ZnO薄膜非线性光学特性的实验研究

利用金属有机化学气相沉积(MOCVD)技术在蓝宝石衬底上生长一层高质量的ZnO薄膜。为了考察沉积温度对样品的非线性特性的影响,在200~500 ℃生长了一系列ZnO薄膜。用X射线衍射谱(XRD)及扫描电镜(SEM)对样品结构进行了评价。以Nd:YAG激光器输出的1.06 μm的激光为基频光,对ZnO薄膜样品的二阶及三阶非线性光学特性进行了实验研究。实验发现,对于250 ℃沉积温度的样品有较强的非线性效应,实验测得的二阶非线性极化张量 χ ⁽²⁾_ZZZ=9.2 pm/V, 三阶有效非线性系数χ⁽³⁾=5.28×10^－20 m²/V²。     

阶段离子束辅助法制备基频减反膜

在研究阶段离子束辅助制备方式对薄膜性质影响的基础上,采用电子枪蒸发及离子束辅助沉积制备了氧化铪及氧化硅单层膜,采用阶段离子束辅助沉积及全程非离子束辅助沉积制备了基频减反膜。测量了所有样品的弱吸收、残余应力和激光损伤阈值。结果发现,相对电子枪热蒸发制备的样品,离子束辅助沉积的单层膜具有大的弱吸收、低的激光损伤阈值,且张应力减小,压应力增加;阶段离子束辅助沉积制备的减反膜剩余应力变小,弱吸收稍微增加,激光损伤阈值从10.91 J/cm²增加到18 J/cm²。分析表明,离子束辅助沉积在引入提高样品激光损伤阈值有利因素的同时,也引入 了不利因素,阶段离子束辅助沉积在引入有利因素的同时,有效减少了不利因素的引入,从而提高了样品的激光损伤阈值。     

铌硼酸盐玻璃网络结构的研究

用径向分布函数和红外光谱分析方法研究了2Nb₂O₅·4B₂O₃·4K₂O和1.5Nb₂O₅·45B₂O₃·3.5K₂O·0.5TiO₂等玻璃的网络结构.得出了铌原子和硼原子的配位数分别为5.8～5.6及3或4.在原子分布函数g(r)和径向分布函数RDF(r)曲线中得出了Nb-O键平均键长为1.92～1.88Å.位于3.11,3.17和3.85Å的其它峰分别是Nb-B,O-O,和Nb-Nb原子对间的距离.红外光谱表明每种玻璃对应的各吸收峰,归结为=B-O(1440和1220cm^-1),≡B-O(1040或920cm^-1),Nb-O(870、730cm^-1)及Nb-O-B(1330cm^-1)的键振动.也就是说,在网络结构中六配位的铌原子与四配位和三配位的硼原子是共存的.这里,四配位的硼分数N₄决定于K₂O和Nb₂O₅的含量.而且与布雷用核磁共振法在B₂O₃-K₂O系统玻璃中的研究结果相符.最后,在对实验数据的分析和计算的基础上提出了NBK玻璃网络结构的一个可能的模型.认为铌硼酸盐玻璃的网络结构是由NbO₅、BO₄和BO₂共同组成的六节和四节环状结构单位元所构成的.     

CW可调谐单频环形染料激光器β-BaB2O4晶体内腔倍频

本文论述了利用β-BaB₂O₄晶体进行内腔连续波环形染料激光器倍频,获得了可调谐单频紫外相干辐射。在292nm附近,用3WAr⁺激光(全谱线)泵浦,得到非线性转换系数～8.33×10^-4W^-1。通过改变相位匹配角,在288～302nm范围内输出连续可调谐紫外谐波。β-BaB₂O₄晶体角灵敏度～27cm^-1/mrad。     

特气室温红外探测器的噪声分析

由MEMS技术制备的特气室温红外探测器的噪声主要包括温度噪声、机械热噪声和背景噪声。从理论上建立了器件的基本热模型,推导得到器件的等效热熔和等效热导分别为8.1 μJ/K和1.0×10^-3 W/K,温度噪声约为1.73×10^-10 W/Hz^1/2;通过器件的工作机理和能量均分原理,推导得到热机械噪声的等效噪声功率约为9.96×10^-9 W/Hz^1/2,器件的背景噪声约为3.22×10^-11 W/Hz^1/2,从而得出器件的归一化探测率约为9.03×10⁶ cm·Hz^1/2/W。实验表明,器件的噪声中热机械噪声为主要噪声源,大小主要由浓硼硅薄膜的机械性能和器件结构决定,可以通过增大薄膜厚度,减小薄膜面积,从而增加薄膜的特征频率的方法来减小器件受外界振动的影响,但以降低器件的灵敏度为代价。另外环境振动噪声也对器件的影响很大。为了减小外界气压和温度变化的影响,提出了一种新型的双腔结构来减小和平衡外界环境变化引入的噪声。     

光学玻璃的折射率测定

本文介绍测定光学玻璃的折射率用的两种仪器的设计。制造光学玻璃的生产单位必需有两种测定折射率的方法。这些方法是:(1)给出折射率的精度为±1×10^-5的快速和精确的方法,和(2)能得到±1×10^-6的较精确的系统。介绍的第一种方法是光电 V 块系统,而第二种是利用电子条纹计数的双光束干涉系统。     

稀土光学玻璃着色的研究

本文系统地测定了第一过渡金属(Fe,Co,Ni,Cu,Cr,Mn 等)离子和稀土(Ce,Pr,Nd,Sm 等)着色离子在 B₂O₃-BaO,B₂O₃-La₂O₃-BaO,B₂O₃-BaO-SiO₂,B₂O₃-BaO-SiO₂-La₂O₃及氟磷等系统玻璃中的吸收光谱。比较了各种着色离子对不同系统玻璃的着色情况。阐述了3d 轨道部分填充的过渡金属离子及具有4f 壳层受5s,5p 电子层屏蔽的 Ce,Pr,Nd,Sm 离子在玻璃中的着色机理。并讨论了玻璃生成体B^a+,si⁴⁺,P⁵⁺阳离子及网络外体离子 La³⁺,F^-对玻璃着色的影响。最后提出了稀土玻璃中稀土杂质含量的允许值。     

铜锌合金及20CrMnTi钢中温塑性加工的规律和机理的研究

本文研究了H68黄铜和20CrMnTi 钢的动态应变时效(DSA)和动态退火(DA)对其机械性能的影响。试验是在300—1100K 的温度范围内进行的,应变速度为1.1×10^-2s^-1到1.1×10^-4s^-1,平均晶粒尺寸为10μm。试验结果表明:H68黄铜的最大均匀应变量和加工硬化参数均在某一温度范围内出现一个峰值,而20CrMnTi 钢则在高温区和低温区分别形成一个峰值。试验的另一个结果是发现动态应变时效现象与动态退火现象在靠近临界温度时有一定的重叠。建议在研究中温塑性加工的规律时,有必要考虑这两种现象的影响。     

差动电磁作动器的超大型光学仪器 隔振基础的主动控制机理

提出了一种基于差动电磁作动器的超大型光学仪器隔振基础的主动控制机理。该控制机理采用差动布置方案,使电磁作动器变为输出力和控制电流呈线性关系的线性作动器,再利用小阻尼条件下,绝对速度反馈与Skyhook控制方法性能接近且易于工程实现的特点,采用了绝对速度反馈的控制方法,可在不改变中/高频隔振性能的前提下大幅提高谐振区隔振性能。实验结果表明:利用所提出的控制机理,在时域上,z、θ_x和θ_y三个自由度的速度(角速度)均方根值分别由10.06 μm/s、4.16×10^－6rad/s和4.65×10^－6rad/s降至3.38 μm/s、1.76×10^－6rad/s和1.49×10^－6rad/s;在频域上,三个自由度谐振区隔振性能均有约10 dB的提高。     

Mg(PO3)2-BaF2-AlF3系统玻璃的振动谱研究

应用红外及拉曼光谱研究了Mg(PO₃)₂-BaF₂-AlF₃系统氟磷玻璃的结构特征.证实了双键氧(P=O)及由Al(O.F)₄四面体和P(O.F)₄四面体所混合构成的网络结构存在于玻璃之中.在拉曼光谱中,V_Ba-F、V_Mg-F和V_Al-F振动吸收峰分别出现在480-510cm^-1、530-550cm^-1和580cm^-1处.根据红外及拉曼光谱的结果得出:随系统中氟化物含量的增加,玻璃结构逐渐由聚磷酸盐转变为焦磷酸盐和一氟正磷酸盐混合物,同时双键氧(P=O)消失.     

透明导电ITO薄膜的制备及光电特性的研究

采用溶胶-凝胶方法以In（NO3）3.4·5H2O和SnCl4·5H2O为前驱物,用提拉法在石英玻璃基体上制备了ITO透明导电薄膜。详细研究了不同掺Sn比例、不同金属离子浓度、不同提拉速度、不同烘烤温度对ITO薄膜光电特性的影响。结果表明,提拉法制备的薄膜在热处理过程中由凝胶状态向结晶态逐渐转变,方电阻随热处理温度的升高而降低;导电率随薄膜厚度的增加呈非线性增加。     

ITO thin films prepared by electron beam evaporation with End-Hall ion source assisted without heating to the substrate

1Introduction ITO(indiumoxidedopedwithtin)trans parentconductingfilmshaveuniqueopticaland electricalpropertiesofhightransmittanceinthe visibleregionandstrongreflectanceintheinfra redregionaswellastheexcellentconductivity.Forthesecharacteristics,ITOfilmsplayanim portantroleinthefieldofoptoelectronicde vices,suchastransparentelectrodeforelectro magneticinterference(EMI)shielding,electro chromicwindow[1],liquidcrystaldisplays(LCD)[2],andarchitecturalapplications.Ava rietyofthinfilmdepositiont…     

A system for supplying constant electrical power for postprocessing tin-doped indium oxide films

Annealing tin doped indium oxide (ITO) thin films by self-heating shows potential for reducing the crystallization temperature required to optimize the optical and electrical properties of the films. It also shows promise as a cost effective method of studying the heat treatment process in situ. A computer based solution was developed to allow for a precise control over the annealing process. To anneal at a fixed temperature, a feedback loop senses changes in the resistance of the sample and adjusts the current across the load accordingly to ensure constant delivery of power to an ITO film.     

The role of substrates on the structural,optical, and morphological properties of zno nanotubes prepared by spray pyrolysis

ZnO films were deposited onto glass, ITO coated glass, and sapphire substrate by spray pyrolysis, and subsequently annealed at the same temperature of 400°C for 3 h. The role of substrate on the properties of ZnO films was investigated. The structural and optical properties of the films were investigated by X‐ray diffractometer (XRD) and photoluminescence (PL) spectrophotometer, respectively. The surface morphology of the nanostructured ZnO film was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Crystallographic properties revealed that the ZnO films deposited on sapphire and ITO substrates exhibit a strong c‐axis orientation of grains with hexagonal wurtzite structure. Extremely high UV emission intensity was determined in the film on ITO. The different luminescence behaviors was discussed, which would be caused by least value of strain in the film. Films grown on different substrates revealed differences in the morphology. ZnO films on ITO and sapphire substrates revealed better morphology than that of the film on glass. AFM images of the films prepared on ITO show uniform distribution of grains with large surface roughness, suitable for application in dye sensitized solar cells. Microsc. Res. Tech. 77:211–215, 2014. © 2013 Wiley Periodicals, Inc.     

A Simple Laboratory Method to Pattern Sub‐Millimeter Features of Conductive Films of Gold and Indium Tin Oxide

Abstract

A simple laboratory photolithography method for patterning 100 nm thick gold and indium tin oxide (ITO) films on glass slides with 100 µm resolution without the need of special equipment is described. During the procedure, the conductive films are coated with a commercial screen printing emulsion using a modified drill as spin‐coater, then placed in contact with a negative photomask, and exposed to a 20 W light source for 30–60 min. The excess photoresist is washed off with water, and the glass slides are baked at 210°C to produce a mechanically and chemically resistant coating. The substrates are then etched in dilute aqueous HNO₃/HCl (gold) or 6 n HCl (ITO) to remove exposed gold and ITO films. After etching, the photoresist is removed by etching with peroxosulfuric acid (gold) or scraped off with a razor blade (ITO) leaving a conductive pattern. The procedure requires between 3 and 5 h of time, depending on experience.     

Influence of gallium‐doped zinc‐oxide thickness on polymer light‐emitting diode luminescence efficiency

Conducting atomic force microscopy and scanning surface potential microscopy were used to study the local electrical properties of gallium‐doped zinc oxide (GZO) films prepared by pulsed laser deposition (PLD) on a polyimide (PI) substrate. For a PLD deposition process time of 8 min, the root‐mean‐square roughness, coverage percentage of the conducting regions, and mean work function on the GZO surface were 2.33 nm, 96.6%, and 4.82 eV, respectively. When the GZO/PI substrate was used for a polymer light‐emitting diode (PLED), the electroluminescence intensity increased by nearly 20% compared to a standard PLED, which was based on a commercial‐ITO/glass substrate. Microsc. Res. Tech. 76:783–787, 2013. © 2013 Wiley Periodicals, Inc.     

一种基于ITO涂层的电梯安全间隙测量仪器的设计

开发了一款基于ITO涂层的电梯安全间隙测量仪器。该仪器采用IC芯片对ITO涂层的电信号进行采集和处理,在微型显示器上直接显示电梯安全间隙测量数值结果。该仪器操作简单,体积小,便于携带,测量结果符合检规和标准要求,测量精度高,提升了现场检验的质量和效率。     

High-conductivity amorphous TiSi substrates for low-temperature electron microscopy

To avoid problems with electrostatic charging, electrically conductive specimen support films or coatings must be used when observing non-conductive organic specimens by electron microscopy. At room temperature, microscopists typically use either carbon films or carbon-coated plastic films as specimen substrates. Such films have also been adopted for low-temperature microscopy. Recent measurements have shown that conventional carbon films have high electrical resistivity at low temperature. Thin titanium films have been used to provide improved electrical conductivity, but the structure of titanium films is excessively granular for high-resolution electron microscopy. With the hope of solving both problems, thin films of Ti₈₈Si₁₂ have been produced using a standard evaporation system. The deposited films are amorphous, as shown by electron microscopy, electron diffraction and differential scanning calorimetry. The electrical conductivity of the binary alloy films is nearly as high as that of pure titanium films. Therefore, these films appear to be appropriate substrates for low-temperature electron microscopy.     

Growth and characterization of V2O5 thin film on conductive electrode

Vanadium pentoxide V₂O₅ thin films were grown at room temperature on ITO coated glass substrates by electrochemical deposition. The resulting films were annealed at 300, 400 and 500°C for 1 h in ambient environment. The effect of heat treatment on the films properties such as surface morphology, crystal structure, optical absorption and photoluminescence were investigated. The x‐ray diffraction study showed that the films are well crystallized with temperatures. Strong reflection from plane (400) indicated the film's preferred growth orientation. The V₂O₅ films are found to be highly transparent across the visible spectrum and the measured photoluminescence quenching suggested the film's potential application in OPV device fabrication.     

A magnetron sputtering system for the preparation of patterned thin films and in situ thin film electrical resistance measurements

We describe a versatile three gun magnetron sputtering system with a custom made sample holder for in situ electrical resistance measurements, both during film growth and ambient changes on film electrical properties. The sample holder allows for the preparation of patterned thin film structures, using up to five different shadow masks without breaking vacuum. We show how the system is used to monitor the electrical resistance of thin metallic films during growth and to study the thermodynamics of hydrogen uptake in metallic thin films. Furthermore, we demonstrate the growth of thin film capacitors, where patterned films are created using shadow masks.