加入激子阻挡层增强白色有机发光器件效率

通过在发光层（EBL）与电子注入层之间增加激子阻挡层（EBL）制备了新型白色有机发光器件（WOLED）。有EBL的新型器件效率和亮度均比传统结构器件高50％,在电流密度为4mA／cm^2时效率达到3．42cd／A,最大亮度为11000cd／m^2（16V）,色坐标为x=0．34、y=0．36;而具有相同EBL厚度的传统结构器件,在电流密度为4mA／cm^2时效率为2．15cd／A,最大亮度为6259cd／m^2（16V）。效率的提高是由于EBL的限制作用而提高了激子浓度。测量了器件的效率与电流密度关系,随电流密度增加电流效率的衰减缓慢,说明短寿命红色搀杂剂的激子-激子湮灭很弱。     

利用BCP空穴阻挡层改善白光OLED色度的研究

分别将具有空穴传输特性的蓝光材料pNPB和具有电子传输特性的蓝绿光材料Zn（BTZ）2作为2层发光层，将荧光染料rubrene掺入β-NPB中，在发光层间引入5nm具有空穴阻挡作用的BCP层，制备了一种ITO／PVK：β-NPB：rubrene／BCP／Zn（BTZ）。／Mg：Ag/Ag结构白色有机电致发光器件（OLED）。该器件在5V电压下起亮；18V电压下亮度和色坐标分别为1600cd／m^2和（0．31，0．33），最大外量子效率为0．21％。其色度比不含或含较厚BCP层（〉5nm）的器件均有了很大的改善，并从能带结构和空穴阻挡层厚度2方面探讨了色度改善的原因。     

以Liq:Rubrene为发光层的白色有机电致发光器件的研制

以蓝色发光材料Liq为主体,以一定的比例掺入黄光染料Rubrene,研制了新型白色有机电致发光器件.调节Rubrene的掺杂比为1.1%时得到近白光器件,色坐标为(0.308,0.347),器件的启亮电压为8V,当外加电压达到25V时,器件发光亮度达3120cd/m2.     

以Liq∶Rubrene为发光层的白色有机电致发光器件的研制

以蓝色发光材料Liq为主体,以一定的比例掺入黄光染料Rubrene,研制了新型白色有机电致发光器件.调节Rubrene的掺杂比为1.1%时得到近白光器件,色坐标为(0.308,0.347),器件的启亮电压为8V,当外加电压达到25V时,器件发光亮度达3120cd/m2.     

单层结构白色聚合物电致发光器件制备及其性能

选择梯形对次苯基聚合物(I．PPP)为母体和蓝色发光材料,掺杂MEH-PPV、OXD-7、PMMA分别作为橙红色发光材料、电子传输材料和绝缘介质材料,用旋涂法制成结构为ITO／白色发光层／A1的单层白色有机发光器件。对器件进行热处理(最佳热处理条件为180℃,1h)后,发现器件的发光性能得到明显改善。驱动电压25V时器件的发光亮度由42cd／m^2提高到355cd／m^2,色坐标为(x=0．332,y=0．347),非常接近于白色等能点。     

有机多层白光发光二极管

以四苯基二胺衍生物（ＴＰＤ）为空穴传输材料,以蓝光染料酚基吡啶铍（ＢｅＰＰ２）、黄光染料红荧烯（Ｒｕｂｒｅｎｅ）、绿光染料８－羟基喹啉铝（Ａｌｑ３）分别为蓝、绿、红三基色染料,采用多层结构制备了有机多层白光发光二极管．该白光器件的色坐标为（０．３３,０．３６）（在７Ｖ下）,接近等能点白光（０．３３,０．３３）;该器件在１７Ｖ下的亮度可以达到３０００ｃｄ／ｍ２,流明效率为０．３ｌｍ／Ｗ,是目前报道的比较好的结果     

基于DSA-ph的高效率超薄层蓝色有机电致发光器件

讨论了基于蓝色荧光染料DSA-ph作为发光层的蓝色有机电致发光器件,器件结构为：ITO/2T-NATA/NPBX/DSA-ph（xnm）/TAZ/Bphen/LiF/Al。通过改变DSA-ph的超薄层厚度,相应器件的性能指标也有所不同。研究表明,在超薄层厚度为0.5nm,驱动电压为4V时,器件的最大发光效率为6.57cd/A;在超薄层厚度为0.3nm时,驱动电压为10V时,器件的最大亮度为5 122cd/m^2。器件的色坐标在（0.17,0.36）附近,属于蓝光发射。     

大电流驱动下色度稳定的白色有机电致发光器件

制备了蓝光染料BCzVB和红光染料Btp2Ir(acac)共掺杂的白色有机电致发光器件.保持蓝光染料掺杂浓度为6%而将红光染料掺杂浓度从6%,3%,1%减小到0.2%,器件色坐标从(0.60,0.35)调整至(0.55,0.34),(0.45,0.30)和(0.34,0.27),实现了白光发射.并且,器件在驱动电流4～200 mA/cm2变化范围内,发光色坐标稳定,几乎不随驱动电流密度的增大而漂移.对器件发光光谱和亮度-电流密度曲线等分析表明:器件色度的稳定性是由CBP基质向Btp2Ir(acac)掺杂剂完全的能量传递、蓝光染料BCzVB向红光染料Btp2Ir(acac)不完全的能量传递等内在物理过程决定的.     

高效率非掺杂型白色有机电致发光器件

制备了基于rubrene超薄层和NPBX做激子阻挡层的高效率的非掺杂型白色有机电致发光器件.器件结构为:ITO/2T-NATA(20 nm)/NPBX(25-d nm)/rubrene(0.2 nm)/NPBX(d nm)/DPVBi(30 nm)/Alq(30 nm)/LiF(0.5 nm)/Al.器件的电致发光光谱依靠激子阻挡层NPBX厚度d的变化而变化,当NPBX厚度d为5 nm时,器件色坐标从7 V变化到16 V时均在白光的中心区域,有最大电流效率7.91 cd/A(V=7 V)和最大亮度13 540 cd/m2 (V=16 V).     

高效顶部发光的白光有机电致发光器件

通过改进阳极和阴极，研制成功了高效顶部发光有机电致发光显示器件，为减少不必要的微腔效应，并获得广谱白光，涂镀CFx于银阳极上，以调整反射率，并在Ca／Ag阴极上涂折射率匹配材料（SnO2），获得最大透过率80％。基于蓝光和黄光发射体的双层结构的顶部发光白光有机电致发光器件在20mA／cm^2的电流密度下，在7．3V驱动电压下，最高电致发光效率达到22．2cd／A（9．61m／W）。CIE色坐标为（x=0．31，y=0．47）。     

High-efficiency blue and white organic light-emitting devices by combining fluorescent and phosphorescent blue emitters

High-efficiency blue and white organic light-emitting devices (OLEDs) combined fluorescent and phosphorescent blue emitters were reported. The hybrid blue OLED showed better color purity than that of all phosphorescent device without sacrificing efficiency. The maximum power efficiency of the blue device could reach 23.5 lm/W with the CIE coordinates of (0.163, 0.325). High-efficiency white OLED with maximum power efficiency of 50.6 lm/W was obtained by combined such hybrid blue device and ultrathin phosphorescent yellow emitter. At the practical brightness of 1000 cd/m², the power efficiency of the white device was 28.3 lm/W with a low voltage of 3.37 V and CIE coordinates of (0.40, 0.44). The excitons recombination zone was adjusted by the introduction of the fluorescent blue emitter which resulting a relative high color rendering index and power efficiency of the white device.     

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。     

高效率磷光与荧光相结合的白色有机发光器件

制作了一种白色有机电致发光器件(WOLED)。将红光[Ir(piq)2(acac)]及绿光[Ir(ppy)3]磷光掺杂染料分别掺入到母体CBP中,在2种磷光发光层间插入蓝光材料DPVBi,引入电子传输能力强的BPhen作为电子注入层和空穴阻挡层,通过改变蓝光发光层的厚度,得到了高效率的WOLED,最大电流效率可达17.6cd/A,最大功率效率达13.7lm/W,最大亮度达27525cd/m2,当电压从4V变化到12V时,色坐标从(0.54,0.35)变化到(0.30,0.31),基本处于白光区。器件的特点在于DPVBi的存在阻挡了2种磷光材料间的能量转移,色度可以通过简单地调整DPVBi的厚度,避免使用稀有的蓝光磷光材料和与其相匹配的母体材料,同时又可以保持较高的发光效率。     

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...     

基于ADN的非掺杂高效蓝色OLED器件

采用真空蒸镀的方法,制备了以ADN为发光层的高效率非掺杂蓝色有机电致发光器件.器件的结构为ITO/2T-NATA(15 nm)/NPBx(15 nm)/ADN(25+d nm)/BCP(8 nm)/ Alq_3(30 nm)/LiF(0.5 nm)/Al.通过调整ADN层的厚度,研究了器件的发光性能.测试结果表明,器件在6 V电压时电流效率达到最大,为2.77 cd/A;在16 V时亮度达到最大,为7 227 cd/m~2.当ADN的厚度为30 nm、器件的电压从5 V变化到16 V时,色坐标在(0.21,0.32)至(0.19,0.29)之间,均在蓝光区域.

Abstract：

Using ADN as the emitting layer, high efficient undoped blue organic light-emitting diodes(OLEDs) with a typical structure of (ITO)/ 2T-NATA(15 nm)/ NPBx(15 nm)/ ADN(25+d nm)/BCP(8 nm)/Alq_3 (30 nm)/LiF(0.5 nm)/Al were fabricated via thermal vacuum deposition method. This device has a maximum luminous efficiency of 2.77 cd/A at 6 V and maximum luminance of 7 227 cd/m~2 at 16 V. The CIE coordinates of the device are within the blue region when the thickness of ADN is 30 nm and the voltage changes among the range of 6～16 V.     

Organic light emitting devices employing non-doped structure

11H(1)-benzopyropyrano(6,7-8-i,j)quinolizin-11-one (C545T) with different thicknesses of 0.05 nm, 0.10 nm and 0.20 nm. For comparing, a doped WOLED was also fabricated, in which C545T and DCM2 are codoped into DPVBi layer to provide blue, green and red emission for obtaining white emission. The maximum luminance and power efficiency of the doped WOLED are 5 765 cd/m2 at 16 V and 5.23 lm/W at 5 V, respectively, and its Commission Internationale de l’Eclairage (CIE) coordinate changes from (0.393 7, 0.445 3) at 5 V to (0.300 7, 0.373 8) at 12 V. When the thickness of the ultrathin C545T layer in non-doped WLEDs increases, the emission luminance increases, but all non-doped devices are in the yellow white region. The device with 0.10-nm-thick C545T has a maximum efficiency of 15.23 cd/A at 8 V and a maximum power efficiency of 6.51 lm/W at 7 V, and its maximum luminance is 10 620 cd/m2 at 16 V. CIE coordinates of non-doped WLEDs with C545T thickness of 0.05 nm, 0.10 nm and 0.20 nm are (0.447 3, 0.455 6), (0.464 0, 0.473 1) and (0.458 4, 0.470 0) at 8 V, respectively. This work has been supported by the Major Project of Science and Technology Office of Fujian Province of China (No.2014H0042), the Natural Science Foundation of Fujian Province of China (No.2015J01664), the Project of Science and Technology Research of Quanzhou in Fujian Province of China (Nos.2013Z125 and 2014Z137), and the 2016 Annual National or Ministries of the Quanzhou Normal University Prepare Research Foundation Project (No.2016YYKJ21).E-mail:lishuangw@126.com      

双发光层白色FOLED的制备及其性能研究

采用以含ITO导电层的柔性透明PET基片作为衬底,荧光材料TBPe、Rubrene分别掺杂在主体材料CBP和Balq中作为蓝色发光层和橙红色发光层,制备了双发光层白色柔性有机电致发光器件(FOLED)。通过适当调节发光层的掺杂比例和厚度,得到了发光性能理想的白光器件。测量表明,制备的器件色稳定性很好,色度随外加驱动电压在很大范围内变化很小,且其色坐标均非常接近于白色等能点。当电流密度为50mA/cm2时,器件最高外量子效率达到0.9%。通过抗弯折性能的测试证明,可以基本实现柔性显示的目的。     

双发光层白光有机电致发光器件的研究

将DCJTB掺杂入Alq3中,作为黄光发光层,制作了一种基于新型蓝光材料PAA的白光有机电致发光器件(OLED).器件的结构为ITO/NPB/PAA/Alq3:DCJTB/Alq3/Mg:Ag,通过PAA层的蓝光与Alq3:DCJTB层的黄光混合实现了很好的白光发射.结果表明,器件在4.6V时启亮,在5.2V时达到最大...     

Efficient white organic light-emitting device based on a thin layer of hole-transporting host with rubrene dopant

A white organic light-emitting device (WOLED) in which a yellow fluorescent dye, rubrene (5,6,11,12-tetraphenylnaphthacene), is doped into a thin layer of traditional hole-transporting material NPB {4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl} is fabricated. The device has a simple structure of indium tin oxide (ITO)/CuPc/NPB/NPB: 0.7 wt.% rubrene/TPBI/lithium fluoride (LiF)/Al, where CuPc (copper phthalocyanine) and TPBI {2,2′,2″-(1,3,5-benzenetriyl)tris[1-phenyl-1H-benzimidazole]} are used as the hole-injecting layer and electron-transporting and hole-blocking layer, respectively. The device exhibits peak efficiency of 3.7 cd/A (2.1 lm/W) at 5.5 V and maximum brightness of 8200 cd/m² at 20 V. The Commission Internationale de l’Eclairage (CIE) coordinates of (0.291, 0.303) are determined at 6 V. When the bias increased from 6 V to 14 V, the colour coordinates shifted only by 2%, which is presumably related closely to the thickness of the doped NPB layer. Besides, the electroluminescent (EL) efficiency can also be improved by decreasing the thickness of the doped NPB layer. The mechanisms of generating stable white colour and improving EL performances are also discussed.