Performances of ZnO-Based Dye Sensitized Solar Cells Fabricated by Hydrothermal Synthesis and Sol-Gel Technique

ZnO is introduced as an alternative to TiO2 in dye sensitized solar cells （DSSCs） due to its band gap similar to TiO2, higher electron mobility, and flexible procedures of preparations. Several samples of ZnO films are prepared with the hydrothermal synthesis method and the sol-gel technique, respectively. These ZnO films were assembled as photoanodes in DSSCs using N3 dye as the sensitizer. The ZnO-based cells prepared by the hydrothermal synthesis show typical current source characteristics, whose fill factor （FF） is 0.44 and photo-to-electric power conversion efficiency is 0.34%. On the other hand, all the samples prepared with the sol-gel technique show accompanied source characteristics with relatively higher power conversion efficiencies （1%） but a lower FF （0.26）. X-ray diffraction （XRD） and atomic force microscopy （AFM） measurements indicate that the sol-gel samples have small particles sizes. Therefore, sol-gel samples could adsorb more dye molecules to generate high conversion efficiencies. At the same time, more grain boundaries make it more possible for injected electrons to recombine with the oxidized electrolyte. Hydrothermal samples have bigger grains, so they show poor conversion efficiency and relatively high FF.     

纳米ZnS中的自激活发光

在水和乙醇体系中分别制备了尺寸在５ｎｍ左右的掺杂和未掺杂的ＺｎＳ纳米粒子,观察到了所谓自激活发光,在乙醇溶胸体系中这种发光比水溶胶体系不强两个数量级。对这种纂扩活发光的机理及其与纳米粒子形成过程的关系,表面活性剂的作用等进行了分析。     

固相萃取-超快速液相色谱-串联质谱法同时测定化妆品中9种抗过敏药物残留

建立了固相萃取-超快速液相色谱-串联质谱法(SPE-RRLC-MS/MS)同时测定化妆品中9种抗过敏药物残留(多西拉敏、美沙吡林、曲吡那敏、溴苯那敏、苯海拉明、赛克利嗪、二苯拉林、羟嗪和氯苯沙明)的方法。试样经三氯乙酸溶液超声提取、离心、Plexa PCX柱净化后,以甲醇-0.1%甲酸溶液(含5 mmol/L甲酸铵)为流动相,用RRLC进行分离。在电喷雾正离子模式下,以选择反应监测(SRM)方式采集数据进行定性与定量分析。9种药物在1.0～50.0!g/L范围内均呈良好的线性关系,相关系数均大于0.99;在2.0,5.0和20.0!g/kg3个浓度加标水平下的平均回收率为90.6%～103.5%;相对标准偏差(RSD,n=6)为2.5%～6.0%;检出限为0.3～0.6!g/kg,定量限为1.0～2.0!g/kg。     

悬空车轮形氮化镓发光二极管（英文）

减少器件的界面损耗从而提升其发光性能一直是发光二极管领域一个重要的研究热点。本文采用标准半导体工艺在硅衬底上制备了GaN基车轮形发光器件。采用各向同性湿法蚀刻工艺将器件悬空,比较并研究了悬空对器件的性能,包括光强、半高宽、波长漂移、3 dB带宽等的影响。由于减小了光损耗,在悬空结构中腔效应更加明显,器件的电致发光和通信性能得到了提升。本研究对电驱动光源的制备和可见光通信具有重要意义。     

高效液相色谱法测定火腿肠中的诱惑红

火腿肠经脱脂后,用乙醇-氨-水溶液提取色素,溶液经浓缩后,在酸性条件下用聚酰胺吸附,在碱性条件下解吸附,定容制成水溶液。以C18柱分离,用二极管阵列检测器检测,采用反相高效液相色谱法测定火腿肠中的食用合成色素诱惑红,回收率为85、8％～93．7％,测定结果的相对标准偏差为1．25％～2．39％,线性范围为1～100mg／L,检出限为0．5mg／kg。     

多孔"类碳糊电极"的羧基化及其对Escherichia ocli O157:H7的检测

以吡咯为前驱体,羧基化碳纳米管、石墨粉为填料和碳酸钙微球为模板直接诱导合成,制备出一种高灵敏的多孔"类碳糊电极"生物电化学传感器,讨论了羧基化碳纳米管含量、银染时间对检测结果的影响.结果表明,最佳羧基化碳纳米管含量为8%,最佳银染时间为12 min,银的阳极溶出峰电流与E. ocli O157:H7浓度在1.0×104～1.0×106 cells/mL范围内呈线性关系,其线性回归方程为:IP=-5.582+1 972logC,相关系数(R2)为0.9912,检出限为5.1×103cells/mL,实现了对E. ocli O157:H7快速、准确地检测.     

单根六方截面ZnO纳米针制备与发光特性

利用气相传输法,以高纯度氧化锌和碳粉为原料,通过高温碳热还原法制备出可分离单根针状ZnO纳米晶体。用XRD、SEM和PL等手段对其进行了表征。结果表明:样品系沿c轴方向生长、具有六方截面自组装ZnO纳米针(线)晶体。除具有一般线状ZnO纳米晶体相似的紫外光激励的PL谱外,在800nm飞秒激光脉冲激励下,从该样品可观测到上转换紫外受激辐射。     

有机吡啶盐的电致发光

有机盐是一种离子化合物,其分子间依靠比范德瓦尔斯力大得多的离子键结合,这有利于器件稳定性的提高。主要研究一种以新型有机吡啶盐ASPT(trans-4-[P-(N-ethyl-N-(hydroxylethyl)-amino)styryl]-N-methylpyridinium tetraphenyl-borate)作发光层的有机电致发光特性。实验发现有机盐ASPT是一种性能较好的红光发射材料。利用ASPT作发光层的单层电致发光器件,可获得稳定的红色电致发光。通过对外场界面势垒影响分析,我们讨论了这种单层器件的发光机理。为了探索ASPT中载流子传输与复合过程,并提高器件性能,设计了ASPT/Alq₃双层和TPD/ASPT/Alq₃三层结构的器件,进一步研究了它们的光电特性。实验结果表明,利用双层器件可获得亮度较高的红色发光。而在三层器件中,由于不同功能层的载流子传输特性的差别,激发复合区域受到驱动电压的显著影响,因此电致发光光谱随电压的变化而变化。通过对光谱结构、能级位置的分析,讨论了相关的发光机理。     

ZnO Nanorods Produced by the Method of Arc Discharge

ZnO nanorods are fabricated by arc discharge with ZnO powder as source materials. The sample is characterized by x-ray diffraction, Raman scattering spectra, scanning electron microscopy and high-resolution transmission electron microscopy. The ZnO nanorods exhibit single crystals with the hexagonal wurtzite structure. Many of them are tetrapod-like. The diameters range from several nanometres to about lOOnm, and the main diameters of the nanorods is around 20nm. The length-to-diameter ratio is more than 5, and the grown directions are along the [001] axis. Photoluminescence spectra show a narrow ultraviolet emission at around 389nm and a broad green emission at around 520 nm. The growth process can be interpreted by the vapour-solid mechanism.     

Photoluminescence of Electrospun Poly-Methyl-Methacrylate:Alq3 Composite Fibres

Tris（8-hydroxyquinoline） aluminium doped poly-methyl-methacrylate （PMMA：Alq3） composite nanofibres are fabricated by electrospinning. The morphology of fibres is characterized by scanning electron microscopy. The photoluminescence of a series of the nanofibres with various contents of Alq3 to PMMA is investigated. UVvisible absorption and the PL spectra analysis are employed to analyse the interaction between the polymer and the luminescent molecule.