非对称水溶性卟啉与钯(Ⅱ)显色反应的光度法研究

研究了非对称性５,１０,１５－三（４－甲基－３－磺基苯）－２０－［４－（５－氟尿嘧啶）－３－磺基苯］卟啉（ＭＦｕＳＰＰ）测钯的显色条件．在表面活性剂十二烷基磺酸钠存在下,ｐＨ４．５～６．０的弱酸性ＨＡｃ－ＮａＡｃ缓冲介质中,用抗坏血酸催化,Ｐｄ（Ⅱ）与ＭＦｕＳＰＰ形成１１配合物,最大吸收波长４１５ｎｍ,摩尔吸光系数ε＝１．８×１０５Ｌｍｏｌ－１ｃｍ－１,线性范围０～２．０μｇ／１０ｍＬ．该显色剂保持了对称性卟啉灵敏度高的优点,选择性和反应速度有明显改善．应用于混合样品和钯催化剂样品中钯的测定,结果满意     

含杂环的聚（间亚苯乙烯）发光材料的合成及其器件的发光性能

通过双锍盐前驱聚合法合成了含杂环的聚（２,５－二苯基－１,３,４－恶二唑）－３,３‘－乙烯（Ｍ－ＰＰＶ）,讨论了其较佳的合成路线,构造了ＩＴＯ／Ｍ－ＰＰＶ／Ａ１型电致发光器件,与未取代的ＰＰＶ所构器件ＩＴＯ／ＰＰＶ／Ａ１发黄绿乐相比,含杂环的聚（２,５－二苯基－１,３,４－恶二唑）３,３’－乙烯发光材料所构器件发蓝光。     

可溶性聚合物薄膜发光器件的电致发光

采用脱氯化氢反应合成出氯仿可溶性的ＭＥＨ－ＰＰＶ聚合物,用ＭＥＨ－ＰＰＶ作为发光材料制备了单层结构ＩＴＯ／ＭＥＨ－ＰＰＶ／Ａｌ和双层结构ＩＴＯ／ＭＥＨ－ＰＰＶ／Ａｌｑ３／Ａｌ电致发光器件,测量了器件的电致发光谱、Ｉ－Ｖ特性和Ｂ－Ｖ特性,利用能级理论分析了器件的发光特性了随器件结构的不同所具有的规律,实验表明,单层结构器件和双层结构器件的发光出现在ＭＥＨ－ＰＰＶ层,当加入Ａｌｑ３电子传输层／空穴阻挡     

液态金属离子源与聚焦离子束的研制进展

为了适应大规模集成器件制作工艺发展的需要，开展了液态金属离子源（ＬＭＩＳ）和聚 焦离子束（ＮＢ）的研究。研制成针型、同轴针型与毛细管型的镓与金ＬＭＩＳ，Ａｕ－Ｓｉ、Ａｕ－ Ｓｉ－Ｂｅ与 Ｐｄ－Ｎｉ－Ｓｉ－Ｂｅ－Ｂ三种共晶合金型 ＬＭＩＳ：研究了带有控制栅极的 ＬＭＩＳ的控 制性能；编制了计算聚焦离子枪所需的程序；制成三种型式的聚焦离子枪并获得０．１μｍ 直径的聚焦离子束；制成扫描离子显微镜（ＳＩＭ）；初步开展了刻蚀试验。     

功能覆盖膜对场发射阵列（FEA）电子发射性能的影响

为了寻找适合真空微电子器件的场发射阵列（ＦＥＡ）覆盖材料，我们采用了一系列功能材料作为覆盖膜，薄膜淀积采用离子束辅助淀积（ＩＢＡＤ）以及其它淀积技术。在１０＾－６Ｐａ下测量具有不同覆盖膜的硅ＦＥＡ二极管的Ｉ－Ｖ特性，测量结果表明除Ａｕ和Ｍｏ外，其它覆盖材料都对ＦＥＡ电子发射性能有改进，经ＴａＮ覆盖的ＦＥＡ发射电流最大。由Ｆ－Ｎ曲线估算出有效表面功函数和有效发射面积，从而说明以上所得的实验结果。     

Ti和AlN陶瓷的界面反应

采用电子束蒸发的方法在抛光的２００℃ＡｌＮ陶瓷衬底上淀积厚度为２００ｎｍ的Ｔｉ膜，并在高真空中退火．利用二次离子质谱（ＳＩＭＳ）、卢瑟福背散射谱（ＲＢＳ）、俄歇电子能谱（ＡＥＳ）和Ｘ射线衍射分析（ＸＲＤ）技术，研究了从２００～８５０℃温区内Ｔｉ与ＡｌＮ的固相界面反应，给出了界面组分分布随退火温度和时间的变化关系．在界面区发现了三元铝化物并观测到铝化物产生与发展过程．指出铝化物由Ｔｉ－Ａｌ二元和Ｔｉ－Ａｌ－Ｎ三元化合物组成．最后利用热力学理论对实验结果进行了解释     

AgNO3溶液中meso—四—（对磺基苯）卟啉的表面增强Raman光谱

本文研究了ＡｇＮＯ３溶液中ｍｅｓｏ－四－（对磺基苯）卟啉（Ｈ２ＴＳＰＰ）的表面增强Ｒａｍａｎ光谱（ＳＥＲＳ）。发现Ｈ２ＴＳＰＰ吸附于光还原的Ａｇ溶胶颗粒表面与银进行了络合反应，生成ｍｅｓｏ－四－（对磺基苯）卟啉银（Ⅱ）（Ａｇ（Ⅱ）ＴＳＰＰ）。对ＳＥＲＳ谱受波长及ＡｇＮＯ３溶液浓度的影响进行了讨论。结果显示光还原ＡｇＮＯ３溶液所形成的Ａｇ胶体，有希望成为一种制备简单而又具有实用价值的ＳＥＲＳ活性基底     

ABS/PA6/St-co-NPMI共混体系相界面特征研究

用小角Ｘ光散射法（ＳＡＸＳ）对ＡＢＳ树脂（丙烯腈Ａ－丁二烯Ｂ－苯乙烯Ｓ）／聚酰胺６树脂（ＰＡ６）／苯乙烯－马来酰胺共聚物（Ｓｔ－ｃｏ－ＮＰＭＩ）三元共混体系的界面结构进行了研究。由Ｄｅｂｙｅ散射理论中相关距离（ａｃ）和积分不变量（Ｑ）值随组成比变化显示,在ＡＢＳ／ＰＡ６／Ｓｔ－ｃｏ－ＮＰＭＩ（７０／３０／２,ｗｔ％）时,ａｃ＝５０．７４,Ｑ＝０．３９７２体系相容程度较高。这表明,Ｓｔ－ｃｏ－ＮＰ     

Ag－Cu混合型表面上的SERS效应

用还原法制备了一种Ａｇ－Ｃｕ混合型ＳＥＲＳ表面。通过电镜扫描和ｘ射线能谱分析，讨论了这种混合型表面形貌。在空气中检测了吸附在Ａｇ－Ｃｕ混合表面上的罗丹明６Ｇ的ＳＥＲＳ谱，简单分析了其光谱特征。实验结果表明，这种Ａｇ－Ｃｕ混合型表面可用于ＳＥＲＳ效应。     

非对称水溶性卟啉与钯（II）显色反应的光度法研究

研究了非对称性５，１０，１５－三（４－甲基－３－磺基苯）－２０－［４－（５－氟尿嘧啶）－３－磺基苯］卟啉（ＭＦｕＳＰＰ）测钯的显色条件，在表面活性剂十二烷基磺酸钠存在下，ｐＨ４．５￣６．０的弱酸性ＨＡｃ￣ＮａＡｃ缓冲介质中，用抗坏血酸催化，Ｐｄ（Ⅱ）与ＭＦｕＳＰＰ形成１：１配合物，最大吸收波长４１５ｎｍ，摩尔吸光系数ε＝１．８×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，线性范围０￣２．０μｇ／１０ｍｌ     

电化学沉积法制备Cu_2S薄膜及EPIR效应

以Na2S溶液为沉积液,在一定的温度、pH值、电压和时间下,采用电化学沉积的方法,在铜衬底上生长出一层质地均匀的蓝色Cu2S薄膜.通过XRD及SEM对样品的化学成分及表面与截面形貌进行表征,对Ag/Cu2S/Cu/Ag结构进行直流I-V及电脉冲诱导电阻转变(EPIR)效应测试.结果表明Ag/Cu2S/Cu/Ag结构的Ag/Cu2S结点处存在明显的EPIR效应,而且相对于单个Ag/Cu2S结点而言,Ag/Cu2S双结点具有更大的结点电阻且EPIR效应更明显.另外,Ag/Cu2S/Cu/Ag结构的EPIR效应还与测量的脉冲参数和测量温度有关.对于本样品而言,最佳测量温度为室温,脉冲宽度t0为0.000 1 s.     

电化学沉积法制备Cu2S薄膜及EPIR效应

以Na2S溶液为沉积液,在一定的温度、pH值、电压和时间下,采用电化学沉积的方法,在铜衬底上生长出一层质地均匀的蓝色Cu：s薄膜．通过XRD及SEM对样品的化学成分及表面与截面形貌进行表征,对G/Cu2S/Cu/Ag结构进行直流I-V及电脉冲诱导电阻转变（EPIR）效应测试．结果表明Ag/Cu2S/Cu/Ag结构的Ag/Cu2s结点处存在明显的EPIR效应,而且相对于单个Ag/cu2s结点而言,Ag/cu2S双结点具有更大的结点电阻且EPIR效应更明显．另外,Ag/Cu2S/Cu/Ag结构的EPIR效应还与测量的脉冲参数和测量温度有关．对于本样品而言,最佳测量温度为室温,脉冲宽度t0为0．00018．     

掺杂效应对氧化锡纳米晶微结构、形貌及其光学性能的影响

以二价SnCl2无机盐为原料，基于配合物前躯体方法制备了氧化锡及铜离子掺杂氧化锡纳米晶．根据DSC和TG分析结果在550℃对前驱体进行煅烧．运用FTIR、UV-VIS、XRD和TEM／HRTEM等测试手段对两纳米晶材料进行了分析表征．掺杂后掺杂相氧化物分散驻留在SnO2晶粒表面，阻止了SnO2晶粒表面的扩散，从而抑制其晶粒生长．此外，铜离子掺杂使得表面缺陷附近的自由电子能有效的定域化，从而使SnO2纳米晶体系的直接和间接带隙能均向高能方向移动．试验证明以无机盐代替金属醇盐为原料是切实可行的，且配合物前躯体法简单易操作，将有利于产业化．     

CsPbI3量子点在不同极性溶剂的光学特性

全无机钙钛矿CsPbI₃量子点具有发射谱线窄、荧光量子产率高和稳定性强等特点,在红光LEDs和新型太阳电池领域具有广阔的应用前景.本文通过热注入法在正己烷溶剂中合成了CsPbI₃ 量子点, 并对其结构和光学特性进行表征,结果表明,量子点主要的发光机制是量子限制区自由激子复合.通过改变溶剂的种类(正己烷、甲苯、乙酸乙酯、乙酸甲酯)对量子点的光学特性进行了调整,研究发现随着溶剂极性的增加,发光峰位从615 nm红移至660 nm,这是因为极性溶剂对量子点表面具有修饰作用,通过改变溶液极性实现CsPbI₃量子点发光峰位调节的条件为制备波长可调的光电器件提供了一定的实验参考.     

4H-SiC肖特基二极管载流子输运的温度效应

以Cree公司生产的碳化硅肖特基二极管为研究对象,对其进行I-V测试.通过对实验数据的理论模拟,研究了碳化硅肖特基二极管的载流子输运机理及温度效应.研究结果表明:温度升高,碳化硅肖特基二极管的肖特基势垒高度降低,漏电流急剧增加.正向导通时符合热电子发射机理,镜像力和隧穿效应共同作用使得反向偏压下的漏电流增加并能较好地和实验值相一致.     

A photovoltaic device structure based on internal electron emission

There has been an active search for cost-effective photovoltaic devices since the development of the first solar cells in the 1950s (refs 1-3). In conventional solid-state solar cells, electron-hole pairs are created by light absorption in a semiconductor, with charge separation and collection accomplished under the influence of electric fields within the semiconductor. Here we report a multilayer photovoltaic device structure in which photon absorption instead occurs in photoreceptors deposited on the surface of an ultrathin metal-semiconductor junction Schottky diode. Photoexcited electrons are transferred to the metal and travel ballistically to--and over--the Schottky barrier, so providing the photocurrent output. Low-energy (approximately 1 eV) electrons have surprisingly long ballistic path lengths in noble metals, allowing a large fraction of the electrons to be collected. Unlike conventional cells, the semiconductor in this device serves only for majority charge transport and separation. Devices fabricated using a fluorescein photoreceptor on an Au/TiO2/Ti multilayer structure had typical open-circuit photovoltages of 600-800 mV and short-circuit photocurrents of 10-18 micro A cm(-2) under 100 mW cm(-2) visible band illumination: the internal quantum efficiency (electrons measured per photon absorbed) was 10 per cent. This alternative approach to photovoltaic energy conversion might provide the basis for durable low-cost solar cells using a variety of materials.     

Microwave synthesis of Cu-doped ternary ZnCdS quantum dots with composition-controllable photoluminescence

Bright Cu-doped ternary ZnCdS quantum dots (ZnCdS:Cu QDs) with varied Cd concentrations were synthesized in aqueous solution by using a convenient microwave method.These ternary QDs could be directly dispersed in water solution.By regulating the Cd2+ concentration from 0 to 50% (mole fraction of the cations),the photoluminescence excitation (PLE) peak of such ZnCdS:Cu QDs could be continuously redshifted from 320 nm to 380 nm,while their photoluminescence (PL) peak was redshifted from 490 nm to 580 nm,exhibiting multicolor Cu-related emissions.Furthermore,the quantum yield of the ZnCdS:Cu QDs could reach as high as 12% by regulating the Cu doping concentration.These ZnCdS:Cu ternary QDs with kind surface conditions and good composition-controllable optical properties may have potential application in many areas such as sensing,bioimaging,and light-emitting diodes.     

n-type colloidal semiconductor nanocrystals

Colloidal semiconductor nanocrystals combine the physical and chemical properties of molecules with the optoelectronic properties of semiconductors. Their colour is highly controllable, a direct consequence of quantum confinement on the electronic states. Such nanocrystals are a form of 'artificial atoms' (ref. 4) that may find applications in optoelectronic systems such as light-emitting diodes and photovoltaic cells, or as components of future nanoelectronic devices. The ability to control the electron occupation (especially in n-type or p-type nanocrystals) is important for tailoring the electrical and optical properties, and should lead to a wider range of practical devices. But conventional doping by introducing impurity atoms has been unsuccessful so far: impurities tend to be expelled from the small crystalline cores (as observed for magnetic impurities), and thermal ionization of the impurities (which provides free carriers) is hindered by strong confinement. Here we report the fabrication of n-type nanocrystals using an electron transfer approach commonly employed in the field of conducting organic polymers. We find that semiconductor nanocrystals prepared as colloids can be made n-type, with electrons in quantum confined states.     

Ag纳米粒子增强CdS白光量子点器件的研制

在十八烯体系中合成Cd S量子点,用光诱导法制备银纳米粒子,并将两者复合,制备成4种复合样品,分析复合样品的荧光谱,在银纳米颗粒的表面等离子体共振峰分别对应于富含缺陷的硫化镉量子点的带边荧光峰和表面态荧光峰时,发生了带边荧光淬灭而表面态荧光增强的现象.结果表明,通过控制金属和量子点之间的距离,能够控制带边荧光辐射和缺陷带荧光辐射的比例,从而控制白光量子点的色温.采用395 nm紫光LED作为激发光源,将涂有荧光样品的玻片与激发光源组装成银纳米颗粒/量子点复合结构白光照明器件原型,银纳米粒子能够改变Cd S量子点样品发光颜色,荧光效应的增强程度随着量子点样品的厚度减小而加强.该研究为认识荧光物质和金属之间的相互作用提供了新途径,同时探讨了该器件在变色发光材料方向的应用前景.     

Molecular control over Au/GaAs diodes

The use of molecules to control electron transport is an interesting possibility, not least because of the anticipated role of molecules in future electronic devices. But physical implementations using discrete molecules are neither conceptually simple nor technically straightforward (difficulties arise in connecting the molecules to the macroscopic environment). But the use of molecules in electronic devices is not limited to single molecules, molecular wires or bulk material. Here we demonstrate that molecules can control the electrical characteristics of conventional metal-semiconductor junctions, apparently without the need for electrons to be transferred onto and through the molecules. We modify diodes by adsorbing small molecules onto single crystals of n-type GaAs semiconductor. Gold contacts were deposited onto the modified surface, using a 'soft' method to avoid damaging the molecules. By using a series of multifunctional molecules whose dipole is varied systematically, we produce diodes with an effective barrier height that is tuned by the molecule's dipole moment. These barrier heights correlate well with the change in work function of the GaAs surface after molecular modification. This behaviour is consistent with that of unmodified metal-semiconductor diodes, in which the barrier height can depend on the metal's work function.