溶胶凝胶法制备PMMA/SiO2杂化材料

 针对目前PMMA/SiO₂杂化材料制备过程中容易出现的相分离问题，采用原位聚合和同步溶胶凝胶过程制备了聚合物链段与无机组分间有化学键作用的PMMA/SiO₂杂化材料，并应用透射电子显微镜、红外光谱分析仪、X射线衍射分析仪、热失重分析仪等对不同SiO₂含量的PMMA/SiO₂杂化材料的形貌及结构进行了研究。结果表明：SiO₂含量在20%～60%间的PMMA/SiO₂杂化体系没有明显的相分离现象，SiO₂含量在20%～40%间的杂化体系的透光性较好。     

波长1064nm脉冲激光高阈值反射膜的研制

 研究HfO₂/SiO₂高反射膜的制备工艺及其激光诱导损伤阈值的比较测试,分别采用了反应蒸镀HfO₂、反应离子辅助蒸镀HfO₂、反应离子辅助蒸镀金属Hf的源材料形成HfO₂薄膜。采用这三种工艺制备了HfO₂/SiO₂高反射膜,在中心波长1064nm处,反射率 R≥99.5%,其中反应蒸镀HfO₂/SiO₂高反射膜损伤阈值最高,可达60J/cm²(1064nm,5ns)。     

波长1315nm的石英窗口增透膜

 用Ta₂O₅/SiO₂膜系镀制了石英窗口增透膜。并在优化膜系,改进膜厚控制后,使得1315nm波长单面剩余反射率降到0.05%。     

多孔TiO2/Al/SiO2纳米复合结构的紫外光吸收特性研究

在SiO₂玻璃衬底上用脉冲激光沉积(PLD)技术，分别沉积Ti和Ti/Al膜，经电化学阳极氧化成功制备了多孔TiO₂/SiO₂和TiO₂/Al/SiO₂纳米复合结构. 其中TiO₂薄膜上的微孔阵列高度有序，分布均匀. 实验研究了Al过渡层对多孔TiO₂薄膜光吸收特性的影响. 结果表明：无Al过渡层的多孔TiO₂薄膜其紫外吸收峰在27     

SiO2半波覆盖层对HfO2/SiO2高反膜激光损伤的影响

 研究了SiO₂半波覆盖层对HfO₂/SiO₂高反射膜1064nm激光损伤的影响,分析薄膜的激光损伤特性及图貌得出, 对于单脉冲（1-ON-1）激光损伤,SiO₂半波覆盖层能提高HfO₂/SiO₂高反膜的激光损伤阈值;可显著降低激光损伤程度,减小灾难性损伤发生的概率;可大幅度提高HfO₂/SiO₂高反膜膜的抗激光损伤能力。     

光纤白光干涉法与膜厚纳米测量新技术研究

运用薄膜光学干涉原理、光纤技术和干涉光谱分析技术,用光纤反射式干涉光谱仪(Reflectromic Interference Spectroscopy)直接测试宽带入射光在单晶硅表面超薄SiO₂膜层前后界面反射形成的干涉光谱曲线,并用专业软件对被测光谱信号数据处理后,可直接用公式准确计算出SiO₂氧化膜的厚度和光学折射率通过对单晶硅片表面超薄SiO₂氧化膜的实测,并与成熟的椭圆偏振仪测试结果相比,测试误差≤2nm但该方法测试简单、快速,精度高,不需要制定仪器曲线和数表,可对薄膜任意位置的厚度在线测试经过对不同厚度聚苯乙烯薄膜的厚度测试表明,该方法适合0.5～20μm薄膜厚度的精确在线测量,测量误差小于7nm.     

表面层对1 064 nm高反射镜损伤阈值影响

 采用电子束蒸发的方法制备了３种具有不同表面层材料及结构的中心波长为1 064 nm的零度高反镜,３种膜系表面层分别为1/4波长光学厚度的HfO₂,1/2波长光学厚度的SiO₂,以及1/4波长光学厚度的SiO₂。光谱测试表明：三者在1 064 nm处均有较高的反射率（高于99.8%）,利用热透镜的方法测量得到３个膜系辐照激光正入射情况下,薄膜对光的吸收比例分别为3.0×10^-6,5.0×10^-6和6.5×10^-6,其损伤阈值分别为32.5,45.2和28.4 J/cm²。并在膜层内部电场分布和膜层材料物理特性的基础上分析了３种不同表面层膜系吸收和损伤阈值差别的原因。     

LBO晶体上1 064，532 nm倍频增透膜的镀制及性能分析

 用电子束蒸发沉积方法在X切LBO（X-LBO）晶体上镀制了两种不同膜系结构的1 064和532 nm倍频增透膜，其中一种膜系结构为基底/ZrO₂/Y₂O₃/Al₂O₃/SiO₂/空气，另一种为基底/0.5Al₂O₃/ZrO₂/Y₂O₃/Al₂O₃/SiO₂/空气，两种膜系结构的主要差别在于有无氧化铝过渡层。测量了薄膜的反射率光谱曲线，发现两种增透膜在1 064和532 nm处的反射率均小于0.5％，实际镀制结果与理论设计曲线的差异主要是由材料折射率的变化引起的。且对样品在空气环境中进行了温度为473 K的退火处理，结果发现两种膜系结构均表现了较优异的光学性能，氧化铝过渡层的加入使薄膜具有强的热应力性能。     

高功率激光宽光谱减反膜的溶胶-凝胶旋转法制备工艺

 采用溶胶-凝胶法用旋转镀膜工艺在K9玻璃基片上制备出了SiO₂和有机硅单层减反膜以及有机硅-SiO₂双层减反膜。考察了旋转速度对SiO₂和有机硅单层膜的中心透射波长、膜层折射率等基本光学性质的影响，实验确定了双层膜的涂敷工艺。透射光谱测量表明，采用本文工艺条件制备的有机硅 SiO₂双层膜在430～800nm范围内透射率达99％以上。     

层间热处理对SiO2/ZrO2双层膜的影响

 以正硅酸乙酯和丙醇锆为前驱体,用溶胶-凝胶法在K9基片上提拉镀制SiO₂/ZrO₂双层膜。采用不同实验步骤制备了2个样品,样品1镀完SiO₂后直接镀ZrO₂ ,样品2镀完SiO₂经热处理后再镀ZrO₂。采用原子力显微镜、椭偏仪、紫外-可见分光光度计对薄膜进行表征。针对SiO₂/ZrO₂双层膜,考虑到膜间渗透的影响,采用３层Cauchy模型进行椭偏模拟,椭偏参数的模拟值曲线与椭偏仪的测量值曲线十分吻合,进而发现热处理可以使SiO₂/ZrO₂双层膜之间的渗透减少近23 nm,从而提高其峰值透射率。利用输出波长1.064 mm,脉宽8.1 ns的激光束对样品进行了损伤阈值的测试,用光学显微镜观察损伤形貌,结果发现两者损伤阈值分别为13.6 J/c2和14.18 J/cm²,均为膜的本征损伤。     

Formation of hook-shaped and straight silica wires by a thermal vapor method

Hook-shaped and straight silica wires have been successfully synthesized on silicon wafer through a simple thermal vapor method with or without assistance of Al, respectively. The hook-shaped silica wires have amorphous structures with nearly 100 μm long and about 4 μm in average diameters, while the straight silica wires are hundreds of micrometers long and approximately 50–300 nm in diameters. The composition analysis revealed that larger Al/SiO_x islands can form on the silicon substrate with Al catalysts, whereas tiny silica clusters form without Al catalysts. They could act as the nucleation centers for the growth of silica wires with different shapes. The formation process of hook-shaped silica microwire results from a thermal gradient on the silicon substrate. The thermal gradient may be caused by the cold gas flowing during the process or other factors that lead to uneven temperature. On the contrary, straight growth of silica submicrowire is unacted on the thermal gradient factor due to the tiny silica clusters as nucleation centers. The present simple and low-cost process of producing hook-shaped and straight silica wires in bulk may lead to potential applications in catalysts, electrode materials, biosensing, etc.     

Numerical simulation of the modulation to incident laser by the repaired damage site in a fused silica subsurface

One of the main factors of laser induced damage is the modulation to incident laser which is caused by the defect in the subsurface of the fused silica.In this work,the repaired damage site irradiated by CO 2 laser is simplified to a Gaussian rotation according to the corresponding experimental results.Then,the three-dimensional finite-difference time-domain method is employed to simulate the electric field intensity distribution in the vicinity of this kind of defect in fused silica front subsurface.The simulated results show that the modulation is notable,the E max is about 2.6 times the irradiated electric field intensity in the fused silica with the damage site (the width is 1.5 μm and depth is 2.3 μm) though the damage site is repaired by CO 2 laser.The phenomenon and the theoretical result of the annular laser enhancement existed on the rear surface are first verified effectively,which agrees well with the corresponding experimental results.The relations between the maximal electric field intensity in fused silica with defect depth and width are given respectively.Meanwhile,the corresponding physical mechanism is analysed theoretically in detail.     

Surface microstructure and morphology study of thin films produced from volatile fluorine-containing rare-earth β-diketonate complexes and their adducts

We present the results of a surface microstructure and morphology study of thin films produced from volatile fluorine-containing rare-earth β-diketonate complexes and their adducts. Films 0.2–0.4 μm in thickness were synthesized in vacuum by means of thermal deposition of the parent substances at a pressure of 5 × 10^?4?1 × 10^?3 Pa and a deposition rate of 3 × 10^?3 μm s^?1 (for NaNd(FOD)₄ films, the deposition rate was 8 × 10^?2 μm s^?1). The microstructure of films depends on the deposition conditions. The films of [NaNd(PTFA)₄] and [NaNd(FOD)₄] complexes and Ln(PTFA)₃ · S₁ adducts have an amorphous structure. The [NaNd(PTFA)₄(Phen)] and Nd(PTFA)₃ · S₂ films are characterized by a more ordered polycrystalline structure with the grain size ranging from 0.2 to 1.5 μm.     

玻璃微球表面辉光等离子体聚合物涂层的热稳定性研究

采用辉光放电聚合技术,在不同工作压强条件下在直径为350—400 μm,厚度为2.5—3 μm的玻璃微球上制备了辉光放电聚合物 (GDP)涂层,并对玻璃/GDP微球模拟充气过程进行了热稳定性实验.利用傅里叶变换红外光谱仪、元素分析仪、热重法、体视显微镜和X射线照相技术对GDP涂层的内部结构及其化学键、热稳定性、微球形貌和厚度进行了表征.结果表明:GDP涂层中的碳氢比、不饱和键和C C含量随着制备压强的增大而减小,低压的热稳定性较好,GDP涂层与玻璃微球的结合力提高,流变、起泡和脱层现象也得到明显改善.微球 关键词： 玻璃微球 GDP涂层 热稳定性 结合力     

Comparison of magnetoreflection from CoFe-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> multilayer and granular films in the infrared spectral region

The paper reports on a study of light reflection and of the magnetorefractive effect in CoFe-Al₂O₃ multilayer and granular films in the IR region at λ = 2.5–25 μm. These films exhibit a noticeable tunneling magnetoresistance of 5–8%. It has been found that the spectra of the magnetorefractive effect have features at λ ≈ 6.7 and ≈8.1 μm originating from phonon mode excitation in the dielectric matrix. It has been established that the magnitude of the magnetorefractive effect exceeds 2.5% for multilayer films, a value substantially larger than that for granular ones. Magnetoreflection has been analyzed for two film systems with roughly equal tunneling magnetoresistance. It has been shown that magnetoreflection for granular films can be described in a first approximation by the modified Hagen-Rubens relation, while the enhanced effect exhibited by multilayer films requires inclusion of interference of the magnetooptical response.     

Transparent Superhydrophobic silica coatings on glass by sol-gel method

Wetting behavior of solid surfaces is a key concern in our daily life as well as in engineering and science. In the present study, we demonstrate a simple dip coating method for the preparation of Thermally stable, transparent superhydrophobic silica films on glass substrates at room temperature by sol-gel process. The coating alcosol was prepared by keeping the molar ratio of methyltriethoxysilane (MTES), trimethylmethoxysilane (TMMS), methanol (MeOH), water (H₂O) constant at 1:0.09:12.71:3.58, respectively with 13 M NH₄OH throughout the experiments and the films were prepared with different deposition time varied from 5 to 25 h. In order to improve the hydrophobicity of as deposited silica films, the films were derivatized with 10% trimethylchlorosilane (TMCS) as a silylating agent in hexane solvent for 24 h. Enhancement in wetting behavior was observed for surface derivatized silica films which showed a maximum static water contact angle (172°) and minimum sliding angle (2°) for 25 h of deposition time. The superhydrophobic silica films retained their superhydrophobicity up to a temperature of 550 °C. The silica films were characterized by field emission scanning electron microscopy (FE-SEM), surface profilometer, Fourier transform infrared (FT-IR) spectroscopy, thermo-gravimetric and differential thermal analysis (TG-DTA), percentage of optical transmission, water contact angle measurements. The imperviousness behavior of the films was tested with various acids.     

Effect of a positive temperature coefficient of resistance in thin films of doped strontium-barium titanate

Thin films of doped semiconducting barium-strontium titanate (Ba,Sr)TiO₃ are prepared by pulsed laser ablation. It is shown that the crystal structure, morphology, and electrical properties of (Ba,Sr)TiO₃ thin films are determined primarily by the actual ablation conditions. The ablation regimes of deposition permitting preparation of uniform polycrystalline thin films with a composition close to that of the target and with grain sizes larger than 0.1 μm are established. These samples have a positive temperature coefficient of resistance in the phase transition region. The change in the resistivity can be as much as 100%.     

直流三极溅射法制备CuInS2 薄膜

采用直流三极溅射装置制备获得了CuInS₂薄膜, 其中溅射靶采用一定面积比的[Cu]/[In]混合靶,反应气体采用CS₂气体. 本文中主要研究了0.02 Pa分压反应气体条件下不同面积比的[Cu]/[In]混合靶和沉积基板温度对CuInS₂薄膜结构和成分的影响, 其中CuInS₂薄膜制备所用时间为2 h生长的厚度为1—2 μm. 通过对CuInS₂薄膜的EPMA, X射线衍射测试分析表明, 最佳的CuInS₂薄膜可在面积比[Cu]/[In]混合靶为1.4:1和可控温度(150, 250和350 ℃)的条件下制备获得, 并且其结构被确认为黄铜矿结构. 通过实验结果计算出CuInS₂薄膜层有约为8.9%的C杂质含量.     

Large grained and high charge carrier lifetime CH3NH3PbI3 thin-films: implications for perovskite solar cells

Spin coated perovskite thin films are known to have an issue of pinholes & poor morphology control which lead to poor device-to-device repeatability, that is an impediment to scale-up. In this work, Methylamine vapor annealing process is demonstrated which consistently leads to high-quality perovskite thin-films with an average grain-size of 10–15 μm. The improvement in film morphology enables improvement in effective carrier recombination lifetime, from 21 μs in as-deposited films to 54 μs in vapor-annealed films. The annealed films with large-grains are also more stable in ambient conditions. Devices made on annealed perovskite films are very consistent, with a standard deviation of only 0.7%. Methylamine vapor annealing process is a promising method of depositing large-grain CH₃NH₃PbI₃ films with high recombination lifetime and the devices with improved performance.     

纳米β-FeSi2/a-Si多层膜室温光致发光分析

采用射频磁控溅射的方法,在Si（100）基片上制备了纳米β-FeSi₂/Si多层结构,利用X射线衍射、透射电子显微镜、光致发光光谱等表征技术,研究了β-FeSi₂/Si多层结构的结构、成分和光致发光特性.研究结果表明：利用磁控溅射法得到的Fe/Si多层膜,室温下能够检测到β-FeSi₂的1.53 μm处光致发光信号;未退火时多层膜是（非晶的FeSi₂+β-FeSi₂颗粒）/非晶Si结构,退火后则是 关键词： 2')" href="#">β-FeSi₂ 磁控溅射 XRD 光致发光光谱