一种叠层结构绿光有机电致发光器件

制备了叠层结构的绿光有机电致发光器件,采用电荷生成层将两个发光单元串接起来,各个发光单元之间互不影响,由两个发光单元分别发出的光叠加,得到高效率的绿光发射.     

叠层有机电致发光器件中电荷产生层的优化

叠层结构应用到有机电致发光器件中,可以显著的提高器件的性能,尤其是电流效率。在叠层结构中,电荷产生层发挥着及其重要的作用,因此对电荷产生层的优化具有重要的意义。我们通过一系列试验,确定了电荷产生层合理的参数为:由掺杂Li的BCP和V2O5层共同组成,其中BCP掺杂2%的Li,V2O5的厚度为30nm。     

高效率的白光有机电致发光器件

为了提高白光有机电致发光器件的发光效率和光谱稳定性,采用染料掺杂的方法,制备了多层结构白光有机电致发光器件。通过参数优化实现了非常好的白光发射,并表现出良好的光谱稳定性。器件的开启电压为5.1V,发光亮度达到10800cd／m^2,最大电流效率和功率效率分别是10.4cd／A和3.5lm／W。     

红色有机薄膜电致发光器件

研制了三种以 8-羟基金属螯合物 Mq3(M=Al,Ga,In)为基质、DCJTB为掺杂剂的红色有机电致发光器件 ,对比了不同掺杂浓度下的 Mq3的光致发光光谱、电致发光的亮度 -电压、亮度 -电流关系 ,从光谱重叠、能级匹配角度分析了不同基质对发光效率及色度的影响     

有机电致发光器件的研究进展

有机电致发光器件是近年来国际上研究的一个热点，发展非常迅速。该器件具有自发光、响应快、发光效率高、驱动电压低、能耗低、成本低等许多优点，因此它极有可能成为下一代的平板显示终端。概述了有机电致发光(EL)器件的结构、工作原理、目前研究进展状况、出现的问题以及发展趋势等。     

有机电致发光器件(OLED)

系统介绍了有机电致发光器件的器件结构与发光机理,从有机半导体的能带和OLED器件的结构,分析了载流子在有机物中传输,OLED发光过程,以及各有机薄膜层的作用,指出了如何提高器件的发光效率和提高器件性能的途径。最后概述了OLED器件的现状及发展前景。     

小分子有机电致发光材料研究进展

 有机电致发光器件（OLED）具有效率高、亮度高、驱动电压低、响应速度快以及能实现大面积光电显示等优点,因其在平板显示和高效照明领域具有极大的应用前景而引起广泛关注。在OLED的制备及优化中,有机电致发光材料包括小分子和聚合物的选择至关重要,其中有机小分子发光材料具有确定的相对分子质量、化学修饰性强、选择范围广、易于提纯、荧光量子产率高以及可以产生红、绿、篮等各种颜色光等优点,一直受到国内外学者的广泛重视。本文综述了近年来国内外有机电致发光小分子发光材料的研究状况,对有机小分子电致发光材料进行分类和评述,并简要介绍了小分子OLED的应用前景和发展趋势。     

有机电致发光白光器件的研究

白光有机电致发光器件在显示领域有着极大的应用前景,受到人们广泛的关注.通过对白光有机电致发光器件的结构、工作原理、实验的可行性分析、工艺流程、存在的问题等方面进行了分析,对器件结构进行了优化设计,确定了合理的技术路线,提高白光电致发光器件中各成分的发光效率,从而得到了一种较为理想的有机白光电致发光器件.     

有机聚合物及小分子材料的电致发光器件

论述了有机聚合物及小分子材料的电致发光原理,发光二极管的结构及影响器件稳定性,寿命的原因,总结了目前该领域所取得的成果,展望了下世纪有机发光材料的应用前景和商业化可能性。     

紫外LED研究进展

氮化物紫外LED的发光波长覆盖210-400 nm的紫外波段,可广泛应用于工业、环境、医疗和生化探测等领域.近年来紫外LED的技术水平发展迅速,器件性能不断提升.由于高Al组分AlGaN材料的固有特性,目前深紫外LED的外量子效率和功率效率仍有大量提升空间.综述了近年来AlGaN基紫外LED的研究进展,阐述了限制其性能...     

Dependence of the stability of organic light-emitting diodes on driving mode

We investigated the effects of pulsed current (PC) and direct current (DC) driving modes on the stability of organic light-emitting diodes with and without hole-injection layers (HILs).Two different HIL materials were used:copper phthalocyanine (CuPc) and 4,4’,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MDTATA).It was found that the half-lives of devices using PC driving modes were different from those of comparable devices using DC driving modes.For the devices without HILs,with CuPc HILs and with MTDATA HILs,the half-lives of the devices were changed by factors of 1.91,1.41 and 0.86,respectively,when operated in PC rather than DC driving modes.Our analysis of the electrical characteristics of the corresponding hole-only devices showed that the number of holes injected into devices was greatly reduced by inserting an m-MTDATA layer compared with other designs.The results indicate that different ratios of injected electrons and holes can be obtained in these devices.Moreover,these ratios play a dominant role in the dependence of the stability of the device on the driving mode.     

Stability study of saturated red polymer light-emitting diodes

Saturated red polymer light-emitting diodes have been fabricated with a single emitting polymer blend layer of poly[2-(2-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] (MEH-PPV) and poly[9,9-dioc- tylfluorene-co-4,7-di-2-thienyl-2,1,3-benzothiadiazole] (PFO-DBT15). Saturated red emission with the Commission Internationale de l’Eclairage (CIE) coordinates of (0.67, 0.33) was obtained. The device stability was investigated. The results showed that energy transfer occurred from MEH-PPV to PFO-DBT15, and MEH-PPV improved the hole injection and transportation.     

有机掺杂红色发光二极管的特性研究

研究了不同掺杂浓度掺杂Alq3：DCM体系有机发光二极管的电致发光（EL）特性,根据实验结果,指出器件的EL发射峰值跟作为受体的DCM在给体Alq3中的掺杂浓度有关,应用Forster能量传递理论对其机理进行了解释。     

有机发光二极管中不同金属电极引起的奇特磁效应

采用三类金属阴极材料Ca,Al和Cu（Au）通过分子束沉积和电子束加热方式制备了有机发光二极管ITO/CuPc/NPB/Alq3/金属阴极,并在300,200,150,100,50和15K6个温度下,分别测量了不同电极器件的发光随外加磁场的变化（即Magneto-ElectroLuminescence,MEL）.在室温300K下,发现Ca,Al和Cu（Au）电极器件的MEL在低场（0B50mT）均表现为快速上升;但随磁场（B〉50mT）的进一步增大,Ca和Al电极器件的MEL缓慢变大并逐渐趋于饱和,且与阴极的制膜方式无关;而采用电子束加热方式制备的Cu（Au）电极器件,其MEL却表现出高场缓慢下降;且温度越低,该类Cu电极器件MEL的高场下降更为显著.实验研究表明,Ca和Al电极器件的MEL主要是由超精细耦合作用随外加磁场变化引起的.但电子束加热方式制备的Cu（Au）电极器件的MEL除了超精细耦合作用引起的低场快速上升外,其高场下降的可能机制则是：Cu（Au）电极器件中电子-空穴对的俘获区（e-hCapture Zone）靠近阴极界面,相比较于热蒸发的方式,电子束蒸发的方式更容易使重金属Cu（Au）原子得到更高的能量,使其渗透进相邻的有机层Alq3中,Cu（Au）原子的强自旋轨道耦合作用导致电子-空穴对发生自旋翻转,此为MEL出现高场下降的原因.     

Spectral variation of light-emitting diodes based on organic molecules doped polymer

Organic light-emitting diodes based on naphthylimine-gallium complexes doped into a PPV derivative have been fabricated by a spin coating method. Color variation from green to blue with increase of the applied voltage has been observed. And the electroluminescent intensity of the blend samples is much stronger than that of the samples containing the complexes only. The results have been attributed to the variation of the recombination zone and the charge transfer between the materials. The process of the charge transport has been analyzed in detail.     

Flexible organic light-emitting diodes with poly-3, 4-ethylenedioxythiophene as transparent anode

The flexible oragnic light-emitting diodes (OLEDs) fabricatedon poly-3, 4-ethylenedioxythiophene/polystyrenesulfonate (PEDOT/PSS) coated substrates were demonstrated. How the fabricating processes and the device structure will affect the device performance was studied and the atomic force microscopy was employed to analyze the mophorlogy of the conducting polymer anode. Under optimized conditions, flexible OLEDs with PEDOT anode showed the brightness up to 2760 cd/m² and maximum external quantum efficiency of 1.4%. These data are comparable to those of conventional flexible OLEDs with ITO anode.     

High-efficiency conjugated-polymer-hosted blue phosphorescent light-emitting diodes

Highly-efficient blue phosphorescent light-emitting diodes were fabricated based on a conjugated-polymer host by doping bis(2-(4,6-difluorophenyl)-pyridinato-N,C2’) picolinate(FIrpic) into poly(9,9-dioctylfluorene)(PFO).Previously,conjugated polymers were not considered as potential hosts for blue phosphorescent dyes because of their low-lying triplet energy levels.Energy back transfer would occur and lead to poor luminescent efficiency in both photoluminescence(PL) and electroluminescence(EL) processes.However,by inserting a hole-transporting layer of poly(N-vinylcarbazole)(PVK),the energy back transfer was suppressed.At low FIrpic-doping concentrations,PFO emissions were completely quenched;with 8 wt% FIrpic,a maximum luminous efficiency of 11.5 cd/A was achieved.