Single mode and multimodes lasing emission from MEH-PPV doped polystyrene thin films with surface ripples formed by vapour-induced phase separation

We report single mode and multimodes lasing emission from conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) doped polystyrene ( PS) thin films with surface ripples. Surface ripples were formed by water vapour-induced phase separation. A single mode lasing emission at 606 nm with a line-width of less than 0.4 nm was obtained. The laser threshold was as low as 3.5 mu J pulse(-1). The side mode suppression ratio was 5.76 dB. The periodic changes of the refraction index in the MEH-PPV : PS blending film due to the phase separation should be attributed to the lasing actions.

含电子传输基元发光聚合物的合成与表征

本论文是以提高聚合物电致发光器件发光效率和热稳定性为目的，从材料设计的角度出发，以具有电子传输性能和热稳定性1，3，4-噁二唑和1，2,4－三唑为构造单元，采用Wittig聚合反应合成了一系列含有1，3，4-噁二唑和1，2，4-三唑的发光聚合物，在载流子平衡和实现红、绿、蓝三基色发光方面取得了一些有益的结果，主要包括以下几点：1．合成了一系列含1，2，4-三唑单元和三芳胺单元的PPV型电致发光聚合物。研究了不同空穴传输单元对发光聚合物热性能和电化学性质的影响，结果表明，所有聚合物都具有比较高的玻璃化转变和热分解温度，其中由于联苯二胺中含有刚性联苯结构，使得含联苯二胺结构的聚合物较其它发光聚合物具有更高的玻璃化转变温度，并且由于联苯结构的空间位阻效应，减小了聚合物分子链间的相互作用，使得溶液态和薄膜态的光致发光峰位符合的很好。2.对所合成含1，2，4－三唑和三芳胺的发光聚合物进行了电致发光性能表征。研究了不同器件结构对发光亮度的影响。结果表明，所有的器件发光波长都在515－530nm之间。单层结构器件工TO/Polymer/Mg:Ag启动电压在6－9伏之间。发光亮度只有45 cd/m左右。双层结构工TO/Polymer/PBD/Mg:Ag发光亮度在100 cd/m~2左右，启动电压与单层器件几乎没有变化。这说明尽管在聚合物中引入了拉电子的三唑基团，但聚合物依然表现为空穴传输为主，这是由于三芳胺基团空穴迁移率比三唑的电子迁移率高；而且三芳胺单元和三唑基单元在聚合物中所占的比例也是三芳胺高的原因。3．我们首次合成了4－苯基－3，5－二（4一氯甲基苯基）－1，2，4－三唑化合物。中国科学院长春应用化学研究所博士论文经过反复实验最终确定了适合反应的合成路线，采用氯苯做溶剂，过氧化苯甲酞做引发剂，硫酞氯为反应试剂。合成的产物收率高，而且容易分离；采用三丁基磷盐为聚合单体，合成出高分子量的聚合物，并且聚合物基本上是以反式烯烃双键为主。4．以合成蓝色发光聚合物为目的。合成了二种1，2，4－三唑和联咔吟（咔哇）共聚的即V型蓝色发光聚合物和一种含有1，2，4－三唑的PPP型蓝色发光聚合物材料。研究结果表明，将1，2，4－三唑引入到电致发光聚合物中，有效地提高了聚合物的Tg，与相类似结构的蓝色发光聚合物相比，其热性能改善明显。聚合物的发光波长都在450pm左右，是比较纯正的蓝色发光。5．合成了有1,2,4一三唑(1,3，4一噁二唑）和不同MEH－PPV单元长度的发光聚合物，研究了不同的MEH－PPV单元长度对发光波长和玻璃化转变温度的影响。结果表明，当MEH－PPV单元长度增加时，发光波长和玻璃化转变温度都有向MEH－PPV接近的趋势。而且，由于聚合物中1，2，4－三唑中4位氮原子被苯环取代后提高了杂环的稳定性。在相同的MEH－PPV单元长度时，聚合物主链为1，2，4－三唑结构比聚合物主链是1，3，理一噁二唑的玻璃化转变温度高。6. 含1，2，4－三唑单元和三个单元长度MEH－PPV单元的发光聚合物的单层器件（ITO/Polymer/Mg：Ag）发光亮度为320cd/m~2。同MEH－PPV的单层EL器件相比，在相同的制备工艺条件下，聚合物的电致发光器佩件的发光亮度比MEH－PPV的单层电致发光器件高20％。7．研究表明1，3，4－噁二唑单元和1，2，4一三唑单元嵌入到MEH－PPV主链后，它们并不像脂肪柔性链那样完全中断了聚合物共扼性的延伸，1，3，4一噁二唑单元和1，2，4一三唑单元依然是聚合物的共扼成分，只是中国科学院长春应用化学研究所博士论文降低了聚合物的有效共辘程度；并且由于1，2，4一三唑单元空间结构特性使得聚合物有效共扼程度比1，3，4一噁二唑单元降低的更多。8.合成了含有1，3，4一噁二唑单元和不同发光中心的小分子发光材料，我们发现带烷氧基取代的发光小分子发光颜色向长波方向移动。而带有联苯结构的发光小分子发光颜色向短波长方向移动。9．发光小分子的紫外吸收峰与1，3，4－噁二唑单元的发光峰位存在着非常大的重叠，当用1，3，4－噁二唑的紫外最大吸收波长激发发光材料时，1，3，4－噁二唑所发出的光能够被共扼的发光小分子吸收，存在着能量转移的现象。

Low-threshold conjugated polymer distributed feedback lasers on InP substrate

We demonstrate a low threshold polymer solid state thin-film distributed feedback (DFB) laser on an InP substrate with the DFB structure. The used gain medium is conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) doped polystyrene (PS) and formed by drop-coating method. The second order Bragg scattering region on the InP substrate gave rise to strong feedback, thus a lasing emission at 638.9nm with a line width of 1.2nm is realized when pumped by a 532nm frequency-doubled Nd: YAG pulsed laser. The devices show a laser threshold as low as 7 nJ/pulse.

The effect of annealing treatment on performance of interdiffused organic photovoltaic devices

We fabricated the interdiffused organic photovoltaic devices, which composed of poly (2-methoxy-5-(2'-ethylhexyloxy)-1, 4-phenylenevinylene) (MEH-PPV) and buckminsterfullerene (C-60), by annealing treatment. After annealing, C60 diffused into the MEH-PPV layer, in consequence, MEH-PPV/C-60 interfacial area was increased and their interface became closer proximity. The results lead to reduce reverse-bias saturation current (J(s)), and increase the open-circuit voltage (V-OC) and the short-circuit current (J(SC)).

MDMO-PPV包裹PbS量子点和纳米棒材料及电池的制备方法

于AD批量导入至AEzhangdi

Synthesis of MDMO-PPV capped PbS quantum dots and their application to solar cells

Poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) capped PbS quantum dots about 3-6 nm in diameter were synthesized with a novel method. Unlike the synthesis of oleic acid capped PbS quantum dots, the reactions were carried out in solution at room temperature, with the presence of a capping ligand species, MDMO-PPV. The quantum dots were used to fabricate bulk heterojunction solar cells with an indium tin oxide (ITO)/polyethylenedioxythiophene/polystyrenesulphonate (PEDOT: PSS)/MDMO-PPV: PbS/Al structure. Current density-voltage characterization of the devices showed that after the addition of the MDMO-PPV capped PbS quantum dots to MDMO-PPV film, the performance was dramatically improved compared with pristine MDMO-PPV solar cells. (C) 2008 Elsevier Ltd. All rights reserved.

The synthesis of MDMO-PPV capped PbS nanorods and their application in solar cells

Poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) capped PbS nanorods about 100 nm in diameter and 400 nm in length were synthesized via a hydrothermal route in toluene and dimethylsulfoxide solution. By blending the PbS nanorods with the MDMO-PPV as the active layer, bulk heterojunction solar cells with an indium tin oxide (ITO)/polyethylenedioxythiophene/polystyrenesulphonate (PEDOT PSS)/MDMO-PPV PbS nanorods/Al structure were fabricated in a N-2 filled glove box, Current density-voltage characterization of the devices showed that the solar cells with PbS nanorods hybrid with MDMO-PPV as active layer were better in performance than the devices with the polymer only. (C) 2009 Elsevier B.V. All rights reserved.

Organic/inorganic hybrid solar cells based on SnS/SnO nanocrystals and MDMO-PPV

SnS/SnO heterojunction structured nanocrystals with zigzag rod-like connected morphology were prepared by using a simple two-step method. Bulk heterojunction solar cells were fabricated using the SnS/SnO nanocrystals blended with poly(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene) (MDMO-PPV) as the active layer. Compared with solar cells using SnS nanoparticles hybridized with MDMO-PPV as the active layer, the SnS/SnO devices showed better performance, with a power conversion efficiency higher by about one order in magnitude.

含空穴传输基团PPV的合成与性能研究

该论文以提高聚苯撑乙烯（PPV）类发光聚合物的空穴传输性能为主要目的,通过将具有较高空穴传输能力的芳胺类小分子基元引入发光聚合物分子链,设计并合成了一系列含芳胺基元的PPV聚合物.另外,还通过对分子结构进行设计和控制,获得了红绿蓝三基色发光.最后还利用在共轭分子主链上引入具有三维空间位阻的侧链基团,获得了高效率的绿色发光聚合物材料.

PPV齐聚物为基元的发光材料的合成与性能研究

PPV齐聚物（OPV）因为具有确定的发光结构，高的发光效率，和光电活性，被广泛的关注。本论文本围绕PPV齐聚物（OPV）展开研究。设计合成了有机／无机杂化型和热交联型高分子发光材料，解决了制作多层器件过程中，旋涂时下面的薄膜容易被溶解的问题。我们设计合成了一系列能量转移和传输平衡型高分子发光材料，并对材料进行了优化。1、利用末端带活性双酚的OPV与二甲基二苯胺基硅烷通过熔融缩聚反应，合成出以硅氧烷为嵌段单元的发光聚合物，并通过调节OPV单体上的取代基团实现聚合物的蓝光发射。2、在PPV的末端引入可交联的苯乙烯基元，在高温下实现PPV的交联，得到了耐溶剂的PPV薄膜，利用其耐溶剂的特点用简单的旋涂的方法制备了双层器件，与单层器件相比效率提高了约13倍，器件的最大亮度达7O0cd／m2。3、通过化学修饰在OPV的两端引入了活性的三乙氧基硅烷，利用三乙氧基硅的反应活性，将OPV通过Sol-Gd的方法固定到SiO2的基质中，OPV与基质之间的作用为化学键，这样有效的减少了OPV在基质中的聚集。同时我们制备了PMMA与OPV通过物理共混得到的Si-OPV/PMMA薄膜和不带活性基团的Me-OPV，通过Sol-Gel制备了Me-OPV／SiO2薄膜，结果表明，采用物理掺杂时，客体OPV在主体中存在明显的聚集；经过热处理后只有化学掺杂的薄膜形态和光谱仍然保持稳定。4、将两种不同的OPV发光单元通过稳定的芳醚键连接，得到了热稳性的聚合物，由于不同的发光单元之间的吸收和发射光谱存在重叠，我们观察到分子内的能量转移现象，通过能量转移提高了聚合物在薄膜和溶液下的量子效率和相应的电致发光效率。5、为了改善PPV类能量转移型发光分子的传输特性，通过Wittig反应在聚合物主链中引入了电子传输单元：噁二唑，三唑。为了优化材料我们调节了传输单元在主链中的含量，通过器件数据优化出电子传输基元在主链中的最佳含量。使得优化后的材料的器件效率比未引入传输单元的提高了10倍以上，最大亮度达到1300cd／m2。

High PL-efficiency ZnO nanocrystallites/PPV composite nanofibers

In this paper, we report for the first time on the synthesis of ZnO nanocrystallites in conjugated polymer (PPV) nanofibers by the coupling of the in situ/blend methods and electrospinning. These composite nanofibers were characterized by fluorescence microscopy, atomic force microscope (AFM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra, Fourier transform infrared (FT-IR) spectroscopy, and X-ray powder diffraction (XRD).

Synthesis, characterization, and electroluminescence of PPV copolymers containing electron and hole-transporting units

Three series of poly(phenylene vinylene) (PPV) derivatives containing hole-transporting triphenylamine derivatives [N-(4-octoxylphenyl)diphenylamine, N,N'-di(4-octyloxylphenyl)-N,N'-diphenyl-1,4-phenylenediamine, and N,N'-di(4-octoxylphenyl)-N,N'-diphenylbenzidine] (donor) and electron-transporting oxadiazole unit (2,5-diphenyl-1,3,4-oxadiazole) (acceptor) in the main chain were synthesized by improved Wittig copolymerization. The resulting donor-acceptor (D-A) polymers are readily soluble in common organic solvents, such as chloroform, dichloroethane, THF, and toluene.

Novel PPV-based light-emitting copolymers containing triazole moiety

Two new light-emitting PPV-based copolymers bearing electron-withdrawing triazole unit in the main chain have been synthesized by Wittig reaction between triazole diphosphonium salt and the corresponding dialdehyde monomers, respectively. Their optical and physical properties are characterized by UV-vis, photoluminescence (PL), TGA and DSC. The resulting copolymers are highly soluble in common organic solvents and have high Tg and Td values. They show blue-greenish fluorescence in solution (lambda(max) 502 and 508 nm) and green fluorescence in the solid state (lambda(max) 520 and 526 nm), respectively.