蒸发条件对碘化铅多晶薄膜结构的影响

采用真空蒸发法在普通玻璃上制备了PbI₂多晶薄膜.研究了蒸发速率、蒸发源与衬底距离、薄膜厚度以及衬底温度等实验条件对所制备PbI₂多晶薄膜结构的影响.利用X射线衍射仪和扫描电子显微镜对样品进行了测试.结果表明，在衬底温度为室温时得到(001)择优取向的多晶PbI₂薄膜，即沿c轴垂直衬底方向取向生长的薄膜.当衬底温度升高时，薄膜的择优取向逐渐由(001)转向(003)，且晶体颗粒变大.薄膜中的内应力随衬底温度的升高而降低.     

Ge-Sb-Se硫系薄膜制备及光学特性研究

介绍了几种常见的硫系薄膜制备方法, 根据现有实验条件采用热蒸发法和磁控溅射法制备出Ge-Sb-Se三元体系硫系薄膜, 通过台阶仪测试薄膜的厚度和表面粗糙度, 计算出两种制备方法的成膜速率, 并通过X射线光电子能谱测试了两种制备方法所得薄膜与块体靶材组分的差别. 利用Z扫描技术和分光光度计测试了热蒸发法制备所得薄膜的三阶非线性性能和透过光谱, 计算出非线性折射率、非线性吸收系数和薄膜厚度等参数. 结果表明热蒸发法制备Ge-Sb-Se薄膜具有良好的物理结构和光学特性, 在集成光学器件方面很高的应用潜力.     

埋藏于有机介质中金属原子团的结构研究(I)

利用双源同时蒸发和U型管热壁蒸发法制备了两种金属-有机复合薄膜Ag-7,7,8,8-tetracyanoquinodimethane和Ag-1,4-bis-(1,1-dicyanovinyl)-benze.利用透射电子显微镜和可见—紫外光谱研究了所制备的金属-有机复合薄膜的结构特性，发现它们是一种金属原子团埋藏于具有π-共轭体系的有机介质中的薄膜体系. 关键词：     

非线性光学中的新型有机和聚合分子材料

近年来的研究成果表明在非线性光学中一些有机和聚合分子材料与相应的无机晶体、半导体如LiNbO₃、GaAs等相比较,具有许多优越性。本文介绍了一些有机和聚合分子材料的非线性光学效应,包括模拟,离散和双稳现象及其潜在的应用。然后描述了几种这类晶体与薄膜材料的制备技术,其中LB膜沉积是制备超薄有机聚合膜的有效方法。     

有机薄膜1/4波片

<正> 波片是研究偏振光的重要光学元件,在激光实验中更常使用。通常它是用单轴双折射晶体(如石英)或便于剥制的双轴晶体(如云母)精细加工制备的。本文介绍了一种用有机薄膜作1/4波片的方法,即在实验室中对工厂生产的大面积均匀的有机薄膜进行测量,挑选所需波长的1/4波片。一、有机薄膜1/4波片原理很多高分子有机薄膜,如涤纶薄膜、聚丙烯薄膜等,在加热拉伸成膜的过程中,其线度     

Bi(Pb)-Sr-Ca-Cu-O(F)超导薄膜

本文介绍用电阻加热、单源混合分层蒸镀的方法制备掺 Pb 的 Bi-Sr-Ca-Cu-O(F)薄膜.我们用钼舟作加热源,用称量法控制膜的组份,采用金属 Bi、Pb、Cu 以及晶体 SrF_2和CaF_2 作原材料,把它们混合放入钼舟内加热蒸发.衬底为单晶 MgO(100).在热处理过程中通入湿氧和干氧,烧结温度850℃,获得了起始转变温度116K,零电阻温度103K 的超导薄膜.     

温度条件对反应电子束蒸发制备TiO2薄膜结构和性能的影响

研究基片温度(120～300 ℃)和热处理温度(400℃)对电子束蒸发TiO₂薄膜的结构和光学性能的影响.XRD分析表明,在120 ℃, 200 ℃和300 ℃的普通玻璃基片上采用电子枪加热蒸发制备的TiO₂薄膜具有非晶态结构,沉积态薄膜经过400 ℃保温1 h的热处理后得到的相为具有(004)取向的锐钛矿相,晶粒大小在3.6～8.1 nm之间.透射谱分析表明,薄膜的折射率随着基片温度的升高而增加;热处理后,薄膜的折射率也相应提高,其原因来自于薄膜的晶化.     

光转换有机白光发光二极管发光性能研究

研究一种有机白光发光材料,采用热熔法制备出有机薄膜(核黄素、蒽酮衍生物和线性低密度聚乙烯)。研究结果表明：核黄素、蒽酮衍生物和线性低密度聚乙烯的配比和制膜的加热时间对有机薄膜的发光光谱具有一定影响;得到了从绿光到红光的宽带光谱;用此薄膜封装成白光发光二极管的性能良好。     

Sn1-x(In1-yCuy)xO薄膜的合成

利用真空反应蒸发技术,在氧分压约为8.5×10-2Pa、衬底温度为400℃条件下蒸发高纯度的铟、锡和铜,在玻璃衬底上制备出Sn1-x(In1-yCuy)xO薄膜.研究了蒸发源材料质量比不同的样品的薄膜结构、透过率、薄膜的方块电阻和电阻率与温度的关系.实验结果表明,Sn1-x(In1-yCuy)xO透明导电薄膜具有优良的光电特性,而且制备出的Sn1-x(In1-yCuy)xO薄膜中In的含量大大减少,可以成为ITO薄膜的潜在替代材料.     

Sr-F共掺杂的SnO2基透明导电薄膜

利用离子源辅助的电子束热蒸发技术研制了高性能的Sr-F共掺杂SnO2( SFTO)基透明导电薄膜。所制备的SFTO薄膜具有良好的导电性和透过率,电阻率低于3.9×10-3Ω·cm,380~2500 nm波段的平均透过率大于85%,功函数约为5.10 eV。 SFTO透明导电薄膜为非晶态薄膜,具有较好的表面平整度( Rq <1.5 nm)。与工业上F掺杂SnO2薄膜的衬底温度(>450℃)相比,本文所用的衬底温度仅为300℃,有望直接将SnO2基透明导电非晶薄膜制备到柔性的塑料( PI、PAR或PCO)衬底上以获得性能良好的柔性电极。     

Influence of microscopic parameters of chiral molecules on the first-order hyperpolarizability

One-electron model is chosen to analyze the second harmonic response of an organic inclusion complex - urea l-malic acid (ULMA). ULMA has broad transparent region and large nonlinear optical coefficient and damage threshold. Based on the ULMA crystal structure, the model parameters are determined using the unit cell parameters. Numerical results show that the contribution of electric-field to the first-order hyperpolarizability β is larger than that of magnetic-field but the contribution of magnetic-field is important and cannot be neglected. Modeling parameters pitch ξ and radius ρ are found to be involved in the position of peak of β. The peak position of β undergoes red-shift with increasing of ρ and blue-shift with the increasing of ξ. It suggests that the expected nonlinear optical response of a chiral molecule can be obtained through molecular modification to adjust ξ and ρ. Therefore, a chiral molecule may be a favorable host to afford organic inclusion complex with superb nonlinear optical properties.     

旋涂法和热蒸发制备紫外CCD用晕苯薄膜的性能对比

晕苯是一种用于真空紫外光致发光重要的下转换材料。本文研究旋涂法和热蒸发法制备紫外CCD用晕苯薄膜的工艺方法,并对所制备的两种薄膜的性能进行了表征和对比。测试结果表明：旋涂方式成膜工艺简单,材料利用率较高,并且保持了荧光材料本身固有的晶体结构,但是膜面粗糙度较大;热蒸发方式成膜后紫外吸收较强,荧光发射强度相对较高,成膜后膜面粗糙度较小;热蒸发工艺在加热过程中改变了晕苯的晶体结构并形成了新的结晶态;相比于旋涂法,热蒸发的整个制备工艺相对复杂,并且生产成本较高。此外,该对比性研究工作为实现不同要求(如荧光发射强度、表面粗糙度、生产成本等)的荧光下转换薄膜的制备提供了理论指导。     

Experimental research of laser-induced damage of the monolayer ZrO2 PVD and sol–gel films

Monolayer zirconia physical vapor deposition (PVD) and sol–gel films on K9 glass substrates were prepared by electron beam evaporation and spin coating methods, respectively. The laser-induced damage threshold (LIDT) of each film was measured. Properties of the films were analyzed using Stanford photo-thermal solutions (SPTS), ellipsometry, atomic force microscopy (AFM) and optical microscopy to study the damage mechanism of films under laser irradiation. The experimental results showed that, compared with the monolayer zirconia sol–gel film, the monolayer zirconia PVD film had larger absorption and smaller porous ratio, and that it had smaller LIDT. The different damage morphologies of films were influenced by their different absorption and microstructure characteristics. The zirconia sol–gel film is more suitable for applications involving high-power lasers.     

Synthesis,growth and characterization of non-linear optical material: l-Tryptophan p-nitrophenol (LTPNP) single crystal

A new nonlinear optical organic crystal l-tryptophan p-nitrophenol (LTPNP) of dimension 19 mm × 2 mm × 1.5 mm has been grown from an aqueous solution for the first time by slow evaporation technique at ambient temperature. The crystal structure of LTPNP was confirmed by single crystal X-ray diffraction. LTPNP crystallizes in non-centrosymmetric monoclinic system with space group P₂₁. The recorded FTIR spectrum confirms the presence of various functional groups in the grown crystal and confirms the formation of LTPNP. Thermal stability and melting temperature of the LTPNP crystal were identified from TG/DTA analysis. The optical absorption study confirms the suitability of the crystal for device applications. LTPNP exhibits SHG efficiency over 1.7 orders of magnitude higher than that of urea and 4 orders of magnitude higher than that of KDP.     

溶液浇铸法制备氘代聚乙烯薄膜

 采用改进的溶液浇铸法,用氘代聚乙烯为原料,制备了厚度为100, 200, 400 μm的氘代聚乙烯薄膜。研究了溶液温度、干燥温度、真空加热温度及时间等因素对成膜性、薄膜均匀性和透明性的影响,确定了最佳工艺条件：溶液温度120～130 ℃,干燥温度80～100 ℃,加热温度120 ℃,加热时间1 h。3维视频显微镜和原子力显微镜表征结果表明:制备的薄膜透明性较好,厚度较均匀;薄膜表面起伏较小。     

Effect of urea and thiourea on nonlinear optical hippuric acid crystals

Pure, urea and thiourea doped hippuric acid (HA) single crystals have been grown in acetone using slow evaporation technique at a constant temperature, with the vision to improve the properties of the crystals. The crystal systems and the unit cell parameters of the grown crystals were identified from single crystal X-ray diffraction. The crystalline nature of the grown crystals was confirmed by powder X-ray diffraction and the diffraction peaks were indexed. The variations in composition due to the addition of dopants were identified by CHNS analysis. FT-IR studies reveal the presence of different vibrational bands. The optical characteristics were assessed by UV–vis analysis and it indicates the transmission in the visible region. TGA and DSC studies indicate the thermal behavior of pure and doped crystals. The Second Harmonic Generation (SHG) has been tested using Kurtz Powder Technique for the pure and doped crystals. It is found that the thiourea doped hippuric acid crystals have SHG efficiency of 2.08 times higher than that of potassium dihydrogen phosphate (KDP) single crystal. The dielectric studies were carried out, and the variations of dielectric constant and dielectric loss with temperature have been studied.     

Synthesis,spectral, thermal and optical characterization of benzyltributylammonium trichlorobarium(II) monohydrate crystal

A new nonlinear optical semiorganic crystal, benzyltributylammonium trichlorobarium(II) monohydrate was grown by slow evaporation solution growth method at ambient temperature. The powder X-ray diffraction pattern of the crystal confirms its crystallinity. The absorption spectrum of the material shows a peak at 265 nm and no absorption observed in the entire visible region indicates that the compound can be used as a nonlinear optical material. The optical transmittance spectrum of the grown crystal shows a lower cut-off wavelength at 235 nm with transparency of 88%. Thermal stability of the crystal was studied by thermogravimetry-differential thermogravimetry and differential thermal analyses (TG-DTG and DTA). The differential scanning calorimetry (DSC) analysis shows thermal anomalies in the heating and cooling cycles that indicates the occurrence of a first order phase transition. The various characteristics absorption chemical bands and BaCl₃⁻ vibration were assigned through fourier transform infrared (FTIR) spectral analysis. The second harmonic generation efficiency (SHG) of the grown crystal was analyzed by Kurtz–Perry powder technique using Nd:YAG laser. The dielectric constant and dielectric loss of the compound decrease with increase in frequency.     

A Critical Review on Physical Vapor Deposition Coatings Applied on Different Engine Components

Friction and wear in different engine components have crucial effects on the engine performance, combustion efficiency, oil consumption and lifetime of the internal combustion (IC) engine. Under certain loads, speeds, and temperatures, the metallic components of the IC engine, especially the piston and valve system suffer from a higher friction. Thin film coating is one of the novel techniques to reduce the frictional forces and improve the mechanical properties of engine components. Due to some versatile tribological properties, increasing attention has been paid to the physical vapor deposition (PVD) technology in the recent decade to deposit thin film coating on engine components. This article presents a comprehensive literature review on thin film coatings for IC engine components deposited by PVD technique. Issues related to tribological properties (wear and coefficient of friction) and mechanical properties (hardness and roughness) are also highlighted. Scientific improvements are presented in the light of literature. It is revealed that PVD coating is significantly effective on wear resistance, scuffling resistance, surface roughness, and friction of the components in IC engine. Laboratory test and data from actual service so far suggest that the plasma-activated electron beam evaporation coating is perhaps one of the best choices for smooth surface finishing with improved mechanical and tribological properties. However, there are still some problems in its practical usage. This compressive review paper presents the major shortcomings of PVD coatings on IC engine components and the possible solutions if any. Finally, a number of issues have been reported which need to be encountered for further studies.     

Generation of 532 nm laser radiation and phase matching properties of organic nonlinear optical material

Organic nonlinear optical single crystal of l-asparagine-l-tartaric acid (LAsT) was grown by slow evaporation technique at room temperature. The grown crystal was confirmed by single crystal X-ray diffraction and FT-IR studies. The direct band gap energy was found to be 5.4 eV. The SHG efficiency of the sample is 3 times higher than that of KDP crystal. The laser damage threshold of the grown crystal was 5.7 GW/cm². The grown crystal was thermally stable up to 141 °C. Low dielectric constant at higher frequency was found by dielectric measurements. The activation energy was calculated from Arrhenius relation and it was found to be 0.088 eV. Negative photoconducting nature was obtained by photoconductivity measurements.