稀土配合物Tb(p-MBA)3phen的有机电致发光

合成了一种新型的稀土铽配合物材料Tb(p-MBA)3phen,把它作为发光材料应用于有机电致发光中.把铽配合物掺杂在导电聚合物PVK中采用旋涂法制得发光层,并利用AlQ作为电子传输层制作了单层、双层有机电致发光器件:器件1(ITO/PVK):Tb(p-MBA)3phen/Al;器件2(ITO/PVK):Tb(p-MBA)3phen/AlQ/LiF/Al,得到了纯正的、明亮的Tb3 离子的绿光发射,4个特征峰分别对应着能级5D4到7Fj(j=6,5,4,3)的跃迁,而PVK的发光完全被抑制.研究了两种器件的电致发光性能,并通过选择AlQ的厚度得到了发光性能较好的器件,其最大亮度在20 V时达到152 cd·m-2.     

铽配合物Tb(o-BBA)3(phen)有机电致发光研究

合成了一种新的稀土配合物邻苯甲酰苯甲酸-1，10-菲罗啉-铽（Tb（o-DDA）3（phen））并用于有机电致发光。研究了Tb（o-DDA）3（phen）与PVK混合薄膜的光敛发光特性，找出了PVK：Tb的最佳比例为3：1。制备了结构为ITO／PVK：Tb／Al的单层电致发光器件，得到了铽离子的特征光谱，其电流-电压特性（I-V）在一定电压范围内符合空间电荷限制电流机制。研究结果表明稀土铽配合物Tb（o-BBA）3（phert）掺杂PVK体系的光致发光是源于PVK到Tb配合物的能量传递及稀土Tb配合物的直接激发两种作用机制，而电致发光以载流子俘获为主。     

苯甲酰水杨酸铽与PVK混合体系的发光特性

合成了一类以苯甲酰水杨酸（benzoyl salicylic acid,BSA)为第一配体，邻菲罗啉（1,10-phenanthroline,Phen)为第二配体的稀土铽配合物，将导电高分子材料PVK引入到配合物中，制成了结构为ITO／PVK：Tb(BSA)3phen/PBD/Alq/LiF/Al电致发光器件，并对该配合物的吸收特性及电致发光和光致发光性能进行了研究，实验数据表明在PVK与Tb(BSA)3phen之间存在着Forster能量传递，该配合物具有很好的光致发光和电致发光性能。本文同时比较了几种不同PVK掺杂浓度对于器件性能的影响。     

稀土配合物的光致和电致发光性能的研究

合成了一种新型的稀土配合物Tb(acac)3dad, 讨论了其光致发光的性质 . 以其为发射层制备了结构为ITO/TPD (50 nm)/Tb(acac)3dad (75 nm)/PBD (50 nm)/Al (400 nm) 的电致发光器件, 该器件的启动电压为7 V, 18 V时得到了最大亮度为62 cd·m -2, 发现器件的电致发光光谱与配合物Tb(acac)3dad的光致发光光谱有明显不同.     

铽配合物[Tb(m-MBA)3phen]2·2H2O的有机电致发光

将稀土铽配合物[Tb(m MBA)3phen]2·2H2O作为发光材料应用于有机电致发光。把铽配合物掺杂在PVK中经甩膜制得发光层,并分别用AlQ和PBD作为电子传输层制作了两类有机电致发光器件。器件1:ITO PVK:[Tb(m MBA)3phen]2·2H2O PBD LiF Al;器件2:ITO PVK:[Tb(m MBA)3phen]2·2H2O AlQ LiF Al,研究了两种器件的电致发光性能,并通过选择AlQ的厚度得到了发光性能较好的用AlQ作为电子传输材料的器件,其最大亮度在20V时达到140cd·m-2。     

铽配合物TbY(o-MBA)6(phen)2与PVK掺杂体系的发光性质研究

合成了一种新型的稀土铽配合物材料TbY(o-MBA)6(phen)2,把它作为发光材料应用于有机电致发光中.把铽配合物掺杂在导电聚合物PVK中采用旋涂法制得发光层,并利用AlQ作为电子传输层制作了多种结构的电致发光器件 器件A,ITO/PVK∶TbY (o-MBA)6(phen)2/LiF/Al;器件B,ITO/PVK∶TbY (o-MBA)6(phen)2/AlQ/LiF/Al;器件C,ITO/PVK∶TbY (o-MBA)6(phen)2/BCP/AlQ/LiF/Al.对器件A和B得到了纯正的、明亮的Tb3+离子的绿光发射,4个特征峰分别对应着能级5D4到7Fj(j=6,5,4,3)的跃迁,而PVK的发光完全被抑制.研究了掺杂体系的光致发光性能和电致发光性能,认为在光致发光中,铽的发光主要来源于PVK到稀土配合物的Frster能量传递.而在电致发光中,铽的发光主要来源于稀土配合物直接捕获载流子形成激子复合发光.并通过优化选择得到了发光性能较好的器件B,其最大亮度在14 V时达到213 cd·m-2.     

铽配合物Tb(2-MBA)_3·2H_2O和Tb(2-MBA)_3 phen的荧光性能研究

以2-甲基苯甲酸(2-MBA)为第一配体、1,10-邻菲罗啉(phen)为第二配体,制备了三元铽配合物Tb(2-MBA)3phen和二元铽配合物Tb(2-MBA)3·2H2O,并利用元素分析、红外光谱、紫外光谱、荧光光谱和荧光寿命对二者的结构与性能进行分析表征。研究结果表明:三元铽配合物Tb(2-MBA)3phen的荧光发射强度要强于二元铽配合物Tb(2-MBA)3·2H2O,而二者的荧光寿命恰好相反,三元铽配合物Tb(2-MBA)3phen的荧光寿命短于二元铽配合物Tb(2-MBA)3·2H2O。热重分析表明Tb(2-MBA)3·2H2O的热分解温度要远高于Tb(2-MBA)3phen。     

一类新型稀土配合物的合成与发光特性研究

合成了一类新型稀土配合物Eu(asprin)3phen和Tb(asprin)3phen,并将其掺杂到导电聚合物PVK中,制成结构了为ITO／PVK：RE配合物／LiF/Al的电致发光器件。很明显,在相同掺杂比例下,前者的电致发光中PVK发射所占比例较大,而后者的电致发光中PVK的发射几乎全部被覆盖掉了,进一步研究发现它们的光致发光中也有同样现象存在,这表明具有同等配体的此类铕、铽配合物的特性存在很大差别,并对这一差别作了初步讨论。     

稀土铽配合物TbY(m-MBA)6(phen)2·2H2O的有机电致发光

合成了两种新型稀土配合物[Tb(m-MBA)3phen]2·2H2O和TbY(m-MBA)6(phen)2·2H2O, 将其掺杂到导电聚合物PVK中用于有机电致发光器件的发光层, 这样改善了配合物的成膜特性和导电性质. 用这种搀杂体系分别制作了单层发光器件和以AlQ为电子传输层的双层器件. 研究了这些单、双层器件的电致发光性能, 对比了以[Tb(m-MBA)3phen]2·2H2O为发光层的双层器件和以TbY(m-MBA)6(phen)2·2H2O为发光层的器件, 发现后者效率更高, 为0.88 cd·A-1, 其最大亮度为123 cd·m-2.     

聚合物掺杂的高亮度磷光有机电致发光器件

采用新型贵金属铱的配合物(pbi)2Ir(acac)作为客体磷光发光材料, 分别以4%和5%(w)的浓度掺杂于聚合物主体材料poly(N-vinylcarbazole) (PVK)中, 利用旋涂工艺制备了结构为indium-tin oxide (ITO)/PVK:(pbi)2Ir(acac)/2,9-二甲基-4,7-二苯基-1,10-菲咯啉(BCP)/Mg:Ag的有机电致发光器件, 对磷光材料(pbi)2Ir(acac)的紫外-可见吸收光谱﹑光致发光光谱以及聚合物掺杂的磷光器件的电致发光特性进行了研究. 结果表明, 两种掺杂浓度的器件均具有8 V左右的启亮电压, 器件在启亮后的最大流明效率分别为1.53和1.31 lm·W-1, 最大亮度分别为11210和9174 cd·m-2; 同时, 器件的电致发光光谱与色坐标均不随偏置电压和客体掺杂浓度的变化而改变, 具有稳定的色纯度. 分析了主体材料PVK到磷光客体(pbi)2Ir(acac)的能量转移机制, 并探讨了随着器件电流密度和客体掺杂浓度的逐渐增加, 器件流明效率的变化趋势.     

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.     

新型含铽共聚物的合成及其电致发光研究

将稀土金属Tb配合物单体与N-乙烯基咔唑（NVK）以及甲基丙烯酸甲酯（MMA）共聚, 合成了一种含Tb配合物的新型聚合物PKMTb, 并以红外光谱、紫外光谱表征了其光谱特性, 研究了其荧光特性和能量转移机制. 利用这种聚合物成功地制成了单层电致发光器件ITO/PKMTb/Al, 其具有半导体二极管的电流-电压特性, 在正相偏压下发绿光, 并探讨了其电致发光机理.     

Electroluminescence performances of 1,1-bis(4-(N,N-dimethylamino)phenyl)-2,3,4,5-tetraphenylsilole based polymers in three cathode architectures

A new silole monomer with two 4-(N,N-dimethylamino)phenyl substitutions on silicon atom as designed and synthesized.Three copolymers PF-N-HPS1,PF-N-HPS10 and PF-N-HPS20 were then obtained by copolymerizations of 2,7-fluorene derivatives with the silole monomer at feed ratios of 1%,10%,and 20%.Their UV-vis absorption,electrochemical,photoluminescent,and electroluminescent (EL) properties were investigated.PF-N-HPS possessed HOMO levels of 5.25-5.58 eV,and showed green emissions.Using PF-N-HPS as the emissive layer,three different polymer light-emitting diodes were fabricated as device A with ITO/PEDOT/PF-N-HPS/Al,device B with ITO/PEDOT/PF-N-HPS/Ba/Al,and device C with ITO/PEDOT/PF-N-HPS/TPBI/Ba/Al.For the device A,PF-N-HPS only showed very low EL efficiency of 0.06-0.33 cd/A,indicating that the Al cathode could not inject electron efficiently to the emissive polymers containing the 4-(N,N-dimethylamino)phenyl groups.For the device B,low work function Ba supplied better electron injections,and the EL efficiency could be improved to 0.85-1.44 cd/A.TPBI with a deep HOMO level of 6.2 eV could enhance electron transport and hole blocking.Thus modified recombinations and largely elevated EL efficiency of 4.56-7.96 cd/A were achieved for the device C.The separation of the emissive layer and metal cathode with the TPBI layer may also suppress exciton quenching at the cathode interface.     

Molecular assembled self-doped polyaniline interlayer for application in polymer light-emitting diode

Self-doped polyaniline (SPANI) ultrathin films were prepared by using a self-assembly process consisting of a self-doping monomer (o-aminobenzenesulfonic acid, SAN) and aniline (AN). SAN-AN copolymerization and film formation were simultaneously performed in aqueous solution. An immersing self-assembly method was developed to build up a SPANI nanofilm on an ITO glass, providing a hole injection layer in a double-layer electroluminescence (EL) device ITO/SPANI nanofilm//MEH-PV//Ca/Al. This device produces an orange EL as compared with a single-layer EL device of ITO//MEH-PV//Ca/Al. A double-layer device demonstrates that a SPANI film is capable of transporting holes in a polymer light-emitting diode (PLED).     

Optimization of high-performance blue organic light-emitting diodes containing tetraphenylsilane molecular glass materials

Molecular glass material (4-(5-(4-(diphenylamino)phenyl)-2-oxadiazolyl)phenyl)triphenylsilane (Ph(3)Si(PhTPAOXD)) was used as the blue light-emitting material in the fabrication of high-performance organic light-emitting diodes (OLEDs). In the optimization of performance, five types of OLEDs were constructed from Ph(3)Si(PhTPAOXD): device I, ITO/NPB/Ph(3)Si(PhTPAOXD)/Alq(3)/Mg:Ag, where NPB and Alq(3) are 1,4-bis(1-naphylphenylamino)biphenyl and tris(8-hydroxyquinoline)aluminum, respectively; device II, ITO/NPB/Ph(3)Si(PhTPAOXD)/TPBI/Mg:Ag, where TPBI is 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene; device III, ITO/Ph(2)Si(Ph(NPA)(2))(2)/Ph(3)Si(PhTPAOXD)/TPBI/Mg:Ag, where Ph(2)Si(Ph(NPA)(2))(2) is bis(3,5-bis(1-naphylphenylamino)phenyl)-diphenylsilane, a newly synthesized tetraphenylsilane-containing triarylamine as hole-transporting material; device IV, ITO/Ph(2)Si(Ph(NPA)(2))(2)/NPB/Ph(3)Si(PhTPAOXD)/TPBI/Mg:Ag; device V, ITO/CuPc/NPB /Ph(3)Si(PhTPAOXD)/Alq(3)/LiF/Al, where CuPc is Cu(II) phthalocyanine. Device performances, including blue color purity, electroluminescence (EL) intensity, current density, and efficiency, vary drastically by changing the device thickness (100-600 A of the light-emitting layer) and materials for hole-transporting layer (NPB and/or Ph(2)Si(Ph(NPA)(2))(2)) or electron-transporting material (Alq(3) or TPBI). One of the superior OLEDs is device IV, showing maximum EL near 19 000 cd/m(2) with relatively low current density of 674 mA/cm(2) (or near 3000 cd/m(2) at 100 mA/cm(2)) and high external quantum efficiency of 2.4% (1.1 lm/W or 3.1 cd/A). The device possesses good blue color purity with EL emission maximum (lambda(max)(EL)) at 460 nm, corresponding to (0.16, 0.18) of blue color chromaticity on CIE coordinates. In addition, the device is reasonably stable and sustains heating over 100 degrees C with no loss of luminance on the basis of the annealing data for device V. Formation of the exciplex at the interface of NPB and Ph(3)Si(PhTPAOXD) layers is verified by EL and photoluminescence (PL) spectra studies on the devices with a combination of different charge transporting materials. The EL due to the exciplex (lambda(max)(EL) at 490-510 nm) can be properly avoided by using a 200 A layer of Ph(3)Si(PhTPAOXD) in device I, which limits the charge-recombination zone away from the interface area.     

Sm(DBM)3phen的光致发光和电致发光性质

制备了一系列基于配合物Sm(DBM)3phen的电致发光器件. 研究了其光致发光(PL)和电致发光(EL)性质, 实验结果表明, Sm(DBM)3phen具有良好的电子注入和传输性能以及电致发光性能. 器件ITO/TPD(50 nm)/Sm(DBM)3phen(50 nm)/Alq3(30 nm)/LiF(1.0 nm)/Al的最大亮度和最大效率分别为150 cd/m2和0.72 cd/A, 器件表现为纯Sm3+离子的发光.     

An organic electroluminescent device with a molecularly doped polymer hole transport layer

Electroluminescent(EL) devices have been fabricated using four different polymers with different glass transition temperatures (T_g) dispersed with N,N′-bis-(3-methylphenyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (TPD) as a hole transport layer and tris(8-hydroxyquinoline) aluminum (Alq₃) as an emitting layer. It was found that the higher the T_g of the polymer, the longer the lifetime of the device. From observations of TPD-doped polymer films with optical microscope and atomic force microscope, dispersing TPD in the polymers was found to suppress the crystallization that causes the roughness of the film surface. It was also observed that the higher the T_g of the host polymers, the more difficult TPD crystallization was. The property of the EL device with polyethersulfone (PES) dispersed with TPD was also investigated. The lifetime of EL device with the TPD doped PES film was improved more than five times at a current density below 10 mA/cm² compared with the device with a conventional TPD hole transport layer. © 1997 John Wiley & Sons, Ltd.     

Organic electroluminescent device based on electropolymerized polybithiophene as the hole-transport layer

An ultrathin film of polybithiophene (PBTh), used in organic electroluminescent (EL) devices, was generated by an electrochemical method with a conducting indium tin oxide (ITO) glass as the working electrode. The light-emitting layer could be deposited directly onto the PBTh by using spin coating for fabrication of the organic EL devices. It was found that the film of PBTh as the hole-transport layer for the EL device could effectively raise the EL intensity and efficiency. The EL intensity of the ITO/PBTh/emitting layer/Al device is about 100 times as strong as that of the ITO/emitting layer/Al device at the same current density of 50 mA/cm².     

Synthesis of Poly[2‐decyloxy‐5‐(4′‐tert‐butylphenyl)‐1,4‐phenylenevinylene] as a Light Emitting Material

In this study, a new electroluminescent poly(2‐decyloxy‐5‐(4′‐tert‐butylphenyl)‐1,4‐phenylene‐vinylene) (designated as DBP‐PPV) with no tolane‐bis–benzyl (TBB) structure defect was prepared by dehydrohalogenation of 1,4‐bisbromomethyl‐2‐decyloxy‐5‐(4′‐tert‐butyl‐phenyl) benzene (as monomer). The monomer bearing decyloxy and 4′‐tert‐butylphenyl substituents was synthesized via alkylation, bromination and Suzuki coupling reactions. The two asymmetric substituents of the monomer can suppress the formation of TBB defect during polymerization process and make the resultant polymer be soluble in common organic solvents. The structure and properties of DBP‐PPV were examined by ¹H‐NMR, FT‐IR, UV/Vis, TGA and photoluminescence (PL) analyses. Moreover, with the DBP‐PPV acting as a light‐emitting polymer, a device with sequential lamination of ITO/PEDOT/DBP‐PPV/Ca/Ag was fabricated. The electroluminescence (EL) spectrum of the device showed a maximum emission at around 546 nm, corresponding to a yellowish‐green light. The device showed a turn‐on voltage of about 8.4 V and a maximum luminescence efficiency of 0.11 cd/A at an applied voltage of 12 V.     

8-羟基喹啉镧两亲性配合物LB膜的双层电致发光器件

以具有不同层数的两亲配合物二[2-(N-十六烷基氨基甲酰基)-8-羟基喹啉]合镧[La(HQ)₂Cl]的LB膜为发光层,PBD为电子传输层,制备了双层结构的电致发光(EL)器件:ITO/LB膜/PBD/Al.器件产生黄绿色注入式发光.LB膜的层数和沉积压对器件的性能具有重要影响.在16V激发电压下,5,11和21层LB膜双层EL器件的电流密度分别为48,29和16.4mA/cm²,启亮电压阀值为7.5,8.5和9.5V.器件的亮度随电流密度和驱动电压的增加而增加.在相同偏压下,21层LB膜EL器件的亮度大于5和11层LB膜的器件.在25mN/m沉积的LB膜制备的EL器件具有较高的亮度(1219cd/m₂)和击穿电压.