-spirobifluorene) as the host and two fluorescent ionic NIR emitting dyes 3,3'-diethyl-2,2'-oxathiacarbocyanine iodide (DOTCI) and 3,3'-diethylthiatricarbocyanine iodide (DTTCI) as the guests. Photoluminescence measurements show that the host-guest films containing low guest concentrations effectively quench host emission due to efficient host-guest energy transfer. Electroluminescence (EL) measurements reveal that the EL spectra of the NIR LECs doped with DOTCI and DTTCI center at ca. 730 and 810 nm, respectively. Moreover, the DOTCI and DTTCI doped NIR LECs achieve peak EQE (power efficiency) up to 0.80% (5.65 mW W(-1)) and 1.24% (7.84 mW W(-1)), respectively. The device efficiencies achieved are among the highest reported for NIR LECs and thus confirm that phosphorescent sensitized fluorescence is useful for achieving efficient NIR LECs.     

A phosphorescent material with high and balanced carrier mobility for efficient OLEDs

A phosphorescent material (Fppy)(2)Ir(dipba) possessing high PL efficiency in the solid state and superior hole/electron transporting property has acted successfully as an efficient neat phosphorescent emitter as well as an excellent host for high-performance PHOLEDs.     

高效溶液法制备延迟荧光电致发光器件研究

本文以2-[对-N,N-二苯基氨基-苯基]-S-二氧硫杂蒽酮(TXO-TPA)为发光材料, 4,4',4"-三(9-咔唑基)三苯胺(TCTA) 为主体材料, 通过溶液法与真空蒸镀相结合的工艺,制备了高效延迟荧光型电致发光器件。为了考察不同电子传输材料对器件性能的影响,分别选取TmPyPB、TPBI、BCP、Alq₃作为电子传输层制备器件,并对器件的性能进行系统的研究。结果表明:由于1,3,5-三(1-苯基-1H-苯并咪唑-2-基)苯(TPBI)具有合适的HOMO/LUMO能级、高的电子迁移率以及高的三重态能级,利于电子的传输和激子的阻挡,以其为电子传输层的器件显示出最佳的性能,器件的开启电压低至3.6 V,电流效率达到16.2 cd/A,最大的EQE达到5.97%。     

Multifunctional Materials Serving as Efficient Non-Doped Violet-Blue Emitters and Host Materials for Phosphorescence

Efficient multifunctional materials acting as violet-blue emitters, as well as host materials for phosphorescent OLEDs, are crucial but rare due to demand that they should have high first singlet state (S₁) energy and first triplet state (T₁) energy simultaneously. In this study, two new violet-blue bipolar fluorophores, TPA-PI-SBF and SBF-PI-SBF , were designed and synthesized by introducing the hole transporting moiety triphenylamine (TPA) and spirobifluorene (SBF) unit that has high T₁ into high deep blue emission quantum yield group phenanthroimidazole (PI). As the results, the non-doped OLEDs based on TPA-PI-SBF exhibited excellent EL performance with a maximum external quantum efficiency (EQE_max) of 6.76 % and a violet-blue emission with Commission Internationale de L′Eclairage (CIE) of (0.152, 0.059). The device based on SBF-PI-SBF displayed EQE_max of 6.19 % with CIE of (0.159, 0.049), which nearly matches the CIE coordinates of the violet-blue emitters standard of (0.131, 0.046). These EL performances are comparable to the best reported non-doped deep or violet-blue emissive OLEDs with CIEy<0.06 in recent years. Additionally, the green, yellow and red phosphorescent OLEDs with TPA-PI-SBF and SBF-PI-SBF as host materials achieved a high EQE_max of about 20 % and low efficiency roll-off at the ultra-high luminance of 10 000 cd m⁻². These results provided a new construction strategy for designing high-performance violet-blue emitters, as well as efficient host materials for phosphorescent OLEDs.     

A dibenzofuran-based host material for blue electrophosphorescence

Dibenzofuran (DBF) is converted to a vacuum-sublimable, electron-transporting host material via 2,8-substitution with diphenylphosphine oxide moieties. Close pi-pi stacking and the inductive influence of P=O moieties impart favorable electron-transport properties without lowering the triplet energy. A maximum external quantum efficiency of 10.1% and luminance power efficiency of 25.9 lm/W are realized using this material as the host for the blue-green electrophosphorescent molecule, iridium(III) bis(4,6-(di-fluorophenyl)pyridinato-N,C(2')picolinate (FIrpic).