Synthesis and Photoelectric Properties of Bipolar Host Material 9-phenyi-3- ( phenylsulfonyl ) -6- ( triphenylsilyl ) -9 H-carbazole

设计开发了一种新的双极性蓝色磷光主体材料,将其搭配Firpic应用于简单器件结构,通过调整器件中载流子传输层的厚度得到了比较满意的结果:最大电流效率40cd/A,最大亮度19691cd/m2,最大流明效率12lm/W.这一结果说明所开发的主体材料能够很好的平衡载流子的注入与传输能力,具有适宜的三线态能量和良好的热稳定性,是一种优良的蓝色磷光主体材料.     

基于7-(9H-carbazol-9-yl)-N,N-diphenyl-9,9'-spirobi[fluoren]-2-amine主体材料的高效红色电致磷光器件

研究了基于新型骨架7-(9H-carbazol-9-yl)-N,N-diphenyl-9,9'-spirobi[fluoren]-2-amine(CzFA)双极性主体材料的红色电致磷光器件的光电特性。研究结果表明:将红色磷光染料iridium(Ⅲ)bis[2-methyldibenzo-(f,h)quinoxaline](acetylacetonate)(Ir(MDQ)2(acac))掺杂到CzFA主体材料中,以其制备的电致发光器件具有优良的特性,最大电流效率为27.8 cd/A,最大功率效率为21.8 lm/W,最大功率效率几乎是先前报道的主体材料为CBP器件(13.7 lm/W)的1.6倍。这种咔唑-螺二芴-二胺基团所组成的双极性主体材料对于提升磷光器件的性能起到了重要的作用。     

基于7-（9H-carbazol-9-yl）-N,N-diphenyl-9, 9’-spirobi[fluoren]-2-amine主体材料的高效红色电致磷光器件

研究了基于新型骨架7-（9H-carbazol-9-yl）-N,N-diphenyl-9,9’-spirobi[fluoren]-2-amine（CzFA）双极性主体材料的红色电致磷光器件的光电特性。研究结果表明：将红色磷光染料iridium（Ⅲ）bis[2-methyldibenzo-（f,h）quinoxaline]（acetylacetonate）（Ir（MDQ）₂（acac））掺杂到CzFA主体材料中,以其制备的电致发光器件具有优良的特性,最大电流效率为27.8 cd/A,最大功率效率为21.8 lm/W,最大功率效率几乎是先前报道的主体材料为CBP器件（13.7 lm/W）的1.6倍。这种咔唑-螺二芴-二胺基团所组成的双极性主体材料对于提升磷光器件的性能起到了重要的作用。     

间隔层对双发光层白色有机电致发光器件性能的影响

采用蓝色bis (FIrpic)和黄色bis iridium(acetylacetonate) 两种磷光染料,制备了双发光层结构的白色有机电致发光器件,器件结构为ITO/TAPC (30 nm)/host: (t-bt)₂Ir(acac) /spacer (x nm)/host: FIrpic (15 nm, 8%)/Bphen (40 nm)/Mg∶Ag (200 nm)。分别选用p型1,1-bis cyclohexane (TAPC)和n型tris borane (3TPYMB)作为主体材料制备了两种类型的器件,通过在两个发光层之间加入一层较薄的间隔层进行器件优化。结果表明,加入间隔层之后,器件性能得到提高,获得了色稳定性较好的白光器件。当主体为TAPC时,使用间隔层后器件取得最大亮度为19 550 cd/m²,最大电流效率为8.3 cd/A;当主体为3TPYMB时,使用间隔层后器件的最大亮度为1 950 cd/m²,最大电流效率为30.7 cd/A。实验结果表明,器件性能的提高,是由于加入了间隔层之后载流子复合区域拓宽,促进了发光层中电子和空穴的平衡。     

基于溶液加工小分子材料发光层的有机-无机复合发光器件

报道了基于溶液加工有机小分子材料发光层、聚乙烯亚胺电子注入层的有机-无机复合发光器件. 优化了空穴传输层和磷光染料的掺杂浓度, 得到最佳发光效率的器件. 蓝光、黄光和红光器件的最大外量子效率为17.3%, 10.7% 和7.3%. 在发光亮度为1000 cd/m² 时, 蓝光、黄光和红光器件的外量子效率分别为17.0%, 10.6% 和5.8%, 器件效率下降较小. 原因在于同时采用空穴传输型和电子传输型的小分子材料作为共同主体材料, 器件具有较宽的载流子复合区域, 降低了三线激发态-三线激发态湮灭和三线激发态-极化子相互作用对器件发光效率的影响. 白光器件在亮度为1000 cd/m²时, 发光效率和功率效率为31 cd/A和 14.8 lm/W. 器件的色度为(0.32, 0.42), 色度比较稳定, 随电流的变化微小. 器件的效率较以往报道的有机-无机复合发光器件有显著的提高, 主要归因于在聚乙烯亚胺上能够制备特性良好的小分子材料薄膜, 以及小分子主体材料拥有较高的三线态能量和平衡的载流子传输特性, 能够获得高效的磷光发射.     

基于混合主体结构的溶液法制备的高效蓝色磷光OLED

为了提高蓝色有机发光二极管的效率,本文借助溶液法采用TcTa和CzSi混合主体,制备了蓝色磷光有机发光二极管（PHOLEDs）。此外,针对三种电子传输材料Tm3PyP26PyB、TmPyPB和TPBi进行了优选,以进一步优化器件的效率。本文通过优化混合主体材料的掺杂比例和电子传输材料的选择,不断提高器件的效率。最终,当TcTa∶CzSi的掺杂比为6∶1、电子传输层TPBi为70 nm时器件性能最优,其最大亮度(B_max)、电流效率(CE_max)、功率效率(PE_max)和外量子效率(EQE_max)分别为6 662 cd·m^-2、39.40 cd·A^-1、23.33 lm·W^-1和19.7%。此外,即使在1 000 cd·m^-2的实际亮度下,电流效率和外量子效率仍高达33.43 cd·A^-1和16.7%。     

铱金属配合物磷光材料掺杂聚合物体系的电致发光特性

通过对一种新型贵金属铱的配合物磷光材料(pbi)₂Ir(acac)与咔唑共聚物进行物理掺杂, 制备了结构为indium-tin oxide(ITO)/poly(N-vinylcarbazole)(PVK): (pbi)₂Ir(acac)(x)/2,9-dimethyl-4,7-diphenyl-1,10-phenan throline(BCP)(20nm)/8-Hydroxyquinoline aluminum(Alq₃)(10nm)/Mg:Ag的聚合物电致磷光器件,研究了磷光聚合物掺杂体系在低掺杂浓度时(0.1%和0.5%(质量百分数,全文同))的光致发光(PL)和电致发光(EL)特性. 结果表明, 该掺杂体系的PL光谱和EL光谱中均同时存在主体材料PVK与磷光客体(pbi)₂Ir(acac)的发光光谱, 但主客体的发射强度不同,推测该掺杂体系在电致发光条件下, 同时存在主体材料到客体的不完全的能量传递和载流子直接俘获过程. 磷光掺杂浓度为0.1%的器件在19V电压下实现了白光发射, 色坐标为(0.32, 0.38), 掺杂浓度为0.5%的器件在20.6V电压下的最大发光亮度为11827 cd·m^-2, 而在13.4V电压下的最大流明效率为4.13 cd·A^-1. 关键词： 有机电致发光器件 铱配合物磷光 聚合物掺杂     

基于1,3,5-tri(9H-carbazol-9-yl)benzene 主体材料的高效蓝色电致磷光器件

以1,3,5-tri(9H-ctarbazol-9-yl)benzene(TCzP)为主体材料,制备了FIrpic掺杂的高效有机电致蓝光双发光层器件,最大亮度为11957 cd/m2;最大电流效率为18.8 cd/A;色坐标为(0.17,0.37);光谱峰值位于472nm,在496 nm处有一肩峰;即使在1 000cd...     

空穴传输层掺杂SrF2的高效率蓝色磷光OLED器件

通过在OLED器件的空穴传输层中掺杂不同比例的SrF2制作出了高效率蓝色磷光OLED器件.这种器件能有效提高蓝色磷光OLED器件的空穴注入与传输特性,降低器件的的工作电压,提高流明效率(19.11m/W)、电流效率(26.9 cd/A)以及亮度(22 220 cd/m2),和未经掺杂的参比器件相比,分别提高了85.4％...     

中间层对白色全磷光有机电致发光器件性能的影响

制备了基于蓝色磷光材料bis[3,5-difluoro-2-（2-pridyl）phenyl-（2-earboxypyribyl）iridumⅢ]（FIrpic）、红色磷光材料bis（2-methyldibenzo [f,h]quinoxaline）（acetylacetonate）iridium（Ⅲ）（Ir（MDQ）₂acac）的双波段白光有机电致发光器件。蓝色磷光材料FIrpic被掺杂在一种宽带隙的主体材料1,3-bis（triphenylsilyl）benzene（UGH3）之中,红色磷光材料Ir（MDQ）₂acac被掺杂在主体材料4,4',4"-tris（carbazol-9-yl）triphenylamine（TCTA）之中,并在两发光层之间加入一种宽带隙的空穴传输材料1,3-bis（carbazol-9-yl）benzene（mCP）作为中间层。制备的器件结构为ITO/NPB（40 nm）/TCTA：Ir（MDQ）₂acac 7%（10 nm）/mCP（x nm）/UGH3：Firpic 8%（30 nm）/BPhen（30 nm）/LIF（0.8 nm）/AL（200 nm）。实验结果表明,中间层的加入促进了发光层中电子和空穴的平衡并抑制了发光层之间的能量转移。加入适当厚度的中间层之后,器件的性能得到了明显的提升,相比于无中间层器件,最高电流效率由3.4 cd/A提高到13.2 cd/A。     

基于mCP与UGH2为母体的双发光层高效率蓝色磷光OLED

以9,9'-(1,3-苯基)二-9H-咔唑(m CP)和1,4-二(三苯甲硅烷基)苯(UGH2)为母体,将常用的蓝光染料二(3,5-二氟-2-(2-吡啶)苯基-(2-吡啶甲酸根))合铱(Ⅲ)(FIrpic)掺入这两种母体材料中,制得具有双发光层结构的蓝色磷光有机电致发光器件,并对整个物理机制进行了阐述。该器件较基于m CP或UGH2为母体的单发光层器件有着更高的器件效率。器件的最大电流效率、功率效率、外量子效率分别为21.13 cd/A、14.97 lm/W、10.56%。器件亮度从100 cd/m2到3 000 cd/m2时,效率滚降为34.2%。     

Enhanced Green Electrophosphorescence from Oxadiazole-Functionalized Iridium Complex-Doped Devices Using Poly（9,9-Dioctylfluorene） Instead of Poly（N-Vinylcarbazole） as a Host Matrix

Optoelectronic properties of the oxadiazole-functionalized iridium complex-doped polymer light-emitting devices （PLEDs） are demonstrated with two different polymeric host matrices at the dopant concentrations 1-8%. The devices using a blend of poly（9,9-dioctylttuorene）（PFO） and 2-（4-biphenyl）-5-（4-tert-butylphenyl）-1,3,4-oxadiazole （PBD） as a host matrix exhibited a maximum luminance efficiency of 11.3 cd/A at 17. 6 mA/cm^2. In contrast, the devices using a blend of poly（N-vinylcarbazole） （PVK） and PBD as a host matrix reveal only a peak luminance efficiency of 6.Scd/A at 4.1 mA/cm^2. The significantly enhanced electrophosphorescent emissions are observed in the devices with the PFO-PBD blend as a host matrix. This indicates that choice of polymers in the host matrices is crucial to achieve highly efficient phosphorescent dye-doped PLEDs.     

High-efficiency blue and white phosphorescent organic light-emitting devices

We have significantly improved the efficiency of blue and white phosphorescence from organic light-emitting devices (OLEDs) based on phosphorescent iridium complexes. To improve the emission efficiency, 4,4^′-Bis(9-carbazolyl)-2,2^′-Dimethyl-biphenyl (CDBP), which has a high triplet energy, was used as the carrier-transporting host for the emissive layer. The blue phosphorescent OLED exhibited a maximum external quantum efficiency of 10.4%, which corresponds to a current efficiency of 20.4 cd/A. This result can be explained as due to the efficient confinement of triplet energy on blue phosphorescent molecules, which is consistent with the results of transient photoluminescence experiments. The white phosphorescent OLED with greenish-blue and red emissive layers exhibited a maximum external quantum efficiency of 12% and a luminous efficiency of 18 cd/A. This is primarily attributed to the improvement of greenish-blue emission efficiency as well as the emission efficiency of the blue phosphorescent OLED.     

Efficient Solution-Processed Blue Electrophosphorescent Devices Based on a Novel Small-Molecule Host

Efficient blue small molecular phosphorescent fight-emitting diodes with a blue phosphorescent dye bis（3,5- difluoro-2-（2-pyridyl）-phenyl-（2-carboxypride） iridium （Ⅲ） （Flrpic） doped into a novel small-molecule host 9,9- bis[4-（3,6-di-tert-butylcarbazol-9-yl）phenyl] fluorene （TBCPF） as the light-emitting layer have been fabricated by spin-coating. The host TBCPF can form homogeneous amorphous films by spin-coating and has triplet energy higher than that of the blue phosphorescent dye Flrpic. All the devices with different Flrpic concentration in the emitting layer give emission from Flrpic indicating complete energy transfer from TBCPF to Flrpic. The device shows the best performance with a peak brightness of 8050 cd/m^2 at 10.2 V and the maximum current efficiency up to 3.52 cd/A, when the Flrpic doped concentration is as high as 16%.     

High power efficiency in single layer blue phosphorescent organic light-emitting diodes

High efficiency single layer blue phosphorescent organic light-emitting diodes (PHOLEDs) without any charge transport layer were developed. A mixed host of spirobifluorene based phosphine oxide (SPPO13) and 1, 1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) was used as the host in the emitting layer. A high maximum external quantum efficiency of 15.8% and a quantum efficiency of 8.6% at 1000 cd/m² were achieved in the single-layer blue PHOLEDs without any charge transport layer. The maximum power efficiency and power efficiency at 1000 cd/m² were 31.4 and 16.9 lm/W, respectively.     

溶液法制备基于新型热交联主体材料OLED器件的研究

为了得到溶液法制备的高性能的OLED器件,基于咔唑和1,2,4-三氮唑基团及可热交联的苯乙烯基团,设计并合成了可热交联的主体材料VB-CzTAZ。测试结果表明,VB-CzTAZ具有很好的热稳定性(Td:323℃),把该材料溶于氯苯旋涂成膜,该膜在手套箱中190℃下发生热交联。不同溶剂的薄膜清洗实验表明,热交联后的VB-CzTAZ具有优秀的抗溶剂性。基于VB-CzTAZ溶液法制备的绿光磷光器件,最低启动电压为5.1 V,最大亮度为2 404 cd/m~2,最大电流效率为4.3 cd/A,表明该交联材料可以用于溶液法制备多层OLED器件。     

A Mixed Host Emitting Interlayer Based on CBP:TPBi in Green Phosphorescent Organic Light-Emitting Diodes

A series of green phosphorescent organic light-emitting diodes based on bipolar-transporting material 4,4'-bis-(carbazol-9-yl) biphenyl(CBP) are prepared.We insert a mixed host emitting interlayer(CBP_X:electrontransporting material 1,3,5-tris(N-phenylbenzimidazole-2yl)(TPBi)_(1-x)) in the middle of the emitting layer,and the best performance appears when x is 2/3.The position of this interlayer can also affect the performance of phosphorescent organic light-emitting diodes.When this interiayer is ciose to the side of the electron transporting layer,the maximum value of luminance,the current efficiency and the power efficiency are 34090 cd/m~2 at 12 V,60.6cd/A and 56.6lm/W,respectively.     

Bright white light electroluminescent devices based on efficient management of singlet and triplet excitons

Efficient and bright white organic light-emitting devices (WOLEDs) based on phosphor sensitized fluorescence are improved by using an unusual device structure, in which phosphorescent emissive layer is sandwiched between two blue fluorescent doped ones. This architecture allows for resonant energy transfer from both the host singlet and triplet energy levels that minimizes exchange energy losses. Thus, a WOLED with a maximum luminous efficiency of 11.63 cd/A, a maximum power efficiency of 7.37 lm/W, a maximum luminance of 31,770 cd/m², and Commission Internationale de L’Eclairage coordinates of (0.34, 0.36) is achieved.