高饱和度蓝色磷光有机发光器件

使用典型天蓝色磷光材料FIrpic作为磷光金属微腔有机发光器件（OLED）的发光层,以高反射的Al膜作为阴极顶电极和半透明的Al膜作为阳极底电极,采用空穴和电子注入层MoO3和LiF,制备了结构glass／Al（15nm）／MoO3（znm）／NPD（40nm）／mCP：Flrpic（30Ftm,7％）／BCP（20n...     

加入电子阻挡层的黄色磷光有机电致发光器件

使用绿色磷光材料GIr1和红色磷光材料R-4B作 为掺杂剂,制备了一种黄色磷光有机电致发光 器件(OLED),其结构为ITO/MoO₃(60nm)/NPB(40nm)/TCTA(x nm,x＝0、5、10和15)/CPB:GIr1:R -4B(30nm,14%,2%) /BCP(10nm) /Alq₃(40nm)/LiF(1nm)/Al( 100nm)。其中x＝0,5,10,5nm。通过在发光层与空穴传输层之间增 加电子阻挡层TCTA,使器件的效率得到提高。当TCTA厚为10nm时, 起亮电压为4V左右,器 件的最大发光效率为20.2cd/A,最高亮度可以达到21840cd/m²,器件的色坐标 为(0.42,0.53)。器件的EL主峰位于524nm 和604nm。并且当电流 密度为2.49mA/cm²时,10nm厚的TCTA 电子阻挡层的器件发光效率是不加入TCTA的器件发光效率的2倍。发光效率的提高是由于电 子阻挡层的加入限制了空穴传输层NPB的发光,从而使更多的激子在发光层中复合。     

高亮度微腔有机电致发光器件

为了实现有机电致发光器件(OLED)发射光谱的窄化和高亮度,真空热蒸镀具有不同微腔结构的OLED(MOLED):玻璃衬底/分布式布拉格反射器(DBR)(1～4对的SiO2/Ta2O5层)/ITO/空穴传输层(HTL,α-NPD)/发光层(EML,Alq3:Rubrene或Alq3:Coumarin6)/电子传输层(ERL,Alq3)LiF/Mg/Ag,其中沉积DBR结构采用电子束沉积法。实验表明:该MOLED的发射光谱半波长宽度(FWHM)随DBR层数的增加而减小至最小值10nm;并且在2层DBR时,掺杂Rubrene器件得到更大的电流效率,约20cd/A,最大亮度为2.6×105cd/m2。研究发现,蓝光MOLED能够对自发光产生吸收现象,降低了出光效率。     

白光有机电致发光器件发光稳定性研究

基于红绿/蓝双发光层,制作了结构为ITO/MoO ₃(10nm)/NPB(40nm)/TCTA(10nm)/CBP:R-4B(2%):GIR1(14%,X nm)/mCP:Firpic(8%,Y nm/BCP(10nm)/Alq₃(40nm)/LiF(1nm)/Al( 100nm)的白色全磷光有机电致发光器件(OLED),通过 调节红绿发光层的厚度X与蓝光发光层的厚度Y,研究了不同发光层厚度器件发 光性能的影响。研究发现:当X 为23nm、Y为7nm时,器件的光效和色坐标都具有 很高的稳定性,在电压分别为5、 10和15V时,色坐标分别为(0.33,0.37)、(0.33,0. 37)和(0.34,0.38);在电压为 5V时,电流密度为0.674mA,亮度为158.7cd ,最大电流效率为26.87cd/A;利用电子阻 挡材料TCTA和空穴阻挡材料BCP能够显著提高载流子的复合效率。分析认为:发光层顺序 为红绿/蓝时,更有利于蓝光的出射,从而使白光的色坐标更稳定。     

基于DPV的高效率蓝光有机电致发光器件

制备了基于荧光染料2-diphenylamino-7-(2,2 diphenylvinyl)-9,9'-spriobifluoreme(DPV)的高效率蓝光有机电致发光器件(OLED).器件的结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/DPV(d nm)/BCP(10 nm)/Alq3(30 n...     

高效绿色磷光有机电致发光器件

使用绿色磷光材料GIr1作为掺杂剂,制备了基于CBP材料的一系列绿色有机电致发光器件(OLED)。其器件的结构为ITO/MoO3(50nm)/NPB(40nm)/TCTA(10nm)/CPB:GIr1(30nm,x%)/BCP(10nm)/Alq3(20nm)/LiF(1nm)/Al(100nm),其中x%为发光层客体掺杂质量分数。对7种不同的掺杂剂质量分数进行了比较,研究了它们的电致发光(EL)特性。结果显示,对发光面积为2.72cm2的器件,GIr1的最佳掺杂比为14%,器件的起亮电压为3.5V,器件的最大电流效率26.2cd/A,其相应的EL主峰位于524nm,色坐标为(0.34,0.61),得到了发光性能稳定的绿色OLED。     

微腔结构对红光磷光OLED的性能的影响研究

使用新型红光磷光材料R-4B作为微腔有机电致发光显示器(OLED)的发光层,高反射Al阴极和半透半反Al阳极为微腔的两端反射镜。制备的器件结构为Al(10nm)/MoOx(Ynm)/NPB(40nm)/TCTA(10nm)/CBP:R-4B(4%)(30nm)/BCP(10nm)/AlQ(40nm)/LiF(1nm)/Al(100nm)。讨论了腔长的变化对器件性能的影响。结果表明,微腔结构可以使光谱窄化,随着MoOx厚度Y的增加,其峰值波长由600nm增至668nm。当MoOx厚度为40nm时,其发光强度最大,峰值波长为608nm,半高宽(FWHM)为50nm,器件的最大亮度为35 300cd/cm2,最大效率可达23.5cd/A,得到了性能较好的红色磷光OLED。     

高效率绿色磷光有机电致发光器件

采用真空蒸镀的方法,在真空度为5.0×10－4 Pa条件下,分别以传统的材料CBP、TCTA为主体材料,绿色磷光染 色材料(Ir(ppy)₃)为客体材料,制备了相应的有机电致发光 器件,研究发现采用CBP做主体材料的器件比采用TCTA做主体材料的器件能量传递更充 分。之后制备了结构为ITO/NPB(y_1nm)/ CBP:Ir(ppy)₃(x%,y nm)/TPBi(y_2nm)/LiF(0.5nm)/Al 的有机电致发光器件,进一步探究了器件磷光染色材料的掺杂比、器件总厚度对器件性能的 影响。实验结果表明,以CBP为掺杂主体材料,y=20nm,y₂=40nm,x%=8%,当y₁=65nm, 器件亮度达到最高,为67760cd/m²。当y₁=40nm时 ,器件功率效率最高,为41.2lm/W。与此同时,OLED器件的色坐标 均为(0.30,0.61)。     

一种基于液晶性质的Pt配合物磷光材料电致发光器件

采用聚合物掺杂的方式,利用旋涂工艺制备了ITO/PVK:TOPPt/BCP(20 nm)/Mg:Ag(200 nm)结构的有机电致发光器件(OLED)。对掺杂浓度为2%(器件A)和4%(器件B)的磷光聚合物掺杂体系的光致发光(PL)和电致发光(EL)性质进行了分析研究,并对主体材料PVK到磷光客体材料TOPPPt的能量传递机制进行了讨论。实验表明,器件的EL谱谱峰位于625 nm,器件A在25 V时最大亮度为3037 cd/m2,最大电流效率为3.15cd/A。器件的EL谱不会随着偏置电压和掺杂浓度而改变,器件具有较好的稳定性。     

一种新型插层结构的有机电致发光器件

报道了一种新型插层结构的有机电致发光器件(OLED),LiF(1 nm)/Al(5 nm)插层作为半反射镜,与LiF(1 nm)/Al(100 nm)作为全反射镜面的阴极构成平面Fabry-Perot(F-P)型微腔,所用发光层材料为Zn(salen),器件的结构为:ITO/CuPc/NPD/Zn(salen)/Liq/LiF/Al/CuPc/NPD/ Zn(salen)/Liq/LiF/Al,其最大发光亮度和电流效率分别达674 cd/m2 和 2.61 cd/A,半峰宽(FWHM)为48 nm.与传统结构器件相比,色纯度、发光亮度和发光效率等性能指标均得到了优化.     

微腔结构顶发射有机白光器件

结合微腔效应,通过调节不同发光层的厚度制作了顶发射有机白光器件.器件结构为Si/Ag/Ag2O/m-MTDATA/NPB/DPVBi/DCJTB:Alq3/Alq3/LiF/Al/Ag,其中DPVBi,DCJTB与Alq3的掺杂层分别作为蓝光和红光发光层,在选定490 nm的谐振波长时,通过调节DPVBi和掺杂层的厚度来实现对器件发光色度的调节.当DPVBi厚度为1 nm,电压为9 V时,器件的色坐标为(0.33,0.34),非常接近白光等能点.此项工作为利用微腔效应制作高效率高亮度顶发射白光器件奠定了基础.     

高浓度掺杂Ir(ppy)3和Rubrene的高效率有机发光器件

通过采用CBP主体材料中高浓度掺杂Ir(ppy)a和Rubrene,利用Ir(ppy)3敏化黄光发射的方法,制备了高性能的有机电致发光器件(OLED).器件采用的结构为:ITO/2T-NATA(20 nm)/NPBX(40 nm)/x%CBP:y%(ppy)3:z%rubrene(20 nm)/NPBX(10 nm)/DPVBi(60 nm)/Alq(60 nm)/LiF(1 nm)/Al,在该器件中限定.各功能层的厚度保持不变,当CBP、Ir(ppy)3、Rubrene各组分的比例x、y、z分别为:65%、20%、15%时,器件的性能较好,在电压为12 V时,其电流效率最大为21.1 ed/A.在电压为24 V时,其亮度为最大,达到22 670 ca/m2.该器件的色度随电压的增加逐步趋近于白光等能点(0.33,0.33).     

异质结堆叠发光层红色磷光有机发光二极管

本文采用主客体交错结构的发光层,即发光层是 由多组主体材料CBP和客体材料Ir(piq)₂(acac)异质结堆叠构成的。为了改善器件的性能 ,分别优化 了单主体层和单客体层的厚度。研 究表明,单主体层厚度为3~4 nm,单客体层厚度为0.3 nm时,器件能够获得的最大电流效率为3.92 cd/A,色纯度 和发光稳 定性俱佳,1mA工作电流下的CIE色坐标为(0.669,0.308),当工作电流从0.1 mA变化 到1mA,色度坐标的变化值(Δ(x,y)) 仅为(0.004,0.002)。所采用的 主客体交错发光层的制备方法,工艺简单,且因为能分别调整主客体层的厚度而改善因客体 分子聚集或因长程偶极子间相互作用对发光效率的影响,为非掺杂磷光有机发光二极管的制 备提供了思路。     

Phenylimidazole-based homoleptic iridium(III) compounds for blue phosphorescent organic light-emitting diodes with high efficiency and long lifetime

In order to obtain triplet emitters with high stability and efficiency, three homoleptic iridium(III) compounds — specifically, Ir(tpim)₃ (1), Ir(mtpim)₃ (2), and Ir(itpim)₃ (3), where tpim = 1-([1,1′:3′,1″-terphenyl]-2′-yl)-2-(4-fluorophenyl)-1H-imidazole, mtpim = 2-(4-fluorophenyl)-1-(5′-methyl-[1,1′:3′,1″-terphenyl]-2′-yl)-1H-imidazole, and itpim = 2-(4-fluorophenyl)-1-(5′-isopropyl-[1,1′:3′,1″-terphenyl]-2′-yl)-1H-imidazole — were prepared by one-pot reaction of the corresponding phenylimidazole ligand with an Ir(I) complex as a starting material. Compounds 1–3 emit bright sky-blue phosphorescence with λ_max = 459–463 nm and phosphorescent quantum efficiencies of 0.38–0.50. Multi-layer phosphorescent organic light-emitting diodes using compounds 1–3 as the triplet emitters and mCBP (3,3-di(9H-carbazol-9-yl)biphenyl) as the host have been fabricated. Compound 3 doped in the emissive layer demonstrate external quantum efficiency as high as 20.1% at 1000 cd/m². In addition, the device based on compound 1 as an emitter shows a stable lifetime greater than 300 h at 1000 cd/m², which is one of the best results concerning the device lifetime.     

(t-bt)2Ir(acac)超薄层厚度对有机电致发光器件性能的影响

以新型铱配合物黄光磷光染料bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2']iridium(acetylacetonate)[(tbt)2Ir(acac)]为超薄层,制备了结构为indium tin oxide(ITO)/N,N'-bis(naphthalen-1-yl)-N...     

meta-Linked spirobifluorene/phosphine oxide hybrids as host materials for deep blue phosphorescent organic light-emitting diodes

This study investigated the use of a novel modification in molecular design to get two new electron-transport host materials, SF3PO and BSF3PO. By linking the phosphine oxide moieties at meta-position of spirobifluorene rings, higher triplet energies could be easily achieved for these two new materials. The steric spirobifluorene structures could guarantee their good thermal stabilities. According to these properties, their applications as host materials for deep blue phosphorescent organic light-emitting diodes (PHOLEDs) were explored. As expected, the deep blue emitting devices with Ir-complex FIr6 as phosphorescent dopants and SF3PO and BSF3PO as hosts had been fabricated and showed high efficiency of 28.5 and 22.0 cd/A, respectively, which were significantly higher than that of the para-linked analogue SPPO1.     

Correlation between interlayer thickness and device performance in blue phosphorescent organic light emitting diodes with a quantum well structure

We systematically examined the effects of interlayer (ITL) thickness variation in an emission layer (EML) on electrical and optical characteristics of blue phosphorescent organic light-emitting diodes. The EML consisted of a quantum well structure using a hole transport material 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) as an ITL. This ITL facilitated the confinement of charge carriers in the recombination zone (RZ), adjusted the charge carrier balance in the EML, and prevented the triplet exciton loss to adjacent transport layers. The thickness variation in the ITL greatly influenced the size and location of the RZ and the exciton density (ED), which is related to charge balance and exciton diffusion in the EML. A micro-cavity effect around 500 nm and the corresponding redshift/blueshift in the electroluminescent spectrum arose from different ITL thicknesses. Remarkably, the device having a 5-nm-thick TAPC ITL showed better current and power efficiencies than those of any other devices because of the rearrangement of the locations of excitons and ED through control of the hole/electron charge density.