多孔SiO2膜的制备和增透性能研究

采用溶胶-凝胶结合旋转涂膜法在玻璃基底上制备SiO2薄膜,研究了陈化时间和旋涂速度对SiO2膜增透性能的影响,利用热分析仪、X射线衍射仪、红外光谱仪、扫描电镜、分光光度计、椭偏仪等方法分别对干凝胶的热分解过程、晶体结构、微观形貌、透过率和折射率进行表征.结果表明:膜层透过率与制备条件有一定的规律,随着陈化时间的延长和旋涂速度的增加,增透峰中心波长发生了移动.在最佳工艺条件下,制备的SiO2薄膜具有较好的增透性能,在玻璃上镀SiO2增透膜后,峰值透过率(300～1000 nm)由90％提高到95％,其膜厚为315 nm,折射率为1.352,孔隙率为27％,进一步提高了可见光利用率.     

疏水性SiO2增透膜的制备与表征

以三甲基氯硅烷（TMCS）为有机掺杂剂,采用溶胶-凝胶法制备正硅酸乙酯为前驱体,氨水催化的复合SiO2增透膜。用紫外-可见分光光度仪、接触角测量仪对膜层进行了表征。结果表明：未经TMCS掺杂的SiO2增透膜的峰值透过率为97．5％,而一定浓度TMCS掺杂后的SiO2复合膜的峰值透过率为983％,说明掺杂并没有影响薄膜的增透效果。掺杂前后增透膜对水的接触角从15°增加到123°,显著的提高了薄膜的疏水性能。     

Y_2O_3∶ Nd透明陶瓷的制备

以氧化钇、氧化钕和碳酸氢铵为原料,制备出了前驱物经煅烧后颗粒尺寸为40～60 nm的Y_2O_3∶ Nd纳米粉体.该粉体先模压成型、再经冷等静压成型,通过真空烧结和热等静压成功制备出红外平均透过率达72%的Y_2O_3∶ Nd透明陶瓷.     

甲基三甲氧基硅烷修饰对SiO2增透膜耐候性能的影响研究

以正硅酸乙酯(TEOS)为前驱体、甲基三甲氧基硅烷(MTMS)为修饰剂,利用酸催化的方法制备了SiO₂增透膜液。采用浸渍提拉法在玻璃基片上进行镀膜,利用马弗炉对膜层进行固化处理,所得膜层通过冷凝水试验箱和TABER磨耗仪进行了耐水和耐磨测试,从而研究了MTMS的加入量对SiO₂增透膜透过性能及耐候性能的影响。结果表明：适量MTMS的加入可提高SiO₂增透膜的透过性能,当n(MTMS)/n(TEOS)=0.5时,其增透性能由未加MTMS时的5.2%增加到5.8%,增长了11.5%,而随着MTMS加入量的增多,增透性能又会呈现下降的趋势;MTMS的加入还在很大程度上改善了SiO₂增透膜的耐水性能,当n(MTMS)/n(TEOS)≥1时,500 h的冷凝水实验对膜层表面及透过性能几乎无影响;随着MTMS加入量的逐步增加,膜层耐磨性能也会逐步地提升,当n(MTMS)/n(TEOS)=2时,膜层经100次循环摩擦后透过率增加量仅降低10%,相比未加MTMS的膜层而言,其耐磨性能有了大幅提升。     

应用于ZnS、ZnSe和硫系玻璃表面的类金刚石膜研究进展

类金刚石膜(Diamond-like Carbon film,DLC)硬度高,摩擦系数小,抗摩擦磨损和化学腐蚀能力强,同时在中远红外波段有良好的透过性能,用于红外窗口表面,可以起到良好的增透和物理防护效果。本文总结了近十年来应用于ZnS、ZnSe和硫系玻璃表面DLC膜的研究进展,展示了DLC膜在红外领域的应用前景,为红外DLC膜的进一步应用和发展提供借鉴。     

SnO2∶Sb/SiO2复合薄膜的制备与光学性能

采用溶胶-凝胶结合旋涂技术在玻璃基底上制备了SnO2∶Sb/SiO2复合薄膜,利用XRD、FT-IR、SEM、椭偏仪、分光光度计等方法对薄膜样品进行了系统地表征。结果表明:经过热处理后样品生成了SnO2∶Sb和SiO2;薄膜具有双层结构,上层SiO2厚度约105 nm,折射率为1.352,底层SnO2∶Sb厚度约1200 nm,折射率为1.91;优化工艺条件下SnO2∶Sb/SiO2复合薄膜的性能优于SnO2∶Sb薄膜,在相同情况下SnO2∶Sb/SiO2复合薄膜对可见光的透过率大于SnO2∶Sb薄膜,这是因为上层SiO2薄膜折射率较低,与底层高折射率SnO2∶Sb薄膜共同构成减反射膜系,提高了膜系的可见光透过率。相比于单层SnO2∶Sb膜,在可见光部分增透率大于4.5%,近红外波段的增透率小于1.0%,基本保持原有导电膜的低红外辐射特性,并提高了可见光透过率。     

不同ATO掺量对SiO2/ATO-SiO2疏水型抗静电增透膜性能的影响

采用溶胶-凝胶法分别制备SiO2增透溶胶与疏水型抗静电薄膜溶胶.将锑掺杂氧化锡(ATO)掺入硅溶胶,并利用六甲基二硅氮烷(HMDS)对溶胶进行疏水改性.采用提拉镀膜法在玻璃表面首先制备了一层SiO2增透膜,然后在SiO2增透膜表面制备了一层具有疏水与抗静电性能的薄膜.结果表明:当ATO掺量在10％ ～20％时,双层薄膜具有比单层SiO2增透膜更高的透过率,在可见光范围内,平均透过率最高可达93％,峰值透过率为94.6％;薄膜与水的接触角最高可达到95.7°;薄膜表面电阻在106Ω/□以下.     

CVD金刚石衬底上抗氧化、增透膜的制备与性能

采用射频磁控反应溅射法在化学气相沉积(chemical vapor deposition,CVD)的金刚石衬底上制备了AlN薄膜以及AlN/Si和AlN/Ge膜。通过X射线衍射分析了衬底加热温度对薄膜微结构的影响和薄膜高温下的氧化行为。结果表明:在衬底加热温度低于380℃时制备的AlN薄膜为非晶态,480℃时AlN薄膜为六方多晶。AlN薄膜在800℃热暴露后开始氧化,900℃时基本被氧化为Al2O3。在CVD金刚石上制备的AlN/Si和AlN/Ge膜都能提高金刚石在长波红外波段(8～10μm)的透过性能,单面最大增透分别为8%和3%。镀有AlN/Ge膜的CVD金刚石在800℃高温热暴露实验中,有AlN/Ge膜保护的金刚石表面未发生刻蚀。高温下AlN/Ge膜对金刚石有很好的保护作用,同时增透效果没有明显下降。     

红外透明MgO–Y_2O_3纳米复相陶瓷研究进展

针对未来高马赫数导弹的发展趋势及红外窗口材料所面临的技术挑战,对比分析了当前几种常见的红外窗口材料。Mg O–Y_2O_3纳米复相陶瓷具有出色的中波红外透过性能、极低的高温辐射系数、优良的高温力学性能、适中的热学性能以及仅次于蓝宝石的抗热震性,使其有望成为未来高马赫数导弹红外窗口/整流罩的最佳候选材料。同时着重对Mg O–Y_2O_3纳米复相陶瓷的研究进展及其设计原理、制备方法和材料性能等做了综述和介绍,最后对其发展前景做了展望与分析。减小Mg O–Y_2O_3纳米复相陶瓷的晶粒尺寸有望实现该材料在可见光波段的应用,其力学性能也将进一步增强。真空烧结配合热等静压烧结的工艺路线有利于实现大尺寸、近净尺寸成型制备。     

氮化碳超硬防划伤镀膜玻璃的制备与研究

采用工业磁控溅射设备在玻璃基板上依次沉积Al_2O_3/SiO_2/CNx多层复合纳米薄膜,并研究测试了其透过率、耐划性及耐酸碱性。结果表明,通过引入线性阳极层离子源,控制并形成新的磁控溅射镀膜工艺,膜层莫氏硬度达到8级,具有优良的防刮效果;膜层存在△T0.6%的微弱增透效果;经过酸/碱处理,透过率衰减|ΔT|0.1%。     

Tuning the peak position of subwavelength silica nanosphere broadband antireflection coatings

Subwavelength nanostructures are considered as promising building blocks for antireflection and light trapping applications. In this study, we demonstrate excellent broadband antireflection effect from thin films of monolayer silica nanospheres with a diameter of 100 nm prepared by Langmuir-Blodgett method on glass substrates. With a single layer of compact silica nanosphere thin film coated on both sides of a glass, we achieved maximum transmittance of 99% at 560 nm. Furthermore, the optical transmission peak of the nanosphere thin films can be tuned over the UV-visible range by changing processing parameters during Langmuir-Blodgett deposition. The tunable optical transmission peaks of the Langmuir-Blodgett films were correlated with deposition parameters such as surface pressure, surfactant concentration, ageing of suspensions and annealing effect. Such peak-tunable broadband antireflection coating has wide applications in diversified industries such as solar cells, windows, displays and lenses.     

Preparation of AlN and LiNbO3 thin films on diamond substrates by sputtering method

Diamond is attracting interest as a high velocity material because its elastic constant is the highest of all substances and the surface acoustic wave (SAW) velocity is more than 10 000 m/s. Although diamond is not piezoelectric, its high acoustic propagation makes it a desirable substrate for SAW devices when coupled with piezoelectric thin films such as aluminum nitride (AlN) and lithium niobate (LiNbO₃). Highly oriented AlN thin films and LiNbO₃ thin films were prepared by a reactive sputtering method on polycrystalline diamond substrates. The average surface roughness (Ra) of the AlN thin films was below 2 nm by locating the diamond substrates at the position of 100 mm from the aluminum target. The full width at half maximum of the rocking curve for the AlN(002) peak of X-ray diffraction was approximately 0.2°. SAW characteristics with an interdigital transducer (IDT)/AlN/diamond structure were investigated. The average surface roughness of LiNbO₃ thin films was 5 nm. If the highly oriented LiNbO₃ films are deposited on a diamond substrate, the IDT/LiNbO₃/diamond layered structure will be capable of wide-bandwidth application in SAW devices at high frequencies.     

Effect of annealing on grain growth and Y segregation behavior in tetragonal ZrO2 thin film

In order to fabricate tetragonal yttria stabilized zirconia samples with large grain size, 3 mol% Y₂O₃ doped zirconia thin films were grown on (0001) α-Al₂O₃ substrate by pulsed laser deposition (PLD) followed by subsequent high temperature annealing. The thin film samples were annealed at 1200°C, 1250°C, 1300°C, and 1350°C in order to obtain larger grain size without Y segregation. The microstructure and chemical composition of these annealed films were analyzed using atomic force microscopy, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The as-grown thin film was found to be composed of [111]-oriented grains of ∼100 nm connected with small-angle tilt boundaries. Based on analysis of annealed thin films, it was revealed that grain growth of tetragonal zirconia occurred anisotropically. Cross section scanning transmission electron microscopy observations revealed that such grain growth behavior is affected by the step-terrace structures of the sapphire substrate. Energy-dispersive X-ray spectroscopy showed that Y was found to distribute almost uniformly below 1300°C but to segregate at the grain boundaries at 1350°C. As a conclusion, the 1300°C-annealed sample shows the largest grain size with homogeneous Y distributions.     

空气和氮气气氛中热处理温度对ITO薄膜性能影响

以InCl_3·4H_2O和SnCl_4·5H_2O为主要原料,采用溶胶-凝胶法和旋转涂膜工艺。在玻璃基片上制备掺锡氧化铟透明导电薄膜(ITO),采用x-射线粉末衍射、紫外-可见透射光谱和四探针技术,研究了在空气和氮气气氛中,不同热处理温度对ITO薄膜的微结构、光学和电学性能的影响。     

Atomic layer deposition of Al2O3 thin films on diamond

Atomic layer deposition (ALD) of aluminum oxide thin films on diamond was demonstrated for the first time, and the film properties as a gate insulator for diamond field effect transistor (FET) were examined. The interface between the aluminum oxide and the diamond was abrupt, and the ratio of aluminum to oxygen in the film was confirmed to be stoichiometric by Rutherford back scattering. Even a bumpy surface of polycrystalline diamond film was conformally covered by the Al₂O₃ films. To evaluate the feasibility of the film for FET gate insulator, the electrical characteristics of the Al₂O₃ films deposited by ALD on diamond were measured using metal–insulator–semiconductor structure. It was found that the Al₂O₃ films deposited by ALD were better than those deposited by conventional methods, which indicates that the ALD-Al₂O₃ films are feasible for gate insulators of diamond FETs.     

Thermal diffusivity measurements by “instantaneous phase portrai” method

A new method of “instantaneous phase portrait” was developed for measurements of thermal diffusivity χ of thin films with high values of χ, such as diamond films. This method is based on the registration of the air layer refractive index spatial distribution by means of double exposure holographic interferometry and the derivation of the thermal diffusivity value χ from the spatial distribution. The values of thermal diffusivity for copper and steel foils measured by this technique coincide with the tabular ones. The method was also applied to measure thermal diffusivity of thin diamond films. The measured values were in 2–3 cm² s⁻¹ range.     

Alumina atomic layer deposition nanocoatings on primary diamond particles using a fluidized bed reactor

Ultra-thin alumina films are successfully deposited on primary micron-sized diamond particles in a scalable fluidized bed reactor. The studies of fluidization at reduced pressure show that micron-sized diamond particles can be fluidized with the assistance of vibration. Alumina films are grown at 177 °C by atomic layer deposition (ALD) using sequential exposures of Al(CH₃)₃ and H₂O. The deposited alumina films are characterized by X-ray photoelectron spectroscopy, transmission and scanning electron microscopy, inductively coupled plasma-atomic emission spectroscopy, and surface area. The results indicate that the alumina films are conformally coated on the primary diamond particle surface, and the growth rate of alumina is 0.12 nm per coating cycle.     

在ITO玻璃衬底上制备锆钛酸铅铁电薄膜

利用射频反应性溅射沉积技术在掺的Ｓｎ的Ｉｎ２Ｏ３导电透明膜衬底上制备了钙钛矿型Ｐｂ（Ｚｒ,Ｔｉ）Ｏ３（ＰＺＴ）铁电薄膜。研究了沉积参量与热处理工艺对铁电薄膜结构和性能的影响。运用Ｘ射线衍射、Ｘ射线光电子能谱和扫描电镜等技术,分析了薄膜的晶体结构、表面形貌和表面元素化学状态。测量了不同处理条件下薄膜的铁电性能。结果表明：在掺Ｓｎ的Ｉｎ２Ｏ３导电透明膜衬底上可以得到表面无裂纹,化学计量比符合要求的ＰＺ     

Pb-Diffusion Barrier Layers for PbTiO3 Thin Films Deposited on Si Substrates by Metal Organic Chemical Vapor Deposition

The interfaces between metal organic chemical vapor deposited PbTiO₃ thin films and various diffusion barrier layers deposited on Si substrates were investigated by transmission electron microscopy. Several diffusion barrier thin films such as polycrystalline TiO₂, amorphous TiO₂, ZrO₂, and TiN were deposited between the PbTiO₃ thin film and Si substrate, because the deposition of PbTiO₃ thin films on bare Si substrates produced Pb silicate layers at the interface irrespective of the deposition conditions. The TiO₂ films were converted to PbTiO₃ by their reaction with diffused Pb and O ions during PbTiO₃ deposition at a gubstrate temperature of 410°C. Further diffusion of Pb and O induces formation of a Pb silicate layer at the interface. ZrO₂ did not seem to react with Pb and O during PbTiO₃ deposition at the same temperature, but the Pb and O ions that diffused through the ZrO₂ layer formed a Pb silicate layer between the ZrO₂ and Si substrate. The TiN films did not seem to react with Pb and O ions during the deposition of PbTiO₃ at 410°C, but reacted with PbTiO₃ to form a lead-deficient pyrochlore during postdeposition rapid thermal annealing at 700°C. However, TiN could effectively block the diffusion of Pb and O ions into the Si substrate and the formation of Pb silicate at the interface.     

磁控反应溅射制备钇掺杂TiO_2薄膜的研究

采用混合靶直流磁控反应溅射法,在玻璃基体上溅射沉积了含有氧化钇的TiO2薄膜.X-射线光电子能谱分析结果表明,薄膜是由Y2O3和TiO2复合氧化物组成的.钇的存在会抑制薄膜中二氧化钛晶体的形成.薄膜的紫外可见光谱透射率略有下降,而反射率有所增加.钇的掺杂对二氧化钛薄膜的光催化活性起负作用,光催化降解甲基橙反应的活性随钇含量的增加而下降.