共查询到18条相似文献,搜索用时 46 毫秒
1.
为了增加电子注入,蓝色有机电致发光器件中通常包含一层由发绿光的Alq组成的电子传输层,因此器件的发光常常不可避免地要出现Alq本身的发光从而影响器件的发光色纯度.在以胺类衍生物(N,N'- diphenyl-N,N'-bis(3-methylphenyl)-1,1'biphenyl-4,4'diamine,TPD)为空穴传输层,DSA衍生物(4,4'-bis (2,2-diphenylvinyl)-1,1'-biphenyl, DPVBi)为发光层,当用Liq为电子注入层与Al结合构成复合电极时所制备的双层单异质结蓝色有机电致发光器件中由于去除了Alq而得到色度纯正的DPVBi的发光,同时又保持了较高的发光效率. 相似文献
2.
具有多层薄膜结构,发射鲜蓝色光的有机电致发光(EL)器件已经制成并为选择蓝色发光材料制定了二个经验性指南。要获到具有高 EL 效率的 EL 器件,关键是发射层要有优异的成膜能力以及发射极与载流子输运材料的适当组合,避免形成激态复合物。在我们的有机电致发光器件中,有一个器件在电流密度为100mA/cm~2,直流驱动电压为10V 时,蓝光发射亮度达700cd/m~2。 相似文献
3.
4.
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. 相似文献
5.
以联苯乙烯衍生物(4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl,DPVBi)和红荧烯(5,6,11,12-tetraphenylnaphthacene,Rubrene)分别为蓝色、橙色发射体,通过超薄插入的方法在DPVBi中插入一层Rubrene制备了结构简单的非掺杂型蓝色、橙色混合有机电致发光器件(OLED)。结果表明,器件电压对色度的影响规律随插入位置不同而变。当器件发光中以蓝色为主或以橙色为主时器件色坐标随电压的变化较小,而当器件中蓝色和橙色发射成分较为均衡时色坐标随电压的变化较大。其原因可归于电压对蓝色和橙色发射具有不同的影响。 相似文献
6.
高效率非掺杂型白色有机电致发光器件 总被引:1,自引:0,他引:1
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). 相似文献
8.
将一类有机配合物NGC溶于氯仿中,加入少量PMMA后用旋涂法制得单层薄膜电致发光器件,得到了稳定的蓝色发光。在这些配合物中掺入适量PPV衍生物,可将蓝色发光提高几十倍,这归结于载流子的平衡注入。 相似文献
9.
10.
热处理提高蓝色有机电致发光器件性能的研究 总被引:3,自引:1,他引:3
选取梯形次对苯基聚合物LPPP和小分子Ya二唑材料OXD-7分别作为具有空穴转移特性的发光层材料及电子输运材料制备了蓝色有机电致发光(OEL)器件,采用热处理方法显著地提高了其发光性能,其最佳热处理条件为:真空中,170℃,1h。初步分析了热处理提高器件发光性能的原因,主要有两个因素:高温作用促进异质结的形成;热处理改善器件阴极/有机薄膜界面的接触状况,有效地减少器件工作中产生的黑斑。 相似文献
11.
有机电致发光的效率 总被引:5,自引:3,他引:2
描述了评价有机电致发光性能的重要指标--发光效率问题,从发光机制考虑,一般常用外量子效率和内量子效率来评价。外量子效率是有机电致发光器件输出光子数与注入电子数之比;内量子效率是产生在器件内部的光子数与液入电子数之比,对于光子能否输出到器件外部无关紧要。评价器件性能还有一些其他效率评价方法,如能量效率,功率效率等,特别是外功率效率(1m/W),电流效率(cd/A)也常常用于表征有机电致发光性能,但它们与发光光谱的视觉灵敏度有关,对紫外外辐射器件不适用,另外,利用三重态激子发射可以提高EL器件效率,理论上可达100%,器件结构及材料对器件外量子效率影响至关重要。 相似文献
12.
13.
掺杂型有机电致发光器件中载流子的俘获机制 总被引:3,自引:0,他引:3
掺杂型有机电致发光器件中,掺杂剂的发光来源于基质的能量传递或者来源于掺杂剂对载流子的俘获,也有可能两种机制同时存在。为了揭示掺杂型器件发光中究竟哪种机制占主导,以联苯乙烯衍生物(amino substituteddistyrylarylenederivative,BCzVB)掺杂4,4‘ 双(9 咔唑基) 1,1‘ 联苯(4,4‘ N,N‘ dicarbazole biphyenyl,CBP)为发光层的器件中,通过电流 电压特性的分析表明器件的发光主要来源于载流子俘获机制。光致发光与电致发光对比分析也表明,器件的发光过程中载流子俘获机制起了主导作用。 相似文献
14.
制备了由有机空穴传输层和有机发光层组成的双层有机薄膜电致发光器件,器件的发光亮度相对于单层器件有了很大的提高。并用不同深度区域的掺杂方法,对其电致发光机理作了探讨。对单、双层器件的不同的亮度电流关系、不同的发光区域进行了分析和讨论. 相似文献
15.
16.
17.
Chang‐Gua Zhen Yan‐Feng Dai Wen‐Jin Zeng Zhun Ma Zhi‐Kuan Chen John Kieffer 《Advanced functional materials》2011,21(4):699-707
Based on the results of first‐principles calculations of the electronic properties of blue light‐emitting materials, the molecular structures of oligofluorenes are optimized by incorporating electron‐withdrawing groups into the molecules to balance hole and electron injection and transport for organic light‐emitting diodes (OLEDs). The result is a remarkable improvement in the maximum external quantum efficiency (EQE) of the undoped device from 2.0% to 4.99%. Further optimization of the device configurations and processing procedures, e.g., by changing the thickness of the emitting layer and through thermal annealing treatments, leads to a very high maximum EQE of 7.40% for the undoped sky‐blue device. Finally, by doping the emitter in a suitable host material, 4,4’‐bis(carbazol‐9‐yl)biphenyl (CBP), at the optimal concentration of 6%, pure blue emission with extremely high maximum EQE of 9.40% and Commission Internationale de l’Eclairage (CIE) coordinates of (0.147, 0.139) is achieved. 相似文献
18.
Efficient Nondoped Blue Fluorescent Organic Light‐Emitting Diodes (OLEDs) with a High External Quantum Efficiency of 9.4% @ 1000 cd m−2 Based on Phenanthroimidazole−Anthracene Derivative 下载免费PDF全文
Xiangyang Tang Qing Bai Tong Shan Jinyu Li Yu Gao Futong Liu Hui Liu Bing Yang Feng Li Ping Lu 《Advanced functional materials》2018,28(11)
Organic light‐emitting diodes (OLEDs) can promise flexible, light weight, energy conservation, and many other advantages for next‐generation display and lighting applications. However, achieving efficient blue electroluminescence still remains a challenge. Though both phosphorescent and thermally activated delayed fluorescence materials can realize high‐efficiency via effective triplet utilization, they need to be doped into appropriate host materials and often suffer from certain degree of efficiency roll‐off. Therefore, developing efficient blue‐emitting materials suitable for nondoped device with little efficiency roll‐off is of great significance in terms of practical applications. Herein, a phenanthroimidazole?anthracene blue‐emitting material is reported that can attain high efficiency at high luminescence in nondoped OLEDs. The maximum external quantum efficiency (EQE) of nondoped device is 9.44% which is acquired at the luminescence of 1000 cd m?2. The EQE is still as high as 8.09% even the luminescence reaches 10 000 cd m?2. The maximum luminescence is ≈57 000 cd m?2. The electroluminescence (EL) spectrum shows an emission peak of 470 nm and the Commission International de L'Eclairage (CIE) coordinates is (0.14, 0.19) at the voltage of 7 V. To the best of the knowledge, this is among the best results of nondoped blue EL devices. 相似文献