利用磷光敏化和空穴阻挡层提高白光OLED性能

利用磷光敏化和BCP的空穴阻挡作用,制备了结构为:ITO/2T-NATA(15nm)/NPBX(20nm)/rubrene(0.2nm)/NPBX(5nm)/CBP∶6%Ir(ppy)3∶15%ADN(30nm)/BCP(10nm)/Alq3(25nm)/LiF(0.5nm)/Al的有机白光器件。器件在电压为7V的情况下,最大发光效率达到5.80cd/A,在12V的电压下最大亮度达12395cd/m2,色坐标为(0.30,0.30),接近白光等能点(0.33,0.33),比非敏化器件最大发光效率3.10cd/A(7V)和最大亮度10390cd/m2(12V)及非敏化不加空穴阻挡层BCP的器件最大发光效率2.13cd/A(8V)和最大亮度8852cd/m2(12V)的性能提高很多。     

基于NPBX掺杂CzHQZn的黄色有机电致发光器件

利用一种既具有空穴传输特性又具有发光特性的新型荧光染料N-乙基咔唑-2-乙烯基-8-羟基喹啉锌[(E)-2-(2-(9-ethyl-9H-carbazol-3-yl)vinyl)quinolato-zinc,CzHQZn]掺杂在NPBX中作为空穴传输层,CzHQZn同时还作为发光的主体,制备了结构为ITO/2T-NATA(30nm)/NPBX:25%CzHQZn(xnm)/BCP(10nm)/Alq3(60-x)nm/LiF(0.5nm)/Al的有机发光器件(x为掺杂发光层的厚度),掺杂发光层的厚度按照15,20,25,30nm进行变化,相应改变Alq3的厚度,使得这两者的总厚度为60nm保持不变。当掺杂发光层的厚度是20nm,Alq3的厚度是40nm,其他层厚度保持不变时,器件在4V电压下实现了黄光发射,色坐标为(0.514 6,0.470 5),亮度是1.078cd/m2。在14V的电压下,器件最大发光亮度为449 0cd/m2,最大发光效率为0.98cd/A。     

以CzHQZn为主体的有机发光器件的发光效率

采用真空热蒸镀技术,分别制备了结构为ITO/2T-NATA(25nm)/CzHQZn(10～25nm)/TPBi(35nm)/LiF(0.5nm)/Al、ITO/2T-NATA(30nm)/CBP:6%Ir(ppy)3:x%CzHQZn(20nm)/Alq3(50nm)/LiF(0.5nm)/Al和ITO/2T-NATA(30nm)/CBP:6%Ir(ppy)3:10%CzHQZn(xnm)/Alq3((70-x)nm)/LiF(0.5nm)/Al的3组有机电致发光器件(OLED)。器件中,CzHQZn既有空穴传输特性,又是黄光发射的主体。为了提高其发光效率,利用磷光敏化技术,研究了掺杂层中不同掺杂浓度和掺杂层不同厚度时器件的发光效率。结果表明,器件的效率随着掺杂发光层的厚度和掺杂浓度的变化而改变,当发光层的厚度为18nm时,CzHQZn掺杂浓度为10%的器件性能较好;在10V电压下,器件的最大电流效率达到3.26cd/A,色坐标为(0.4238,0.5064),最大亮度达到17560cd/m2。     

基于MCzHQZn的有机电致发光器件

通过结构为ITO/2T-NATA(20nm/NPBx(20nm)/MCzHQZn(30nm)/BCP(10nm)/Alq3(20nm)/LiF(0.5nm)/Al、ITO/2T-NATA(30nm/MCzHQZn(30nm)/BCP(10nm)/Alq3(30nm)/LiF(0.5nm)/Al和ITO/2T-NATA(20nm/MCzHQZn(30nm)/NPBx(16nm)/BCP(10nm)/Alq3(25nm)/LiF(0.5nm)/Al的3组有机电致发光器件(OLED),证明了MCzHQZn既具有空穴传输特性,又具有较好的发光特性。MCzHQZn在器件1中作发光层,器件最大亮度在电压16V时达到3692cd/m2,电压13V时的最大效率为0.90cd/A,发光的峰值波长为564nm;MCzHQZn在器件2中既作发光层又作空穴传输层,器件最大亮度在电压为13V时达到1929cd/m2,电压12V时的最大效率为0.57cd/A,发光的峰值波长也为564nm;MCzHQZn在器件3中作空穴传输层,由NPBx作发光层,器件最大亮度在电压为14V时达到3556cd/m2,电压9V时的最大效率为1.08cd/A,发光的峰值波长为444nm。     

基于FHQZn发光的新结构有机黄光器件

利用一种新型材料(E)-2-(2-(9H-fluoren-2-yl)vinyl)quinolato-Zinc(FHQZn)制备了一种新结构的黄光OLED,器件的结构为:indium-tinoxide(ITO)/4,4′,4″-{N,-(2-naphthyl)-N-phenylamino}-triphenylamine(2T-NATA)(15nm)/FHQZn(xnm)/4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl(DPVBi)(20nm)/2,2′,2″-(1,3,5-phenylene)tris(1-phenyl-1H-benzimidazole-(TPBi):6%factris(2-phenylpyridine)iridium(Ir(ppy)3)(45nm)/LiF(0.5nm)/Al,FHQZn作空穴传输层和黄色发光层,DPVBi作空穴阻挡层,TPBi中掺杂Ir(ppy)3作电子传输层;研究了发光层FHQZn的厚度对该器件的发光性能的影响。当FHQZn厚度x=25时,得到了效率和亮度最大的黄光器件,最大电流效率为1.31cd/A(at13V),最大亮度为5705cd/m2(at14V),此时色坐标为(0.4,0.5516)。     

基于FHQZn发光的色度稳定的有机白光器件

研究了一种新型发光材料(E)-2-(2-(9H-fluoren-2-yl)vinyl)quinolato-Zinc的发光性能,利用它的空穴传输和发光特性制备了有机白光器件,器件的结构为:ITO/2T-NATA(15nm)/FHQZn(38nm)/NPB(25nm)/BCP(10nm)/Alq(30nm)/LiF(0.5nm)/Al,其中,(E)-2-(2-(9H-fluoren-2-yl)vinyl)quinoato-Zinc(FHQZn)作为空穴传输层和黄橙色发射层,N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine(NPBX)作为蓝光发射层。器件最大的电流效率为1.68cd/A(at7V),最大的亮度为4624cd/m2(at12V),此时色坐标为(0.28,0.25)。器件的色坐标由7V(66.83cd/m2)时的(0.27,0.29)到12V(4624cd/m2)时的(0.28,0.25)几乎不变,是一个基于新型材料的色度较稳定的有机白光器件。     

CdS薄层对有机电致发光器件性能的影响

将光电材料硫化镉(CdS)薄层插入到结构为ITO/NPB/Rubrene/NPB/DPVBi/Alq3/LiF/Al的白光有机发光器件(OLED)的Alq3和LiF之间,研究了CdS对OLED性能的影响。结果表明,0.1nm厚的CdS插入Alq3和LiF之间的器件性能最好。器件电压从7 V变化到14 V时,色度均在白光的中心区域;当电压为7V时,器件的最大电流效率为9.09cd/A;当电压为14V时,器件的最大亮度为16 370cd/m2。不加CdS时,当电压为8V时,器件的最大效率为5.16cd/A;当电压为14V时,最大亮度为6 669cd/m2。加CdS的器件比不加CdS的器件最大效率提高了1.76倍,最大亮度提高了2.42倍。     

利用DPVBi的空穴阻挡和发光特性而制作的白光器件

介绍了结构为:ITO/m-MTDATA(40 nm)/NPB(5 nm)/DPVBi(10～12 nm)/Rubrene(0.5 nm)/DPVBi(20～18 nm)/Alq(50 nm)/LiF(0.5 nm)/Al的白光器件.该器件采用了两个DPVBi层中间夹一个Rubrene的薄层,这种结构充分利用了DPVBi的空穴阻挡特性和发光特性,有力地平衡了来自于DPVBi的蓝光、Alq的绿光和Rubrene的黄光,从而使器件发射性能较好的白光.当第一层的DPVBi和第二层的DPVBi的厚度分别是11 nm和19 nm时,其他层的厚度保持不变,该器件在15 V电压下,最大亮度为11 290 cd/m2 ,对应的效率为1.71 cd/A,色坐标为(0.25,0.27),属于白光发射;在6 V时,其最大效率为3.18 cd/A.     

利用多阱结构改善有机电致发光器件效率

将N,N'-bis-(1-naphthy1)-N,N'-dipheny-1,1'bipheny1 4,4'-diamine(NPB)与bathocuproine(BCP)2种材料以交叠沉积方式组成一种周期性结构作为空穴注入层,制备了结构为ITO/[NPB/BCP]n/AlQ/LiF/Al的有机电致发光器件(OLED).通过改变空穴注入层阱状结构的重复周期数n,可改变载流子复合区域,进而获得近白光和绿光发射.由于该结构能获得更好的载流子注入平衡,具有交叠结构空穴注入层的近白光器件在15 V时亮度达到3 433.8 cd/m2,在电流密度为60.9 mA/cm2时最大发光效率为2.26 cd/A.当周期数n大于3时得到绿光发射,与单空穴注入层ITO/NPB/AlQ/LiF/Al器件相比,交叠空穴注入层可将器件的最大亮度由2 512.8 cd/m2提高到866 1.0 cd/m2,最大亮度效率在20 mA/cm2时达到4.94 cd/A.     

无氧溅射方法制备OLED的ITO透明电极

采用氧化铟锡(ITO)合金材料作为靶材,通过射频磁控溅射制备ITO膜.将获得的ITO膜应用于结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/Alq3(50 nm)LiF(0.8 nm)/Al(100 nm)的有机电致发光器件(OLED),得到了最大亮度为11560 cd/m2(电压为25V)、最大效率为2.52 cd/A(电压为14 V)的结果.为了获得双面发光,制作了结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/Alq3(50 nm)LiF(0.8 nm)/Al(20 nm)/ITO(50 nm)的器件,其阳极出光的最大亮度为14460 cd/m2(电压为18V)、最大效率为2.16 cd/A(电压为12V),阴极出光的最大亮度为1 263 cd/m2(电压为19 V)、最大效率为0.26 cd/A(电压为16V).     

不同空穴阻挡材料对白色OLED性能的影响

采用Alq3、TPBi和BCP分别作为电子传输材料和空穴阻挡材料,制备了三种器件,研究了用不同的空穴阻挡材料对器件性能的影响。实验结果表明:只采用30nm Alq3作电子传输层的器件的电流效率最大值为7.84cd/A(9V),而采用10nm Alq3作电子传输层,插入20nm的BCP和TPBi作空穴阻挡层的器件获得的电流效率最大值分别为9.72cd/A和12.21cd/A(9V)。这些结果说明空穴阻挡材料能改善器件的性能,TPBi比以BCP作为空穴阻挡层的器件性能有了很大的改善,制备的白色OLED的最大亮度和电流效率分别为22400cd/m2(17V)和12.21cd/A(9V)。     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

一种新的多发光层白色有机电致发光器件

采用多发光层结构,将一种新型的黄橙色荧光染料2-溴-4-氟苯乙烯-8-羟基喹啉锌(BFHQZn,(E)-2-(2-bronw-4-fluorostyryl)quinolato-Zinc)与蓝色9,10-二-2-蔡蔥(ADN)组合在一起实现白光.研究了插入4,4-N,N-二咔唑联苯(CBP)对器件色度的影响,通过改变发光...     

Efficient fluorescent white organic light-emitting devices based on a ultrathin 5,6,11,12-tetraphenylnaphthacene layer

White organic light-emitting devices (OLEDs) were fabricated using a ultrathin layer 5,6,11,12-tetraphenylnaphthacene as the yellow light-emitting layer and p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-ph) doped in 2-methyl-9,10-di(2-naphthyl)anthracene (MADN) matrix as the blue light-emitting layer. The thickness of rubrene ultrathin layer will seriously affect the device performance, and the device with 1 nm rubrene achieves the best performance, with the maximum luminance of 33,152 cd/m² at 11 V and the maximum current efficiency of 8.69 cd/A at 7 V.     

Organic light-emitting devices with a 2-(4-biphenyl)-5-(4-butylphenyl)-1,3,4-oxadiazole layer between the α-naphtylphenyliphenyl diamine and 8-hydroxyquinoline aluminum

Organic light-emitting devices (OLEDs) with a 2-(4-biphenyl)-5-(4-butylphenyl)-1,3,4-oxadiazole layer between the α-naphtylphenyliphenyl diamine and 8-hydroxyquinoline aluminum were fabricated using a vacuum evaporation method. Compared to the different thickness of the buffer layer, the OLEDs with the 1.0 nm buffer layer showed the maximum power efficiency. The enhancements in power efficiency result from an improved balance of hole and electron injections. After comparing among different density buffer layer, PBD are good candidates for hole-injecting buffer layer, and 1.0 nm PBD buffer layer shows better operational durability and life.     

(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...     

Properties of non-doped organic light-emitting devices based on an ultrathin iridium complex phosphor layer

Organic light-emitting devices (OLEDs) were constructed with a structure of indium tin oxide (ITO)/N,N'-bis(naphthalen-1-yl)-N'-bis(phenyl)-benzidine (NPB) (50-xnm)/bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2'] iridium (acetylacetonate) [(t-bt)2Ir(acac)] (nm)/NPB (30nm)/Mg:Ag (200nm).A thin blue emission material of NPB was used as a separating layer,and the (t-bt)2Ir(acac) yellow phosphorescent dye was acted as an ultrathin light-emitting layer.TPBI acted as both hole-blocking and electron-transporting layer.By changing the location (x) and the thickness (d) of the phosphor dye,the variation of device performance were investigated.The results showed that all the devices had a turn-on voltage of 2.8V.In the case of d=0.2nm and x=5nm,the OLED had a maximum luminance of 18367cd/m2 and a maximum power efficiency of 5.3lm/W.The high performance is attributed to both direct charge carrier trapping of iridium phosphor dye and the thin NPB separation layer,which effectively confines the recombination zone of charge carriers.