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171.
白色磷光OLEDs的制备及性能研究 总被引:3,自引:3,他引:0
采用蓝色、黄色磷光混色的发光方式实现白光有机电致发光器件(OLEDS),其中黄色发光层由红色和绿色磷光材料混合而成,器件的结构为ITO/MoO3(30nm)/NPB(40nm)/mCP:FIrpic(8%)(50nm)/CBP:R-4B(1%):GIrl(14%)(xnm)/BCP(10nm)/AlQ(40nm)/LiF(1nm)/Al(100nm)(x=2,3,4,5,6nm)。对器件的效率、亮度等对比发现,当x=5nm时,器件的性能最佳,最大亮度为9 471cd/cm2,效率为23.5cd/A,色坐标(0.32,0.35)。实验表明,影响器件色稳定性和效率低的原因是电子和空穴迁移随驱动电压变化响应不一致引发激子复合区域的移动。 相似文献
172.
基于不同浓度FeCl3掺杂的4,4′-N,N′-二咔唑基联苯(CBP)设计制作了一系列的单空穴有机电致发光器件(OLED),采用空间电荷限制电流法估算了具有不同浓度FeCl3掺杂的CBP的空穴迁移率,并与OLED中常用的空穴传输材料N,N′-二苯基-N,N′-(1-萘基)-1,1′-联苯-4,4′-二胺(NPB)进行了比较研究。结果表明,FeCl3掺杂CBP可以极大地提高CBP薄膜的空穴迁移率,当FeCl3的浓度为12%时空穴迁移率最大,在电场强度为0.5MV/cm的条件下迁移率为4.5×10-5cm2/V·s,即使在零电场条件下迁移率依然高达2.2×10-5 cm2/V·s,近似为常用空穴传输材料NPB空穴迁移率的4倍。用CBP∶12%FeCl3做空穴传输层,制备了OLED器件,最大亮度为68468cd/m2,相对于采用NPB做空穴传输层的参比器件提高了97%,最大电流效率为31.28cd/A,比参比器件提高了23%。器件亮度和效率的提高归因于空穴传输性能的改善,使得器件中载流子的传输更为平衡,从而提高了激子形成的几率,且减少了激子-极化子之间的淬灭。 相似文献
173.
174.
Tandem organic light-emitting devices (OLEDs) were fabricated with a hybrid organic charge generation layer (CGL) composed of bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) doped 1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene (TPBi), 1,3-bis(cabazol-9-yl)benzene (mCP), and 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) in an attempt to enhance their current efficiency. While the operating voltage of the tandem OLEDs with a hybrid structure composed of BEDT-TTF-doped TPBi, mCP, and a HAT-CN CGL at 10 mA/cm2 was 1 V lower than that of the tandem OLEDs with a typical CGL composed of BEDT-TTF-doped TPBi and a HAT-CN, the corresponding the current efficiency of the tandem OLEDs with a hybrid CGL at 10 mA/cm2 was 2.9 cd/A higher than that of the tandem OLEDs with a typical CGL. The increase in the current efficiency and the decrease in the operating voltage of the tandem OLEDs with the hybrid CGL were attributed to enhanced electron injection due to the insertion of the mCP layer into the hybrid CGL. 相似文献
175.
《Organic Electronics》2014,15(1):57-64
Diphenylamino- and triazole-endcapped fluorene derivatives which show a wide energy band gap, a high fluorescence quantum yield and high stability have been synthesized and characterized. Single-layer electroluminescent devices of these fluorene derivatives exhibited efficient deep blue to greenish blue emission at low driving voltage. The single-layer OLED of PhN-OF(1)-TAZ shows a maximum current efficiency of 1.54 cd/A at 20 mA cm−2 with external quantum efficiency (EQE) of 2.0% and CIE coordinates of (0.153, 0.088) in deep blue region, while the single-layer device of oligothienylfluorene PhN-OFOT-TAZ shows a maximum brightness of 7524 cd/m2 and a maximum current efficiency of 2.9 cd/A with CIE coordinates of (0.20, 0.40) in greenish blue. 相似文献
176.
《Organic Electronics》2014,15(7):1440-1447
High molecular weight and non-crosslinking conjugated donor–acceptor copolymers with chlorine on the backbones were straight forward synthesized for the first time under Stille condensation reaction by using the different reaction activities between chlorine and bromine atoms. The chlorine-bearing polymers exhibited much lower LUMO, larger Stokes shift and lower self-absorption compared with the non-chloride analogue, for the electron affinity and large steric hindrance of chlorine atoms. Deep red to NIR emission centered at 698 nm was obtained with brightness about 1500 cd/m2 and centered at 708 nm was obtained with brightness over 400 cd/m2 based on dopant/host system. 相似文献
177.
《Organic Electronics》2014,15(7):1465-1475
The flexible top-emitting white organic light-emitting diode (FTEWOLED) with a very high efficiency but a significant color alteration is achieved with a blue/red/blue sandwiched tri-emission-layer. The voltage-dependent recombination region alternation and the emission mechanism are systematically investigated through a delta-doping method and the time-resolved transient photoluminescence lifetime measurement. By locating the main exciton recombination region at the 4,4′,4″-Tris(carbazol-9-yl)-triphenylamine (TCTA) and 9,9-spirobifluoren-2-yl-diphenyl-phosphine oxide (SPPO1) interface, replacing the carrier-trapping red dopant guest with an orange guest that utilizes energy transfer mechanism, and using a P–I–N structure together with the FIrpic blue guest dopant to balance the electron and hole carriers, an extremely color stable and a very high efficient FTEWOLED is fabricated, with the resulting high current and power efficiencies of 22.7 cd/A and 14.27 lm/W, and a warm white illumination with a small chromaticity variation of (−0.0087, +0.0015) over a broad luminance range of more than four orders of magnitude. In addition, the performances can be further improved to 23,340 cd/m2, 24.49 cd/A and 15.39 lm/W with a slight concentration alteration of the orange emitter. 相似文献
178.
《Organic Electronics》2014,15(8):1717-1723
We have investigated the growth behavior and water vapor permeation barrier properties of cyclic chemical vapor deposition (C-CVD)-grown 10-nm-thick single layer of Al2O3. Al2O3 layers grown by C-CVD showed a high density of 3.298 g/cm3 and were amorphous without grain boundaries. A deposition rate of 0.46 nm/cycle was obtained. The C-CVD system was self-limiting, as in the case of atomic layer deposition, which enables precise control of the thickness of the Al2O3 layer. A water vapor transmission rate of 1.51 × 10−5 (g/m2)/day was obtained from a Ca degradation test performed at 85 °C and 85% relative humidity. Moreover, the performance of organic light-emitting diodes, passivated by a C-CVD-grown 10-nm-thick Al2O3 single layer, was not affected after 24,000 h of turn-on time; this is strong evidence that C-CVD-grown Al2O3 layers effectively prevent water vapor from diffusing into the active organic layer. 相似文献
179.
功能层厚度是影响有机电致发光器件出光效率的主要因素之一,故获得不同功能层厚度对器件出光特性的影响规律是制备高性能器件的重要基础. 本文基于薄膜光学原理、电偶极子辐射理论及Fabry-Pérot微腔原理,建立了结构为glass/ITO/N,N0-bis(naphthalen-1-yl)-N,N0-bis(phenyl)-benzidine(NPB)/tris(8-hydroxyquinoline)aluminum(Alq3)/molybdenum trioxide(MoO3)/NPB/Alq3/Al的叠层有机电致发光器件的光学模型,系统地研究了各个功能层厚度对叠层有机电致发光器件出光强度的影响,得到了功能层厚度对器件出光强度影响的规律. 该模型的建立与所获得的结果可对深入了解叠层有机电致发光器件的工作机理以及制备高性能的器件提供一定的帮助.
关键词:
叠层有机发光器件
出光特性
厚度
数值研究 相似文献
180.
本文详细测试了用RF-PECVD法制备的非晶硅碳薄膜发光二极管的光强电流特性和温度对器件发光强度的影响.在直流电流驱动下,器件的发光在注入电流1A/cm2左右趋于饱和,而在低占空比的脉冲电流驱动下器件的发光直至注入电流20A/cm2仍随电流近似线性增长,但提高环境温度发光随之下降.结合对器件受热情况分析表明,热致猝灭而非场致猝灭导致了器件在大电流下的发光饱和,并简要提出了改进器件散热的措施. 相似文献