基于银纳米线透明电极制备柔性电致变色器件

透光率可调节的电致变色(EC)器件在光电子领域有着巨大的应用潜力。目前绝大多数电致变色器件都是基于氧化铟锡(ITO)透明电极和无机氧化钨(WO3)电致变色材料,机械柔性较差。本文采用多元醇法合成的银纳米线(AgNWs),有机电致变色材料(P3HT)和(PEDOT∶PSS)替代ITO与WO₃制备柔性EC器件,并利用高透光率的ZnO涂层增强AgNWs与柔性基底的粘附性,以及改善AgNWs之间的节点接触从而优化AgNWs网格的相互连接,使得AgNWs柔性透明电极的表面电阻由69.9 Ω/□减小为45.8 Ω/□。另外通过在PVA水溶液中掺入LiBF₄进行冷冻,得到离子导电率为1.53×10^-2 S/cm的凝胶电解质,利用该高导电率的凝胶电解质充当对电极层简化EC器件,使得EC器件整体具有更高的透光率,制备出最大光调制范围为37.8%的PEDOT∶PSS EC器件和最大光调制范围为17.7%的P3HT EC器件。最后利用中国传统毛笔书写和大面积丝网印刷的方式制备个性化图案的PEDOT∶PSS EC器件,具有很好的显示效果。     

柔性有机电致发光器件制备及光电性能研究

制作了结构为ITO／PVK：TPD／Alq3／Al、分别以PET为衬底的柔性的和以玻璃为衬底的普通的有机电致发光二极管（OLED）,对两种器件的电流密度-电压曲线、光电流-电压曲线及量子效率-电流密度曲线进行了测量与分析。结果表明,它们的光电特性非常接近,但柔性OLEDs（FOLEDs）的开启电压略高;在20V电压驱动下,FOLEDs的亮度达到1000cd／m^2,量子效率为0．27％。对器件进行了抗弯折性能的测试。     

铜纳米线柔性透明导电薄膜的制备和性能研究

为寻找替代硬质氧化铟锡的新型柔性透明导电薄膜,采用液相还原法制备了大长径比的铜纳米线,并利用喷涂法实现铜纳米线柔性透明导电薄膜的制备。采用透射电子显微镜、扫描电子显微镜、X射线衍射仪对形貌和相结构进行了分析,并用紫外可见分光光度计和四探针测试仪分别对铜纳米线柔性透明导电薄膜的电学性能和光学性能进行了表征测试。结果表明,铜纳米线直径约为40 nm,长度为10～20μm,具有高长径比、分散性好、形貌规整的特点。同时,铜纳米线薄膜的电学和光学性能优异,方阻约为100Ω/,在550 nm处的光透射率为82%左右。该薄膜还具有较好的温度稳定性,耐温可达110℃,且其方阻在不同弯折程度下变化不大,具有良好的抗弯折性,可用于柔性可穿戴电子产品。     

基于石墨烯的柔性黄光有机发光二极管制备与性能

采用喷涂技术制备了石墨烯/PEDOT:PSS复合透明导电薄膜,并在此基础上制备了柔性黄光OLED器件。通过设计DPVBi/Rubrene/DPVBi势阱结构,可以实现电荷的有效陷获,获得稳定明亮的黄光发射。实验结果表明,适当增加发光区的厚度,可以提升器件的发光效率和稳定性,在12 V时器件的效率为0.9 cd/A。该柔性黄光OLED器件在反复弯曲测试中表现出了良好的发光稳定性,发光效率没有产生明显变化。     

三氧化钼修饰银透明电极的光电性能及其应用研究

银(silver,Ag)纳米薄膜具有优异的导电性、延展性、易制备等优点,是极具潜力的柔性透明电极材料。通过真空热蒸镀制备不同厚度的银薄膜(6 nm、10 nm、14 nm、18 nm、20 nm、24 nm),由于光散射和光吸收的共同作用,其透过率随厚度的增加呈先减小、再增加、再减小的趋势,厚度为18 nm时最优,最高透过率约60%;而面电阻则随厚度的增加逐渐减小。为提升银膜的透过率,引入高折射率(2.1)电介质三氧化钼(molybdenum trioxide,MoO₃)对银膜进行修饰,制备了MoO₃/Ag/MoO₃(MAM)多层膜。结果表明:引入MoO₃可以平滑银膜表面,降低面电阻,并改善电导率;更重要的是“MoO₃/Ag”界面处会发生折射率耦合,大大提升多层膜的整体透过率,透过率普遍增加至少10%。当银层的厚度为14 nm时,MAM多层膜的透过率最优,可接近70%。最后,以银作为透明阴极,成功制备了双侧发光的绿光有机发光二极管(organic light-emitting diode,OLED)。     

电纺掩模制备铜纳米线网络透明电极

通过真空蒸镀技术、静电纺丝技术和湿法腐蚀法成功制备出铜纳米线网络透明电极.首先优化纺丝条件,制备出均匀的聚丙烯腈(PAN)纳米纤维,然后将PAN纳米纤维作为掩模腐蚀铜膜得到铜纳米线网络透明电极.通过对纺丝时间、纺丝接收取向、蒸气处理时间和湿法腐蚀时间等制备条件进行优化,得到表面光滑连续、形貌良好的铜纳米线网络透明电极....     

银纳米线复合透明电极在太阳能电池中的应用

正近年来,银纳米线透明电极技术引起了广泛关注,它有希望替代通用的铟锡氧化物(ITO)透明电极,广泛地应用于光电技术相关领域。介绍一种基于银纳米线和金属氧化物复合结构的透明电极技术,并将其成功地应用在有机聚合物光伏器件和无机CIGS薄膜光伏器件中,所实现的器件性能可以与基于ITO透明电极的器件性能相媲美。     

用于OLED的碳纳米管

首先,介绍了传统柔性有机发光二极管(FOLED)的基本结构及缺点.其次,对氧化铟锡(ITO)玻璃应用于FOLED生产的局限性进行了阐述.然后将碳纳米管(CNT)与ITO薄膜进行了对比,对碳纳米管应用于FOLED制备的可行性进行了分析,并对碳纳米管生产及器件的制备进行了说明.对碳纳米管的分类以及分离进行了简要阐述,着重分...     

ZnSnO/AgNW双层透明电极的制备及性能研究

利用旋涂银纳米线和磁控溅射ZnSnO薄膜相结合的方法,实现了高性能ZnSnO/AgNW双层透明电极的制备。采用X射线衍射仪和扫描电子显微镜对电极的结构和形貌进行了表征分析,利用紫外可见分光光度计和四探针测试仪分别对ZnSnO/AgNW双层透明电极的电学和光学性能进行了表征。结果表明,制备的ZnSnO/AgNW双层透明电极具有优异的电学和光学性能,在透过率为88.1%时,其方阻为12.3Ω/□,品质因子高达231。在5.0 mm的曲率半径下,对ZnSnO/AgNW双层透明电极进行了1 000次弯曲测试,其电阻仅增加了13%,表明ZnSnO/AgNW双层透明电极具有优异的柔性性能。此外,ZnSnO/AgNW双层透明电极经过20次胶带粘附测试和高温高湿测试后,方阻都基本保持不变,这说明ZnSnO/AgNW双层透明电极具有优异的粘附性以及抗氧化性。     

应用LaB6透明阴极的有机发光二极管器件

采用了类似于电子束蒸发工艺制备透明有机发光二极管(TOLED)的阴极。使用了一种新材料LaB6作为透明阴极,器件结构为ITO／TPD／Alq3／LaB6。LaB6薄膜的沉积是利用氧化物阴极的电子束轰击装在石墨坩埚的LaB6粉末。由于LaB6的功函数很低,器件具有良好的电子注入性能。器件在可见光光谱范围的透过率为70％左右,当驱动电压为7．2V,对应注入电流密度为4．8mA／cm^2,亮度可达100cd／m^2。     

采用碳纳米管导电薄膜作为OLED的阳极

采用碳纳米管(CNT)替代ITO作为OLED阳极可以 解决ITO薄膜存在的可弯曲性能差,可靠性低等缺 点,使得柔性显示成为可能。本文采用混合型CNT导电薄膜作为阳极,探讨了CNT薄膜的制备 工艺、掺 杂方式及表面修饰等因素对绿光OLED性能的影响。实验结果表明,P型掺杂对CNT薄 膜的导电性能影响 有限;而PEDOT修饰层可以很好的提高CNT导电薄膜的平整度;此外,采用“十字交叉 ”的阳极形状有助于降低 阳极拐角处毛刺。通过优化器件各参数,制备的PET/CNTs/PEDOT/NPB/ALq₃/LiF/Al绿光OL ED发光效率达 到了195 cd/m²,结果表明采用混合型CNT作为OLED阳极是可行的。     

Fully transparent flexible transistors built on metal oxide nanowires

Transparent electronics has attracted great research efforts in recent years due to its potential to make significant impact in many area, such as next generation displays, ultraviolet (UV) detectors, solar cells, charge-coupled devices (CCDs), and so on. Central to the realization of transparent electronics is the development of high performance fully transparent thin-film transistors (TFTs). One-dimensional (1-D) nanostructures have been the focus of current researches due to their unique physical properties and potential applications in nanoscale elec-tronics and optoelectronics. Among 1-D nanostructures, transparent metal oxide nanowires are one of the best candidates to make fully transparent TFTs. We provide in this paper the most recent development on the fabrication of fully transparent TFT using metal oxide nanowires as the device elements. First, the review article gives a general introduction about the development of transparent elec-tronics using different kinds of materials as the devices elements, including organic semiconductors, metal oxide thin films, and metal oxide nanowires. Second, the growth of metal oxide nanowires using vapor phase methods governed by two different growth mechanisms: vapor-solid mechanism and vapor-liquid-solid mechanism, respectively, are described. Third, the fabrication of transparent and flexible TFTs using different metal oxides nanowires is comprehensively described. In conclusion, the challenges and prospects for the future are discussed.     

Efficient flexible organic photovoltaics using silver nanowires and polymer based transparent electrodes

Planarization and filling voids between wires are key issues when using nanowire electrodes in flexible solar cells such as organic photovoltaics (OPV). For this purpose, we use poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) which leads to an electrically well connected silver nanowire (AgNW) network. Furthermore, the use of water based PEDOT: PSS leads to humidity assisted AgNW fusing, resulting in a maximum processing temperature of only 120 °C. OPV cells using this AgNW/PEDOT: PSS transparent electrodes exhibit power conversion efficiencies up to 7.15%. Moreover, OPV devices on PET substrates with an alumina encapsulation and barrier adhesive show excellent mechanical flexibility.     

基于PEN柔性衬底的顶发射微腔OLED性能研究

设计了结构为Ag/MoOx空穴注入层(HIL)/有机层/LiF/Al/Ag/Alq3的柔性有机电致发光器件(FOLED),研究通过改变HIL层的厚度改变腔长实现对微腔效应的调节,制备了性能优化的微腔FOLED。通过器件性能的对比,得到了可用Ag作为反射阳极的顶发射微腔FOLED全彩显示器件优化结构,即蓝、绿和红FOLED对应的优化HIL层厚度分别为100nm、120nm和160nm。     

All-solution-processed foldable transparent electrodes of Ag nanowire mesh and metal matrix films for flexible electronics

In this study, we developed foldable transparent electrodes composed of Ag nanowire (AgNW) networks welded by Ag nanoparticles (AgNPs) reduced from commercial Ag ink. All the processes used were solution-based. Using the Meyer rod method, uniform AgNW networks were roll-to-roll coated on large-area polymer substrates, and the spin-coated AgNPs firmly welded the AgNWs together at junctions and to substrates. The hybrid films consisting of AgNWs and the Ag film matrix exhibited higher electrical conductivity (5.0–7.3 × 10⁵ S/m) than and equivalent transparency (90–95%) to the AgNW networks. Furthermore, the hybrid films showed significantly better bending stability than AgNW networks. During cyclic bending tests to 10,000 cycles at 5 mm bending radius and even when almost folded with r_b of 1 mm, the resistivity changes were negligible because AgNWs were tightly held and adhered to the substrate by Ag films covering wires, thereby hindering fracturing of AgNWs under tension. Because the films were fabricated at a low temperature, there was no oxidation on the surfaces of the films. Hence, flexible organic light-emitting diodes (f-OLEDs) were successfully fabricated on polyethylene terephthalates (PET) coated with the hybrid films. The f-OLED in the bent state was comparable to that in the flat state, validating the potential applications of these transparent hybrid films as electrodes in various flexible electronics.     

Highly flexible organic light-emitting diodes based on ZnS/Ag/WO3 multilayer transparent electrodes

We report our study on highly flexible organic light-emitting diodes based on ZnS/Ag/WO₃ (ZAW) multilayer transparent electrodes in which high conductivity and ductility of Ag layers allow for efficient sheet conduction and flexibility while ZnS and WO₃ layers provide a means for enhancement in optical transmission and/or carrier-injection. Devices with ZAW anodes fabricated on planarized plastic substrates not only exhibit a performance and operational stability comparable to or better than those of ITO-based devices but also show a mechanical flexibility that is far superior to that of ITO-based devices. Experimental results show that a consistent performance can be obtained in ZAW-based devices upon repeated bending down to a radius of curvature of 5 mm, below which the flexibility of the devices is limited ultimately by the delamination occurring at cathode/organic interfaces rather than by the ZAW electrodes themselves.     

Ultrasmooth,highly conductive and transparent PEDOT:PSS/silver nanowire composite electrode for flexible organic light-emitting devices

The next generation of optoelectronic devices requires transparent conductive electrodes to be flexible, inexpensive and compatible with large scale manufacturing processes. We report an ultrasmooth, highly conductive and transparent composite electrode on a flexible photopolymer substrate by employing a template stripping method. A random silver nanowire (AgNW) network buried in poly(3,4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film constituted the composite electrode. Besides the effectively decreased surface roughness, its sheet resistance and transmittance are comparable to those of conventional PEDOT:PSS electrode. As a result, the efficiency of the OLEDs based on the composite electrode exhibited 25% enhancement compared to the OLEDs with conventional PEDOT:PSS electrode. Moreover, the performance of the flexible OLEDs remains stable after over one hundred bending cycles.     

Performance enhancement of III–V compound multijunction solar cell incorporating transparent electrode and surface treatment

To enhance the performance of tandem‐type III–V compound multijunction solar cells, the transparent indium‐tin‐oxide (ITO) film was used to replace conventional metal electrode for increasing the incident light area. For performing ohmic contact between the n‐AlInP window layer and the ITO film, a transition layer of Au/AuGeNi thin metals was used and investigated. Besides, to improve ohmic performance and to passivate the surface states, (NH₄)₂S_x surface treatment was used. The conversion efficiency of the (NH₄)₂S_x‐treated triple‐junction solar cells was increased more than 3.09%. Furthermore, an improved oblique SiO₂/SiO₂/ITO triple antireflection structure was designed to reduce the reflectivity of illuminating sunlight. The conversion efficiency of the (NH₄)₂S_x‐treated triple‐junction solar cell with improved antireflection structure could be improved more than 4.23%. Simple and effective approaches were designed to improve the performances of tandem‐type III–V triple‐junction solar cells. Copyright © 2010 John Wiley & Sons, Ltd.     

基于混合配体Znq(DBM)的单色和白色OLED

以8-羟基喹啉(q)和1,3-二苯基-1,3-丙二酮定向合成了有机小分子配合物Znq(DBM),将其作为发光层制备了单色有机电致发光器件(OLED)。在结构为ITO/m-MTDATA(5nm)/NPB(40nm)/Znq(DBM)(60nm)/LiF(0.5nm)/Al(100nm)的器件中,启亮电压为5V,最大亮度达到4 575cd/m2。同时又在器件中引入间隔层BCP,研究其不同厚度对OLED性能的影响。在结构为ITO/m-MTDATA(5nm)/NPB(40nm)/BCP(x nm)/Znq(DBM)(60nm)/LiF(0.5nm)/Al(100nm)的器件中,当BCP层厚为0nm时,发光颜色为黄绿色;当BCP层厚为1nm时,发光颜色为白色,色坐标为(0.29,0.33),最大亮度为2 231cd/m2;当BCP层厚为5nm时,发光颜色为蓝色。根据器件结构和性能,讨论了其内部机理。     

功率LED柔性封装结构的设计与热特性分析

根据功率LED的柔性封装要求,提出了基于贴片式(SMD)封装的功率型LED柔性封装结构。对各层结构进行了优化设计,采用有限元分析(FEA),模拟了柔性封装结构LED的热场分布。对比研究了柔性LED与传统封装结构LED的热特性,并对弯曲状态下柔性衬底材料对芯片的应力进行了分析。结果表明,采用金属Cu箔衬底的柔性封装结构,其散热特性较好;Cu/超薄玻璃复合衬底替代Cu箔衬底,可以减少弯曲的应力,减少幅度达到2.5倍,散热特性基本相同。SMD柔性封装的LED不仅具有较好的热稳定性,且具有柔性可挠曲特性,其应用潜力很大。