MEH-PPV多层结构器件的制备及其谱红移和窄化

研制了一种基于ITO／PEDOT／P—PPV／MEH—PPV／PFO／Ba／Al的多层结构器件，实现MEH—PPV发光峰的窄化和红移。该器件使MEH—PPV发射峰的半高宽（FWHM）由纯MEH—PPV单层的91nm减小到32nm，发光峰相对于MEH—PPV单层的582nm红移了20nm，相应的色坐标（CIE1931）由单层的（0．56，0．33）变为（0．62，0．38）。这种窄化和红移归为聚合物多层界面间的共混稀释效应。     

MEH—PPV夹层结构的430nm蓝色电致发光

本文首次报道了不同于MEH－PPV本征发光的蓝色发光。我们制备了以SiO2为加速层、MEH－PPV为发光层的有机／无机复合电致发光器件,用交流电压驱动时,除MEH－PPV的本征发光外,还得到了430nm的蓝色发光。我们认为430nm的蓝色发光是由被SiO2加速的电子直接碰撞MEH－PPV所致。     

倒置型PLED的电致发光特性研究

提出一种以聚合物MEH PPV为发光材料,结构为Al/MEH PPV/CuPC/ITO的倒置型发光器件(I PLED)。对既是空穴传输层又是轰击缓冲层的CuPC厚度以及MEH PPV的浓度对器件性能影响的分析发现,在实验条件下,最佳的CuPC厚度约为3.5nm,最佳的MEH PPV浓度约为3‰;采用小分子染料红莫稀(Rubrene)对聚合物发光材料MEH PPV掺杂发现,器件的亮度从未掺杂的40 4cd·m2提高到掺杂后的207.7cd/m2,其发光峰从未掺杂的624nm蓝移到掺杂后的592nm,但其I V特性并没有明显的变化。     

制备工艺对聚合物电致发光器件稳定性的影响

探讨了发光层厚度以及复合阴极材料对聚合物电致发光器件稳定性的影响,并通过对同一器件在不同初始亮度下的寿命进行测试比较,得到了该器件寿命的加速老化因子.然后,通过计算得知,结构为ITO/PEDOT:PSS/MEH.PPV/Ba/Al的聚合物电致发光器件在初始亮度为100 cd/m2情况下的寿命高达10 124 h,基本上...     

有机-无机复合薄膜电致发光器件中势垒对光电性能的影响

利用无机非晶SiO2与有机聚合物PPV复合制备了异质结器件,研究了不同层之间由于能级匹配而产生的势垒对整个器件的光电性能的影响。对于单层有机器件ITO/PPV/Al及双层有机无机复合器件ITO/PPV/SiO2/Al,空穴的注入取决于ITO/PPV界面的势垒,空穴是多数载流子,发光强度主要取决于电子的注入。单层器件电子的注入能力与PPV/Al界面的势垒有关;双层器件由于引进SiO2层,提高了电子的注入能力,其发光强度和发光效率较单层器件都有改善。对于3层有机-无机复合器件ITO/SiO2/PPV/SiO2/Al,在两个方向上电子注入的势垒不同,电子的注入能力有所差别,交流激发时,当Al电极为负(ITO为正)时,器件的最大瞬时发光强度是当ITO电极为负(Al为正)时最大瞬时发光强度的1.3倍。     

O—PPV中的残余溶剂对载流子传输特性的影响

在制作TIO／O－PPV/CuPc/Alq3/Al器件结构中,我们对可溶性PPV衍生物2－甲氧基－5－壬氧基－聚对苯乙炔（O－PPV）薄膜进行两种方法处理即：真空干燥和未干燥。结果发现,在加相同脉冲电压下（12V）,经真空干燥的器件的电致发光光谱主要来自O－PPV发光;未经干燥的器件,由于空穴和电子复合区域的变化Alq3发光比例有大幅度的提高,这表明,O－PPV中残余溶剂存在,薄膜中的空载流子迁移能力比干燥的薄膜有较大的提高,电子和空穴复合区域发生变化。     

电极材料对有机薄膜电致发光性能影响的研究

分别采用两种不同功函数的电子注入电极A1,Ca和三种不同功函数的空穴注入电极ITO,AZO(ZnO:A1),Au,制备出ITO/PPV/A1,Ca和ITO,AZO,Au/PPV/A1两个系列的电致发光器件.实验发现,采用不同的电极材料可使器件的J-V和B-V特性产生一定差异.我们还对其产生这种差异的原因进行了分析.     

退火处理对ITO表面特性及有机发光器件性能的影响

为了改善有机发光器件（OLEDs）的性能，在0～600℃不同温度下对ITO透明导电玻璃进行了退火处理。SEM观察到随退火温度的升高，ITO表面粗糙度增加；四探针电阻测试结果显示，在300℃以上温度退火后ITO表面电阻率有明显增加。用退火前后的ITO玻璃作为阳极制备了OLEDs，器件结构为ITO／TPD／Alq3／Al，比较器件的电流密度-电压特性曲线测试结果表明，ITO薄膜的热处理温度对OLEDs性能有显著的影响。     

热处理对单层聚合物电致发光器件性能的影响

本文分别对以MEH－PPV为发光层的橙色及以LPPP为发光层的兰色单层聚合物有机发光二极管（OLED）器件在不同的温度和时间条件下进行低真空热处理,分别确定了最佳热处理条件。经最佳条件热处理后器件的启亮电压降低1－2V,最大相对发光强度提高1个数量级,同一电压下相对能量效率提高了1．3－10．0倍。初步分析表明热处理方法提高器件光性能的原因在于改变了发光层与阴极接触界面的性质,增强了二者的结合能力,提高了电子注入水平。     

p型GaAs欧姆接触性能研究

为了研究半导体光电器件p-GaAs欧姆接触的特性,利用磁控溅射在p-GaAs上生长Ti厚度在10~50 nm范围、Pt厚度在30~60 nm范围的Ti/Pt/200 nm Au电极结构。利用传输线模型测量了具有不同的Ti、Pt厚度的Ti/Pt/200 nm Au电极结构接触电阻率,研究了退火参数对欧姆接触性能的影响,同时分析了过高温度导致电极金属从边缘向内部皱缩的机理。结果表明,Ti厚度为30 nm左右时接触电阻率最低,接触电阻率随着Pt厚度的增加而增加;欧姆接触质量对退火温度更敏感,退火温度达到510 ℃时电极金属从边缘向内部皱缩。采用40 nm Ti/40 nm Pt/200 nm Au作为半导体光电器件p-GaAs电极结构,合金条件为420 ℃,30 s可以形成更好的欧姆接触。     

Biodegradable Polyanhydrides as Encapsulation Layers for Transient Electronics

Bioresorbable electronic systems represent an emerging class of technology of interest due to their ability to dissolve, chemically degrade, disintegrate, and/or otherwise physically disappear harmlessly in biological environments, as the basis for temporary implants that avoid the need for secondary surgical extraction procedures. Polyanhydride‐based polymers can serve as hydrophobic encapsulation layers for such systems, as a subset of the broader field of transient electronics, where biodegradation eventually occurs by chain scission. Systematic experimental studies that involve immersion in phosphate‐buffered saline solution at various pH values and/or temperatures demonstrate that dissolution occurs through a surface erosion mechanism, with little swelling. The mechanical properties of this polymer are well suited for use in soft, flexible devices, where integration can occur through a mold‐based photopolymerization technique. Studies of the dependence of the polymer properties on monomer compositions and the rates of permeation on coating thicknesses reveal some of the underlying effects. Simple demonstrations illustrate the ability to sustain operation of underlying biodegradable electronic systems for durations between a few hours to a week during complete immersion in aqueous solutions that approximate physiological conditions. Systematic chemical, physical, and in vivo biological studies in animal models reveal no signs of toxicity or other adverse biological responses.     

锂离子电池用聚合物电解质的最新进展II.含液聚合物电解质

由于干态聚合物电解质目前还不能满足聚合物锂离子电池的应用要求,人们致力于开发含液体增塑剂的聚合物电解质,包括凝胶型和微孔型两类体系。本文综述了含液聚合物电解质的最新进展,重点论述了各种新体系和新方法。     

Are pyrolyzed polyimides conducting polymers?

We present the optical properties and the temperature dependence of the resistivity of the pyrolyzed polyimide Pyraliin® which is electrically conducting. Our results indicate that the pyrolyzed material can be described as consisting of carbonized islands in an insulating matrix.     

一种聚合物水化分子形态的环境扫描电镜观测方法

聚合物、交联聚合物、凝胶等含水样品水化分子形态呈链状、线团状及网状等结构,这些样品由于有大量水的存在,不能用普通扫描电镜直接观察,而干燥后的样品又容易导致聚合物分子缩聚。本文介绍利用环境扫描电镜,简单有效的观察聚合物、凝胶等含水样品的水化分子微观形态的实验方法。     

A Path Beyond Metal and Silicon:Polymer/Nanomaterial Composites for Stretchable Strain Sensors

Conventional strain sensors based on metals and semiconductors are rigid and cannot measure soft and stretchable objects. Thus, new strain sensors based on polymer/nanomaterial composites are attracting more interest. Although much effort has been dedicated to achieve high values of both sensitivity and stretchability with linearity, this work endeavors to search and establish guidelines for the development of stretchable strain sensors, by critically reviewing conventional sensors and examining recent progress. It starts from introducing key parameters for conventional strain sensors; these parameters are further discussed for their potential impact on new polymer/nanomaterial strain sensors. The work concludes that there are no general benchmarks for conventional strain sensors utilized in industry. From the findings, the authors suggest that stretchable strain sensors should be custom designed and developed to meet particular measurement requirements, in comparison with a generic aim of yielding a sensor with high degrees of stretchability, sensitivity, and linearity. Challenges are discussed, including reliability, calibration to be used as proper gauges, and soft data acquisition systems.     

σ-π共轭聚合物光折变特征研究

合成一种σ π共轭聚合物 poly(disilanylene 2 ,2′ bipyridine 5 ,5′ diyl)ruthenium (PDSBpy Ru) ,双光束耦合(2BC)、四波混频 (DFWM)及场致双折射实验等证明了该有机物的光导及光折变特性。由于铷化合物的金属与配位体间 (MLCT)电荷转移特性 ,使得该聚合物的光折变特性得以增强。实验测得双光束耦合增益系数为 30cm-1 ,四波混频实验测得光栅衍射率约为 1 0 %。     

A FLEXIBLE POLYMER FIBRE INFRASTRUCTURE FOR AN EVOLUTIONARY CUSTOMER PREMISES NETWORK

The developments in compressed digital video technology are paving the way for video-based services. Provision of such services requires a broadband communications network, which should extend into the customers' premises up to the terminals. This indicates a growing need for a customer premises network. This paper presents an infrastructure for an evolutionary and future-proof customer premises network. Such an infrastructure allows for early deployment and gradual upgrades associated with service demand. A key element in the concept is the use of the graded index polymer optical fibre (GIPOF) which combines an intrinsically high bandwidth with easy and therefore low-cost handling. There are two opposite approaches for the choice of network topology. In one approach, all applications are forced onto a single topology. In the other approach, the topology best suited for each application type is used. This paper considers the ‘best-suited topology’ approach and presents a network infrastructure that can support many topologies simultaneously as independent overlay networks. The proposed infrastructure consists of bundles of fibres, which can be interconnected and accessed by terminals in any required manner. © 1997 by John Wiley & Sons, Ltd.     

利用光聚合反应制作表面平整的聚合物光栅

提出利用紫外光聚合反应来制作聚合物光栅的方法．实验发现,光栅的表面起伏深度很小,约为12.4～0.7nm;折射率调制较大,达到0.010左右．这种方法在低阶分布反馈聚合物激光器的制作中具有很好的应用前景．     

聚合物光纤光谱特性研究

本文根据不同的精度要求,采用CCD光谱仪和高精度光谱仪测量了聚合物光纤的光谱损耗、吸收谱与发射谱,分析了这几种光谱特性,讨论了有源聚合物光纤中的拉曼谱对荧光谱的影响等现象。     

Structure Code for Advanced Polymer Electrolyte in Lithium-Ion Batteries

Over the past decade, lithium-ion batteries (LIBs) have been widely applied in consumer electronics and electric vehicles. Polymer electrolytes (PEs) play an essential role in LIBs and have attracted great interest for the development of next-generation rechargeable batteries with high energy density. Due to the several practical applications of LIBs and high demands for LIBs performance, many state-of-the-art PEs with different structures and functionalities have been developed to regulate the LIBs performance, especially their rate capability, cycling durability, and lifespan. In this review, the recent advances in high-performance LIBs prepared using well-defined PEs are summarized. The ion-transport mechanisms and preparation techniques of various well-defined PE classes compared to conventional PEs are also discussed. The aim is to elucidate the structure code for advanced PEs with optimized properties, including ionic conductivity, mechanical properties, processability, accessibility, etc. The existing challenges and future perspectives are also discussed, setting the basis for designing novel PEs for energy conversion applications.