硅表面有机单分子膜的新表征方法──界面微分电容测量法

提出一种表征硅表面有机单分子膜的新方法界面微分电容测量法.通过对新制备的H-Si(111)表面和一系列烯烃分子修饰的硅表面/电解液界面的微分电容的研究,建立了硅表面有机膜结构和性质与界面电容之间的联系.实践证明这是一个简便、快速和有效的实验技术,为硅表面化学修饰与功能化研究提供了一个非常有力的工具.     

利用“湿化学”法在单晶硅表面接枝有机分子

在单晶硅表面嫁接有机分子是近年来硅表面化学领域的一个研究热点,引起了研究者的广泛重视。本文着重介绍了用“湿化学(wet chemistry)”方法在单晶硅表面嫁接有机分子的发展历程和最新研究进展,并探讨了在硅表面接枝有机分子后的一些研究结果及其未来的发展趋势。     

醇类在Si-H表面形成单分子膜的特性

以界面电容分析法为主并结合XPS、AFM技术研究了醇类分子在Si(111)-H表面上形成的有机单分子膜的特性。并探讨了嫁接反应中影响单分子膜特性的某些因素和单分子膜的稳定性及其对硅表面氧化的钝化作用。在所选择的反应条件下，不同链长醇分子修饰的硅表面上，嫁接分子所占体积分数约为80％，平带电位约为-1．00V(vs.SSE)。研究表明，这类膜稳定性和对硅表面氧化的钝化作用非常有限。     

芘分子共价修饰的硅纳米线制备及其发光性能表征

将功能分子共价链接于硅纳米线表面,是发展硅纳米线性能,获得新的硅纳米线器件材料的重要手段.但是对硅纳米线表面的修饰却存在产生不可控制的表面氧化层的缺点,因此有必要发展一种温和的新方法.本文通过羟基(—OH)与硅纳米线表面Si—H键反应生成Si—O—C键,从而在硅纳米线表面引入功能分子.并通过芘醇分子在硅纳米线表面的固定化,证明了这一方法能够温和地实现对硅纳米线表面的共价键修饰.     

硅表面嫁接有机单分子膜的研究近况

由于在微电子、化学 /生物化学传感器、纳米技术及太阳能等领域具有潜在的应用价值 ,通过 Si— C键在硅表面上直接嫁接有机单分子膜 ,已成为近几年新开展的研究热点 .对这一研究领域进行了概要综述     

金属有机框架材料在分离分析领域的研究进展

金属有机框架材料是由金属离子节点和有机配体通过配位键连接形成的具有序多孔骨架的材料, 因其具有比表面积大、 孔隙可调及表面性质可控等优点而备受关注. 通过对有机配体和金属离子进行选择及对金属有机框架材料进行后修饰处理, 可实现对金属有机框架材料表面性质的调控, 以提升其选择性吸附及特异性识别等性能, 进而拓展其在分离分析等领域的应用. 本文从金属有机框架材料的表面性质调控出发, 介绍了其表面性质与分离分析性能的关系, 总结了近年来该领域的代表性工作, 并展望了金属有机框架材料在分离分析领域的应用前景.     

硅芴类化合物的合成及应用研究进展

近年来,芴类结构9-位为硅桥联的硅芴类化合物以其独特的电子结构和光电性能受到研究者们越来越多的关注,这类化合物在有机发光二极管(OLED)、聚合物太阳能电池(PSC)、有机场效应管(OFET)等光电功能材料领域有广泛的应用前景。本文主要对硅芴类化合物的合成方法、结构修饰、性能及应用研究的最新进展进行了综述。     

硅纳米线阵列的制备及其光电应用

近年来,硅纳米线阵列在宽波段、宽入射角范围内优异的减反射性能及其在光电领域的巨大应用前景引起了相关研究者的广泛关注。本文综述了国内外硅纳米线阵列的制备及其在光电应用方面的最新研究进展。关于硅纳米线阵列的制备方法,主要从"自下而上"和"自上而下"两大类出发,分别阐述了模板辅助的化学气相沉积法、化学气相沉积结合Langmuir-Blodgett技术法和金属催化化学刻蚀法,其中重点介绍了目前使用最为广泛且操作简单的金属催化化学刻蚀法的步骤、机理及控制参数。关于硅纳米线阵列在光电领域的应用,主要阐述了硅纳米线阵列在光电探测器、常规太阳能电池、光电化学太阳能电池、光催化分解水制氢、光催化降解有机污染物方面的应用。最后,从硅纳米线阵列在实际应用中面临的提高光电转换效率和避免硅纳米线阵列腐蚀以提高器件的稳定性等问题出发,展望了硅纳米线阵列的表面修饰及修饰后的性能研究是未来硅纳米线阵列光电应用研究的主要方向之一。     

芳基硅磷光主体材料在有机电致发光器件中的应用

有机电致发光器件(organic light emitting diodes, OLEDs)在固态照明和平板显示等领域显现出巨大的商业应用前景,近年来受到人们的广泛关注。由于芳基硅基团的易修饰性和多功能性,可以通过连接结构不同的功能单元构建性能优异的主体材料,以此来实现高效的有机电致发光器件,因此近年来芳基硅基团在合成高性能电致发光主体材料方面获得了广泛的研究和关注。本文从材料的设计分类出发,综述了芳基硅主体材料的研究现状,对其分子结构特征、热力学性质、光物理性能、电化学性质及电致发光器件性能等做了详细的归纳总结,讨论了芳基硅主体材料在有机电致发光器件方面存在的不足,并展望了其应用前景和发展方向。     

通过硅烷偶联剂在硅和铟锡氧化物(ITO)表面嫁接寡聚芴分子

通过硅烷偶联剂γ-氨丙基三乙氧基硅烷(3-aminopropyl-triethoxysilane,APTES)的“分子桥梁”作用,采用两种不同的方法,把修饰后的寡聚芴分子键联到硅表面和铟锡氧化物(ITO)表面上。X射线光电子能谱(XPS)、原子力显微镜(AFM)和循环伏安(CV)方法等的表征证实了通过硅烷偶联剂在硅表面和ITO表面嫁接寡聚芴分子可行性。     

界面微分电容法单晶硅表面单分子膜质量的检测

有机嫁接;分析;界面微分电容法单晶硅表面单分子膜质量的检测     

Biomolecular stress-sensitive gauges: surface-mediated immobilization of mechanosensitive membrane protein

We report the observation of structural reorganizations associated with unique, stress-assisted gating of mechanosensitive (MscL) membrane protein on a silicon surface modified with alkyl-terminated monolayers. We observed that the shape of MscL membrane proteins changed dramatically depending upon the packing density of alkyl tails and the surface tension of the supporting organic layer. High-resolution atomic force microscopy confirmed a transition from an elongated, prolate shape of MscL molecules within a monolayer with low surface tension to a flattened, oblate shape with a wide central opening within a monolayer with high surface tension. These observations are consistent with the conformation reorganizations associated with the two-stage, "iris"-like expansion proposed for the gating of the MscL molecules.     

Exploiting poly(dimethylsiloxane)-modified tips to evaluate frictional behavior by friction force microscopy

With the aim of investigating the effect of the surface properties on the friction behavior of self-assembled monolayers, we have modified tipless atomic force microscopy (AFM) cantilevers with a poly(dimethylsiloxane) (PDMS) lens. The friction coefficient using the silicon tip is strongly influenced by the mechanical properties of the substrate monolayer because hard, sharp silicon tips penetrate the surface of organic monolayers. However, the friction coefficient obtained for the PDMS-modified AFM cantilever is mostly due to the surface properties of the monolayer functional end group, rather than the viscoelastic deformation of the monolayer. The use of the PDMS tip was demonstrated as a novel means to investigate the effect of surface properties on the frictional behavior of self-assembled monolayers with various functional groups with less mechanical deformation.     

硅表面有机单层膜 :微印章、微加工与微阵列

总结了作者的实验室在将有机物结合到硅表面方面的研究进展.发现并发展了将有机单层膜组装到硅、氧化硅和相关材料表面的新方法.这些方法简单、可重复，并可得到物理、化学性能良好的致密单层膜.这些单层膜在许多方面有令人鼓舞的应用，包括（a）应用于软印刷术，特别是微接触印章法; （b）用作硅的微加工（微机电系统，MEMS）的单层膜润滑剂; （c）用作DNA和蛋白质微阵列功能分子固定的基底.     

Alternative method for fabricating chemically functionalized AFM tips: silane modification of HF-treated Si3N4 probes

An alternative method for fabricating functionalized, atomic force microscopy (AFM) tips is presented. This technique is simple and requires only minimal preparation and tip modification to generate chemically sensitive probes that have a robust organic monolayer of flexible terminal chemistry attached to the surface. Specifically, commercially microfabricated Si3N4 AFM tips were modified with self-assembled monolayers (SAMs) of octadecyltrichlorosilane and (11-bromoundecyl)trichlorosilane after removing the native silicon oxide surface layer with concentrated hydrofluoric acid. The structure of these SAM films on solid silicon nitride surfaces was studied using contact angle goniometry and Fourier transform infrared spectroscopy. Pull-off force measurements on various bare (mica, graphite, and silicon) and SAM-functionalized substrates confirm that mechanically robust, long-chain organic silane SAMs can be formed on HF-treated Si3N4 tips without the presence of an intervening oxide layer. Adhesion experiments show that the integrity of the organic film on the chemically modified tips is maintained over repeated measurements and that the functionalized tips can be used for chemical sensing experiments since strong discrimination between different surface chemistries is possible.     

Electron beam-treated organic monolayers as a negative resist for Cu immersion plating on Si

In the present work, we investigate selective immersion plating of Cu on n-type Si(111) surfaces chemically modified with different organic monolayers and subsequently directly patterned by an electron-beam (e-beam). The organic molecules (1-undecylenic acid, 1-decene and 1-octadecene) were covalently attached to a hydrogen-terminated Si surface. The use of such monolayers as masks for electroless copper deposition by immersion plating on Si surfaces was investigated. Clearly, a masking effect can be observed, the efficiency of which depends on the type of molecule. Further, the effect of e-beam irradiation to improve the masking properties of the organic monolayers was studied. For this, the monolayers were locally irradiated using a scanning electron microscope (SEM) equipped with a lithographic tool. The results show that e-beam-modified organic monolayers can be used as a negative tone resist for copper electroless plating. The selectivity of the Cu deposition at e-beam-untreated regions strongly depends on the applied e-beam dose and on the nature of organic molecules. By optimizing the electroless deposition parameters, homogeneous deposition with complete selectivity can be achieved, leading to high lateral resolution of the Cu patterns.Dedicated to Zbigniew Galus on the occasion of his 70th birthday.     

Thiol-terminated monolayers on oxide-free Si: assembly of semiconductor-alkyl-S-metal junctions

Self-assembled monolayers formed by thermal hydrosilylation of a trifluoroacetyl-protected alkenylthiol on Si-H surfaces, followed by removal of the protecting groups, yield essentially oxide-free monolayers suitable for the formation of Si-C11H22-S-Hg and Si-C11H22-S-Au junctions in which the alkyl chains are chemically bound to the silicon surface (via Si-C bonds) and the metal electrode (via Hg-S or Au-S bonds). Two barriers to charge transport are present in the system: at low bias the current is temperature activated and hence limited by thermionic emission over the Schottky barrier in the silicon, whereas as at high bias transport is limited by tunneling through the organic monolayer. The thiol-terminated monolayer on oxide-free silicon provides a well-characterized system allowing a careful study of the importance of the interfacial bond to the metal electrode for current transport through saturated molecules.     

Silicon surface modification with a mixed silanes layer to immobilize proteins for biosensor with imaging ellipsometry

One kind of surface modification method on silicon wafer was presented in this paper. A mixed silanes layer was used to modify silicon surface and rendered the surface medium hydrophobic. The mixed silanes layer contained two kinds of compounds, aminopropyltriethoxysilane (APTES) and methyltriethoxysilane (MTES). A few of APTES molecules in the layer was used to immobilize covalently human immunoglobulin G (IgG) on the silicon surface. The human IgG molecules immobilized covalently on the modified surface could retain their structures well and bind more antibody molecules than that on silicon surface modified with only APTES. This kind of surface modification method effectively improved the sensitivity of the biosensor with imaging ellipsometry.     

Functionalization of acetylene-terminated monolayers on Si(100) surfaces: a click chemistry approach

In this article, we report the functionalization of alkyne-terminated alkyl monolayers on Si(100) using "click" chemistry, specifically, the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of azides with surface-bound alkynes. Covalently immobilized, structurally well-defined acetylene-terminated organic monolayers were prepared from a commercially available terminal diyne species using a one-step hydrosilylation procedure. Subsequent derivatization of the alkyne-terminated monolayers in aqueous environments with representative azide species via a selective, reliable, robust cycloaddition process afforded disubstituted surface-bound [1,2,3]-triazole species. Neither activation procedures nor protection/deprotection steps were required, as is the case with more established grafting approaches for silicon surfaces. Detailed characterization using X-ray photoelectron spectroscopy and X-ray reflectometry demonstrated that the surface acetylenes had reacted in moderate to high yield to give surfaces exposing alkyl chains, oligoether anti-fouling moieties, and functionalized aromatic structures. These results demonstrate that click immobilization offers a versatile, experimentally simple, chemically unambiguous modular approach to producing modified silicon surfaces with organic functionality for applications as diverse as biosensors and molecular electronics.