Poly(3,4‐ethylenedioxythiophene) Derived from Poly(ionic liquid) for the Use as Hole‐Injecting Material in Organic Light‐Emitting Diodes

We report that poly(3,4‐ethylenedioxythiophene) derived from poly(ionic liquid) (PEDOT:PIL) constitutes a unique polymeric hole‐injecting material capable of improving device lifetime in organic light‐emitting diodes (OLEDs). Imidazolium‐based poly(ionic liquid)s were engineered to impart non‐acidic and non‐aqueous properties to PEDOT without compromising any other properties of PEDOT. A fluorescent OLED was fabricated using PEDOT:PIL as a hole‐injection layer and subjected to a performance evaluation test. In comparison with a control device using a conventional PEDOT‐based material, the device with PEDOT:PIL was found to achieve a significant improvement in terms of device lifetime. This improvement was attributed to a lower indium content in the PEDOT:PIL layer, which can be also interpreted as the effective protection characteristics of PEDOT:PIL for indium extraction from the electrodes.

     

LD抽运Cr,Tm,Ho∶YAG微片激光器单纵模运转特性的研究

研究了LD抽运的单纵模Cr,Tm,Ho∶YAG微片激光器,激光器厚度为1?mm,在用波长785?nm的LD进行端面抽运时,激光器阈值为1060?mW,单纵模激光最大输出功率为31?mW. 对激光器输出功率随温度变化特性进行了研究,验证了CTH∶YAG晶体的温度敏感性. 还研究了激光器的温度调谐特性,实验测得激光器的温度调谐系数为14?GHz/℃. 关键词： 激光光学 CTH∶YAG微片激光器 LD抽运 单纵模运转     

用于光纤拉曼放大器抽运源的单级光纤拉曼激光器

抽运光源是光纤拉曼放大器应用于密集波分复用系统的关键技术,设计了一种紧凑型的808nm激光二极管抽运的基于钒酸钇（Nd^3＋：YVO4）晶体1342nm固体激光器模块,提出利用上述1342nm固体激光器抽运基于光纤光栅的单级全光纤型拉曼谐振器获得1．4μm激光输出的光纤拉曼激光器,分析了固体激光器的阈值特性、性能优化方法和单级光纤拉曼谐振器的设计方法。上述1342nm固体激光器模块在抽运功率2W时获得了最大655mW的激光输出功率和42．6％的斜率效率,单级拉曼谐振器的1342nm到1．4μm光功率转换斜率效率达75％,在1425nm、1438nm、1455nm和1490nm处的输出功率达到300mW以上。最后给出基于1．4μm光纤拉曼激光器抽运的宽带平坦放大的光纤拉曼放大器的结构参量和性能测试结果。     

多色脉冲激光光源研究

采用钛宝石锁模飞秒激光器作为泵浦光源,利用1.8 μm纤芯的保偏光子晶体光纤的高非线性特性产生超连续谱,通过调节泵浦光源和光子晶体光纤之间的耦合,在可见光区,获得了中心波长分别在431 nm, 497 nm, 520 nm, 575 nm的mW量级的不同颜色的激光输出,并且测量输出的脉冲序列重复频率与泵浦光的一致,具有良好的稳定性.     

Tb3+∶YAG单晶荧光层中掺杂Ga3+的荧光敏化作用

采用液相外延工艺成功制备了Tb3 + ∶YAGG单晶荧光层 ,研究了Tb3 + 激活YAG主晶格外延层中Ga3 + 掺杂的荧光敏化效应 ,可以看到在Tb3 + 荧光得到显著增强的同时 ,外延荧光层发光的饱和特性也有所改善。实验中观察到了Ga3 + 掺杂后基质晶体吸收边缘向长波方向展宽 ,并与Tb3 + 的7F6 9E、7E典型吸收峰发生交叠的现象 ,用基质与Tb3 + 之间的声子耦合解释了上述Tb3 + ∶YAGG外延层中所存在的能量传递、荧光敏化现象。基质与掺杂激活中心间能量传递机制的建立将会为基于YAG主晶格的高效荧光材料研究提供一个新的思路。     

双频激光技术研究新进展及发展趋势

双频激光器在干涉测量和光学传感等技术领域扮演极其重要的角色。综述了近年来双频激光技术研究的新进展(包括双折射双频He Ne激光器、双折射双频Nd:YAG激光器和双纵模半导体激光器),简要介绍了各种双频激光器的工作原理,分析了这些双频激光器在频差大小、频差稳定性和频差调谐特性等方面的优缺点,指出了今后双频激光技术研究的发展趋势。     

Electrochemical synthesis of PEDOT derivatives bearing imidazolium‐ionic liquid moieties

Novel poly(3,4‐ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium‐ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4‐ethylenedioxythiophene (EDOT) unit and an imidazolium‐ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF₃SO₂)₂N^?), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, ¹H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF₃SO₂)₂N^? > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010–3021, 2009     

Silver Nanograins Incorporated PEDOT Modified Electrode for Electrocatalytic Sensing of Hydrogen Peroxide

A silver nanograins (Ag_NGs) incorporated poly[3,4‐ethylenedioxythiophene] (PEDOT) modified electrode was prepared by a simple electrochemical method without using any stabilizer or reducing agent. The surface morphology and thickness of the resulting modified electrode was characterized by using AFM. It was found that the size of the silver particles in the PEDOT modified electrode was smaller than that in the bare electrode. AFM studies also revealed that Ag_NGs were uniformly distributed in the PEDOT modified electrode and the thickness of the film was found to be 35 nm. The Ag_NGs incorporated PEDOT modified electrode exhibited good electrocatalytic activity towards the reduction of hydrogen peroxide without an enzyme or mediator immobilized in the electrode. It has shown good amperometric response to hydrogen peroxide (H₂O₂) with a detection limit of 7 μM and a response time of 5 s.     

Electrogenerated chemiluminescence biosensor based on Ru(bpy)3(2+) and dehydrogenase immobilized in sol-gel/chitosan/poly(sodium 4-styrene sulfonate) composite material

A new electrogenerated chemiluminescence biosensor was fabricated by immobilizing ECL reagent Ru(bpy)₃²⁺ and alcohol dehydrogenase in sol-gel/chitosan/poly(sodium 4-styrene sulfonate) (PSS) organically modified composite material. The component PSS was used to immobilize ECL reagent Ru(bpy)₃²⁺ by ion-exchange, while the addition of chitosan was to prevent the cracking of conventional sol-gel-derived glasses and provide biocompatible microenvironment for alcohol dehydrogenase. Such biosensor combined enzymatic selectivity with the sensitivity of ECL detection for quantification of enzyme substrate and it was much simpler than previous double-layer design. The detection limit was 9.3 × 10⁻⁶ M for alcohol (S/N = 3) with a linear range from 2.79 × 10⁻⁵ to 5.78 × 10⁻² M. With ECL detection, the biosensor exhibited wide linear range, high sensitivity and good stability.     

Tb3+掺杂CePO4花状团簇的控制合成及发光性能

在无模板条件下,通过调节Tb3+的浓度水热法控制合成了CePO₄∶Tb花状团簇。花状团簇由直径为80～90 nm、长度约为1 μm的纳米线组成。利用X射线衍射(XRD)、场发射扫描电镜(FE-SEM)和荧光光谱分析了产物的相结构、晶粒尺寸、形貌及发光性能。当Ce3+/Tb3+摩尔比为0.850∶0.150时,Tb3+在过量的磷酸体系中诱导纳米线组装生长成花状团簇。发现反应物Ce3+/Tb3+摩尔比和磷酸浓度影响产物形貌的控制合成。并推测了花状团簇的生长机制。产物CePO₄∶Tb的荧光性质测试表明,当Ce3+/Tb3+摩尔比为0.850∶0.150时,所合成的花状团簇的发射强度达到最大值,Tb3+的掺入量继续增加其发光强度迅速降低。