衬底温度对HfOxNy薄膜光学性质的影响

采用射频反应磁控溅射法制备了HfOxNy栅介质薄膜,并研究了HfOxNy栅介质薄膜的光学特性随淀积温度的变化而发生变化的规律．椭偏仪模拟结果显示HfOxNy薄膜的折射率和消光系数都是随衬底温度的升高而增加,根据消光系数和吸收系数还得到了HfOxNy薄膜的光学带隙值,随着衬底温度的升高,带隙减小,这主要是由于N含量的增加所致．     

衬底温度对用RF-PECVD法制备的非晶硅薄膜光学性能影响

采用射频等离子增强化学气相沉积(RF-PECVD)工艺制备非晶硅(a-Si:H)薄膜, KBr衬底在175-275 ℃范围内变化, 用傅立叶红外光谱仪(FTIR)测试KBr衬底上的薄膜红外光谱峰随衬底温度的变化情况, 结合红外光谱峰的理论分析确定薄膜中氢含量随衬底温度的变化规律. 光谱式椭圆偏振仪中用Forouhi Bloomer (FB)模型拟合得到薄膜的折射率(n), 消光系数(k), 膜厚及光学禁带宽度(Eg), 并用扫描电镜(SEM)断面分析对椭偏仪测试结果的准确性进行验证. 根据Tauc公式推出薄膜的Eg和截止波长, 并和FB模型得到的结果进行了比较, Eg(FB)和Eg(Tauc)的差值在0.015 eV内.     

基于薄膜光学理论的光纤表面等离子共振传感器研究

为完善光纤表面等离子共振传感器设计方法,在MATLAB环境下,基于薄膜光学理论,以金属薄膜复介电常数的虚部、实部、膜层厚度、光纤纤芯折射率、环境介质折射率为中间参量建立数值计算模型,研究讨论了各自对光纤表面等离子体共振传感头反射谱的影响。利用实验对数值计算结果进行验证。给定传感头的光纤与薄膜结构参数,在较大的环境介质折射率折变化范围内,可能观测到多个表面等离子共振点,环境介质折射率不同的有效测量范围,对纤芯折射率、薄膜厚度有着不同的临界取值要求。这可为波长调制型光纤SPR传感器测量方案优化,提供相应理论指导。     

可录型光盘(CD-R)中染料膜层的光谱性质和光学特性

本文利用光在多层膜介质中的传播模型,计算了可录型光盘（ＣＤ Ｒ）中染料媒体的光学特性．表明在适合于ＣＤ Ｒ光盘记录的７８０ｎｍ波长处,由于多层膜中光的干涉作用,样品反射率随薄膜的厚度变化发生振荡．振荡的幅度和周期依赖于染料薄膜的复数折射率（ｎ＋ｉｋ）．当记录介质层的复数折射率在２．１＋ｉ０．０２至２．８＋ｉ０．１２之间时,能够满足ＣＤ Ｒ光盘对染料介质的要求．通过对三种菁染料薄膜的光谱性质分析及光学参数的模拟计算,证实了该方法用于染料薄膜光学特性研究的合理性．并为选择适合于光记录的染料薄膜的厚度范围提供了简便的方法     

聚苯乙烯重氮盐的单组分逐层自组装研究

利用聚苯乙烯重氮盐(PS-DAS),通过单组分逐层自组装,得到了厚度可控的超薄膜.采用紫外可见光谱,椭偏仪,原子力显微镜等对自组装膜的增长和表面形貌进行了表征,并对其交联前后的性质进行了研究.结果表明,利用逐层自组装步骤可以制备膜厚均匀增长的PS-DAS膜.组装过程中的吹干步骤对自组装膜的增长起重要作用.在加热条件下,超薄膜可以发生交联反应,得到疏水的表面。     

衬底温度对ZnO薄膜生长过程和微结构的影响

从原子尺度上去研究薄膜生长过程中温度对薄膜取向性、缺陷结构以及薄膜完整性的影响和作用规律, 对于解释薄膜生长的物理本质、控制生长条件、提高薄膜制备的质量具有重要意义. 本文应用基于反应力场的分子动力学方法研究了ZnO薄膜(000l)表面作为衬底的薄膜沉积生长过程, 初步讨论了衬底温度(200、500和800 K)变化对沉积较薄ZnO膜质量的影响, 部分结果与实验观察相符. 结果表明, 衬底温度在500 K左右时, 沉积原子结构径向分布函数曲线特征峰尖锐、明显, 有序度较高, 注入和溅射对薄膜完整性影响较小, 沉积形成的薄膜结构稳定而又致密. 在预置衬底表面平坦的情况下薄膜呈现一种链岛状的生长模式, 每原子层均具有两种生长取向, 导致其生长前锋交汇处形成了一种新的有序缺陷.     

自组装超薄膜修饰Ta2O5介质膜及其特性研究

采用静电自组装方法在五氧化二钽(Ta2O5)介质氧化膜上制备了聚二烯丙基二甲基氯化铵(PDDA)/聚苯乙烯磺酸钠(PSS)和聚二烯丙基二甲基氯化铵/聚-3,4-乙烯二氧噻吩-聚苯乙烯磺酸钠(PEDOT-PSS)超薄膜.研究了两种自组装超薄膜在Ta2O5介质氧化薄膜上的组装特性.结果表明两种自组装膜能够稳定地组装于Ta2O5介质膜表面,并有效降低薄膜的表面粗糙度.进一步研究了两种自组装超薄膜修饰的Ta2O5电容结构的电性能.结果表明静电自组装膜对Ta2O5介质膜表面进行修饰后,有效地隔离了介质氧化膜中的缺陷,降低了电容的漏电流并提高耐电压能力;研究还发现不同厚度的超薄膜对Ta2O5电容结构的耐压特性有不同程度的影响,较厚的薄膜可以更好地提高电容的耐压能力并降低漏电流,但会增加电容的等效串联电阻(ESR).另外,在相同薄膜层数的情况下,聚合物电解质PEDOT-PSS良好的导电性能降低了复合超薄膜的电阻,使得PDDA/PEDOT-PSS修饰的电容结构ESR值较低.     

三甲基氯硅烷对纳米多孔二氧化硅薄膜的修饰

以正硅酸乙酯为先驱体,采用溶胶-凝胶法,结合旋转涂胶、超临界干燥工艺在硅片上制备了纳米多孔SiO2薄膜.用三甲基氯硅烷(TMCS)对该SiO2薄膜进行了表面修饰,采用FTIR、TG-DTA、AFM和椭偏仪等方法研究了TMCS修饰前后薄膜的结构、形貌、厚度与介电常数等性能.超临界干燥后的SiO2薄膜含有Si－O－Si与Si－OR结构,呈疏水性.在空气中250 ℃以上热处理后SiO2薄膜因含有Si－OH而呈吸水性. TMCS修饰后的SiO2薄膜在温度不高于450 ℃时可保持其疏水性和多孔结构. SiO2薄膜经TMCS修饰后基本粒子和孔隙尺寸增大,孔隙率提高,介电常数可降低至2.5以下.     

微电极结构Ag/ZnO/NiO三层复合膜的制备及光催化性能的研究

通过溶胶-凝胶结合光还原沉积法在普通玻璃片上制备了Ag-ZnO-NiO系复合薄膜。使用SEM,PL,XRD,UV-Vis等手段对薄膜的表面形貌,物相组成及光学性质作了考察和研究。XRD和UV-Vis分析表明复合薄膜中包含NiO和ZnO的双层异质结构;FESEM结果表明Ag和ZnO分别在其各自的衬底上生长但没有形成完全覆盖,PL光谱表明三层膜的发光强度小于双层膜和单层膜。使用甲基橙为模型底物测试了薄膜在紫外线下的光催化氧化能力,结果表明,三层复合薄膜Ag/ZnO/NiO的活性相比氧化锌单层薄膜和双层薄膜有不同程度的提高。这是由于上层薄膜不能完全包裹下层膜,导致在表面形成了许多微电极结构,这些微电极结构能够使光生电子空穴对得到有效分离。     

聚氨酯载体的逐层自组装亲水改性研究

利用自组装技术在聚氨酯载体表面制备超支化重氮盐(HB-DAS)/聚苯乙烯磺酸钠(PSS)多层膜,通过红外和椭偏仪表征膜的组装过程,利用接触角研究改性后载体的亲水性和稳定性,并对载体改性前后的生物学性能进行评价。结果表明,HB-DAS和PSS可在聚氨酯表面形成均匀的薄膜。改性后聚氨酯表面具有良好的亲水性,接触角随组装层数的增加而降低,改性载体具有良好的耐酸碱性。改性后载体对微生物的吸附性能明显优于改性前,明显缩短生化系统的启动周期。     

Unraveling the spatial distribution of immunoglobulins, enzymes, and polyelectrolytes within layer-by-layer self-assembled multilayers. Ellipsometric studies

The ellipsometric characterization of a layer-by-layer electrostatically self-assembled multilayer of polyphenol oxidase and alkaline phosphatase with the polycation poly(dimethyldiallylammonium chloride) built on an immunologic layer formed by immunoglobulin G (IgG) and glucose oxidase-conjugated anti-IgG (IgG-GOD) on glassy carbon is reported. The step-by-step evolution of the psi-Delta ellipsometric angles was followed during film growth. Two optical models, named the three-layer film model and reorganization film model, were employed and found suitable for ellipsometric data interpretation. A comparative analysis of film optical properties, film thickness, and ellipsometric mass assessed from both models is also presented.     

Ni（OH）2与NiOOH间相互转化的波长扫描椭圆偏振光谱分析研究

用波长扫描现场椭圆偏振光谱方法研究了镍电极上的电化学反应。ｖｏｐ光波以及拟合椭圆偏振实验数据证明，镍电极表面膜可用单层有效介质膜模型描述；椭圆偏振光谱法可用于表于表面分析。     

聚对苯二甲酸乙二酯光学特性的椭圆偏振光谱研究

概要介绍椭圆偏振光谱 (SE)的原理与特点 ,并用椭偏光谱测定了一组结晶度不同的无取向PET薄膜的光学常数谱 ,研究半结晶性高聚物PET不同结晶形态对其光学性能的影响 ,发现随结晶度的增加 ,其光学常数显著增大 ,并趋于晶态的光学常数 .光学性质的改变可能与微晶的尺寸有关     

Ellipsometric examination of electrically conductive films of poly(2,5-thiophenediyl)

A polymer film formed by anodic oxidation of thiophene in acetonitrile on platinum at 2.08 V was examined by ellipsometry. The refraction index and absorption index were determined as a function of the wavelengths. The optical thickness was determined and compared with the electrical charge. Stoichiometric film growth by a two-electron reaction followed this comparison. The film properties studied were almost independent of the potential between −0.1 and +2.08 V. The time dependence of the ellipsometric parameter showed the film growth to be approximately linear with square root of time, typical for a diffusion controlled reaction.     

Plasma Polymerization on Metals

An ellipsometric technique is described for accurately measuring the film thickness of plasma-polymerized polymers on metallic substrates. The index of refraction n and absorption index Kof the plasma polymer film can also be studied by ellipsometry. Films of plasma polystyrene and polyepichlorohydrin were deposited on evaporated aluminum substrates and their thickness and optical constants determined. Plasma polystyrene films from 20 to 1600 Å thick have optical constants n = 1.63 and K =0 independent of film thickness. Plasma polyepichlorohydrin films over the same range of thickness give n ? 1.70 and K? 0.01. By utilizing the ellipsometric method the effect of plasma polymer film thickness on surface energy properties was determined. Advancing contact angle measurements and surface energy analysis detail the polar γSV^P dispersion γSV^Pcontributions to the solid-vapor surface tension γSV = γSV^d + γSV^P Polystyrene and polyepichlorohydrin films on etched aluminum. For thin plasma polystyrene films (600 Å), anomalies in the calculated surface energy are discussed and related to possible surface nonuniformity caused by film growth. Thicker films of plasma polystyrene are shown to have normal surface energy properties as does plasma poly-epichlorohydrin over the entire range of film thickness measured. The adhesive and cohesive properties of plasma polystyrene and polyepichlorohydrin films are discussed as estimated from a lap-shear bond strength study. Etched aluminum coated with various thicknesses of these two polymers and bonded with an epoxy-phenolic adhesive shows a decreasing shear strength with increasing plasma film thickness but begins to level off at ～1600 psi for films >1600 Å thick.     

Cleaning of Silicon and Steel Surfaces Using Dielectric Barrier Discharges

The plasma-activated removal of oil from contaminated silicon substrates and galvanized steel sheets has been performed using dielectric barrier discharges (DBD) at atmospheric pressure. Removal rates were determined by ellipsometric measurement of the oil film thickness, using polished silicon as substrates. With galvanized steel sheets, qualitative and quantitative investigations were done using fluorescence microscopic characterization of theplasma-treated surfaces. Both the ellipsometric and the fluorescence microscopic measurements yield the dependence of the removal rate on treatment parameterssuch as plasma–gas composition and gas flow. The film thickness measurements were calibrated using quantitative IR spectroscopic measurements. It could be shown that the removal rate increases with increasing oxygen content in the process gas, static removal rates of 0.6 nm/s and 7 nm/s being obtainedin pure nitrogen and in pure oxygen, respectively. Fluorescence microscopic investigations showed that oil can be removed even from grooves in the galvanized steel sheets.     

Polyaniline Formed in Alkaline Solution─A New Luminous Material

IntroductionPolyaniline (PAN) prepared in acidic aqueous media has received a great deal of interestas one of the conductive polymers due to its straightforward methods of preparation andthe stability of its conductive form in airl'2. Its applications as energy storage media3 andas electrochromic device4 have been discussed. But there are few reports about theelectropolymerization of aniline in alkaline solutions.In this paper, we report the results of an ellipsometric study of theelectropol…     

Formation of Ultrathin Films at the Solid-Liquid Interface Studied by In Situ Ellipsometry

Ellipsometric investigations of self-assembled monolayers (SAMs) of alkylsiloxanes on native silicon substrates and of organothiols on gold substrates were performed under in situ conditions with the substrate in direct contact with the adsorbate solution. Specially designed liquid cells matched for different incidence angles were used to carry out measurements in a range of organic solvents with different refractive indices as the ambient medium. The observed shifts in the ellipsometric phase angles Delta upon monolayer formation were found to depend very sensitively on the incidence angle and the refractive indices of the adsorbate film and the ambient solvent, from which a rather simple method for determining the refractive index of the adsorbate film, based on a variation of the ambient refractive index, was derived. Time-resolved in situ measurements of SAM formation in different solvents and onto different substrates yielded accurate kinetic information on the monolayer growth process and revealed hitherto unknown strong solvent effects on the growth rate. Copyright 1999 Academic Press.     

The effect of water or salt solution on thin hydrophobic films

Hydrophobic films of polystyrene synthesized in bulk (PS) and by emulsion polymerization in the presence of the cationic surfactant cetyltrimethylammonium bromide (PS-CTAB) or the anionic surfactant sodium dodecyl sulfate (PS-SDS) were characterized by means of ellipsometry, contact angle measurements, and atomic force microscopy. Thin (approximately 65 nm) and thick (approximately 300 nm) films were spin-coated on hydrophilic silicon wafers. PS films presented scarcely tiny holes, while PS-CTAB and PS-SDS films presented holes and protuberances. The former were attributed to dewetting effects and the latter to surfactant clusters. The films were exposed to water or to a 0.1 mol/L NaCl solution for 24 h. Ex situ measurements evidenced strong topographic alterations after the exposure to the fluid. A model based on the diffusion of water (or electrolyte) molecules to the polymer/silcon dioxide interface through holes or defects on the film edges was proposed to explain the appearance of wrinkles and protuberances. In situ ellipsometric measurements were performed and compared with simulations, which considered either a water layer between a polymer and a silcon dioxide layer or an air layer between a polymer and water (medium). In the case of thin PS films, the ellipsometric angles evidenced a very thin (0.5-1.0 nm) air layer between water and the PS films. Upon increasing the PS film thickness, no air layer could be observed by ellipsometry. Regardless of the thickness, the ellipsometric data obtained for PS-CTAB and PS-SDS films did not indicate the presence of an air layer between them and the aqueous media. The dramatic changes in the topography of PS, PS-CTAB, and PS-SDS after immersion in salt solution were explained with proposed models. From a practical point of view, this study is particularly relevant because many hydrophobic polymers are used as substrates for biomedical purposes, where the physiological ionic strength is 0.15 mol/L NaCl.     

稀土盐对铝合金阳极化过程的影响

在阳极化溶液中添加稀土盐得到的铝合金氧化膜在腐蚀试验中表现出优良的耐蚀性能,现场椭圆法对阳极氧化过程的研究结果表明,稀土盐的加入,对椭圆编振参数的振荡方式没有显著影响,但却使振荡的周期和振幅发生了一些变化,由此可以推知,稀土盐的加入并未改变氧化膜的组成,但却在一定程度上影响了成膜过程,使膜的结构发生了变化。对椭圆数据进行定量分析的结果进一步表明：加入稀土盐后,氧化膜多孔层生长速率加快,阻挡层厚度增加,多孔部分变得更加致密,这种结构上的变化是阳极化膜耐蚀性能得以提高的主要原因,EDAX和TEM分析结果也证实了椭圆法研究的结果。