A Novel Approach to Synthesizing Porous ZnO Films: Inorganic Chelating Sol-Gel Method

Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface morphology,porous and optical properties of the deposited films are investigated.X-ray diffraction pattern analysis shows that crystal structure of the ZnO films is hexagonal wurtzite.Scanning electron microscopy (SEM) shows that the ZnO film is porous.The curve of pore size distribution has two peak values at about 2.02nm and 4.97nm and BET surface area of the ZnO film is 27.57m2/g.In addition,the transmittance spectrum gives a high transmittance of 85% in the visible region and optical bandgap of the ZnO film (fired at 500℃) is 3.25eV.

Organic-inorganic Hybrids Towards the Preparation of Nanoporous Composite Thin Films for Microelectronic Application

Silicon containing materials have traditionally been used in microelectronic fabrication. Semiconductor devices often have one or more arrays of patterned interconnect levels that serve to electrically couple the individual circuit elements forming an integrated circuit. These interconnect levels are typically separated by an insulating or dielectric film. Previously, a silicon oxide film was the most commonly used material for such dielectric films having dielectric constants( k ) near 4 0. However, as the feature size is continuously scaling down, the relatively high k of such silicon oxide films became inadequate to provide efficient electrical insulation. As such, there has been an increasing market demand for materials with even lower dielectric constant for Interlayer Dielectric(ILD) applications, yet retaining thermal and mechanical integrity. We wish to report here our investigations on the preparation of ultra low k ILD materials using a sacrificial approach whereby organic groups are burnt out to generate low k porous ORMOSIL films. We have been able to prepare a variety of organically modified silicone resins leading to highly microporous thin films, exhibiting ultra low k from 1 80 to 2 87, and good to high modulus, 1 5 to 5 5 GPa. Structure property influences on porosity, dielectric constant and modulus will be discussed.

Controlled Microstructure and Photochromism of Inorganic-organic Thin Films by Ultrasound

A series of inorganic-organic thin films based on uniformly dispersed nanoparticles of polyoxometalates （POM）entrapped in polyacrylamide （PAM） matrix were prepared by ultrasonic method with different irradiation time.The microstructure, photochromic behavior and mechanism of the films were studied by transmission electron microscopy （TEM）, ultraviolet-visible spectra （UV-VIS） and Fourier transform-infrared spectroscopy （FT-IR）.The microstructure and photochromic properties of the hybrid thin films could be controlled by ultrasound.TEM image revealed that the average size of phosphotungstic acid （PWA） nanoparticles decreased from 20 to 10 nm with the ultrasound irradiation time from 30 to 60 min. After irradiated with ultraviolet light,the transparent films changed from colorless to blue and showed reversible photochromism. The hybrid film, with ultrasound irradiation for 60 min had higher photochromic efficiency and faster bleaching reaction than the one with ultrasound irradiation for 30 min. FT-IR spectra showed that the Keggin geometry of heteropolyoxometalate was still preserved inside the composites, and the interactions between polyanions and polymer matrix increased as the ultrasound time prolonged. It is suggested that the mechanism of the different photochromic properties for the inorganic-organic thin films is the variation of the microstructure and interfacial interactions induced by ultrasound.

Preparation and Optical Patterning of Organic-Inorganic Hybrid Color-Filter Films Using Latent Pigments by Utilizing Photo-Acid-Generator and Microwave Irradiation

Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigment by using photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin film modified with methoxysilane containing PAG was formed on a glass substrate and irradiated with ultraviolet rays to promote sol-gel reaction by catalytic action of acid which was generated from PAG. And then the film was hardened with microwave irradiation, yielding organic-inorganic hybrid polymer film having hardness, highly transparency and strong adhesion with a glass substrate. Since this reaction only occurred in the optically (UV) irradiated regions, by exploiting the difference between the adhesivenesses of these regions photo-irradiated through photomask with a glass substrate, it was possible to form a patterned film with pitch of 100 to 50 μm by a simple lift-off method. A pigment-containing film using latent pigments (with subtractive three primary colors of coloring materials) and a patterned film were prepared, and it was possible to make these films multi-colored by varying the mixing ratio of the pigments. This multi-colored film-preparation method is effective for simply and efficiently forming a color-filter film by applying optical and microwave irradiation.

The Production of Organic-Inorganic Compound Film-Coated Urea and the Characteristics of Its Nutrient Release

The effect of different concentrations of natural macromolecular compound on the characteristics of nutrient release in the membrane materials of organic-inorganic compound film-coated urea was discussed, and the optimal concentrations for better nutrient release was proposed. The characteristics of nutrient release of film-coated urea were evaluated by soil column leaching experiment. Organic-inorganic compound film-coated urea showed good characteristics of nutrient release, which could be well simulated by Logistic curve. The two parameters in this curve, a and r, can be used to present nutrient release of film-coated urea, and followed the order of B 〉 C 〉 A and C 〈 B 〈 A, respectively, indicating that the release was stronger with the increasing concentration of natural macromolecular compound in the membrane, which implied better controllability of nutrient release. The concentration of 5% of natural macromolecular compound showed better characteristic of nutrient release and can be utilized as a membrane material combined with inorganic mineral powders to develop film-coated slow-release fertilizer.

Thin Film Encapsulation at Low Temperature Using Combination of Inorganic Dyad Layers and Spray Coated Organic Layer

Organic devices have many advantages such as low material consumption and low energy requirements, but they have serious issues regarding long term stability. Hence we need to develop a barrier film which solves this problem. Initially, the organic devices were fabricated on glass and were encapsulated using glass and epoxy (as sealant). Gradually there was a need to shift on to flexible substrates which required encapsulation to be flexible as well. Therefore, the motivation of the work is to develop thin film encapsulation that can be made flexible. The low temperature PECVD grown films of SiOx and SiNxwere used as the barrier film. Alternate inorganic layers (2-dyads) provided barrier of ~10-2 g/m2 day and increasing the number of dyads to five improved the water vapor transmission rate (WVTR) only by one order of magnitude. However, introducing organic layers in this structure resulted in WVTR value of order 10-5 g/m2 day. The organic layers were deposited by spray technique.

Rapid communication Preparation of TiO_2 nanometer thin films with high photocatalytic activity by reverse micellar method

Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-rayphotoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalyticdecoloration of methyl orange aqueous solution. The results showed that the TiO_2 thin filmsprepared by reverse micellar method (designated as RM-TiO_2 films) showed higher photocatalyticactivity than those by sol-gel method (designated as SG-TiO_2 films). This is attributed to the factthat the former is composed of smaller monodispersed spherical particles with a size of about 15 nmand possesses higher surface areas.

Effect of growth time on morphology and photovoltaic properties of ZnO nanowire array films

Single-crystalline ZnO nanowire arrays with different aspect ratios and nanowire densities were prepared by the hydrothermal growing method using polyethyleneimine （PEI） as a surfactant. PEI can only hinder the lateral growth of the ZnO nanowires, which is observed by high resolution transmission electron microscopy （HRTEM） analysis. Dye-sensitized solar cells were assembled by the ZnO nanowire arrays with different thicknesses, which can be controlled by the growing time and characterized using photocurrent-voltage measurements. Their photocurrent densities and energy allover conversion efficiencies increased with increasing ZnO nanowire lengths. Short-circuit current density of 4.31 mA.cm-2 and allover energy conversion efficiency of 0.87% were achieved with 12.9-μm-long ZnO nanowire arrays.

Effects of precursor solution concentration on the properties and morphology of YBCO films deposited by TFA-MOD method

Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and Jc excess 2 MA/cm^2 at 77 K in zero field. XRD θ-2θscans show all the films have c-axis normal orientation. The FWHM （full width at half-maximum intensity） values of X-ray ω-scans of （005） reflection are 0.379°, 0.283°, and 0.543° for the YBCO thin films deposited with precursor solution concentrations of 1.52, 1.0, and 0.75 mol/L, respectively. With the concentration of the precursors decreasing, the thickness of the films decreases linearly. SEM micrographs show that porosities in the films become bigger with the precursor solution concentration decreasing. The big porosities in the film with the lowest concentration precursor deteriorate the superconducting property and make it have a wider superconducting transition and a lower Jc.

LiMn_2O_4 thin films derived by rapid thermal annealing and their performance as cathode materials for Li ion battery

The LiMn2O4 thin film as a cathode material was prepared through solution deposition followed by rapid thermal annealing （RTA）. The phase identification and the study of surface morphology were carried out by X-my diffraction and scanning electron microscopy. Electrochemical properties were examined by cyclic voltammetry, galvanostatic charge-discharge experiments, and electrochemical impedance spectroscopy. The results show that the film prepared by this method is homogeneous, dense, and crack-free. The thin film has a capacity of 38 μtAh/（cm^2·μm） with the capacity loss of 0.037% per cycle after being cycled for 100 times. The average diffusion coefficient for lithium ions in the RTA-derived LiMn2O4 thin film is 1×10 ^-10 cm^2·s^-1.

Preparation of CuInSe_2 thin films by paste coating

Precursor pastes were obtained by milling Cu-In alloys and Se powders. CulnSe2 thin films were successfully prepared by precursor layers, which were coated using these pastes, and were annealed in a H2 atmosphere. The pastes were tested by laser particle diameter analyzer, simultaneous thermogravimetric and differential thermal analysis instruments （TG-DTA）, and X-ray diffractometry （XRD）. Selenized films were characterized by XRD, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises. All the CuInSe2 thin films, which were annealed at various temperatures, exhibit the preferred orientation along the （112） plane. The compression of precursor layers before selenization step is one of the most essential factors for the preparation of perfect CuInSe2 thin films.

Studies on the Structure of Gel during Preparing ZnO Thin Films by Sol-gel Method

Transparent thin films of ZnO have been prepared on ordinary glass substrates by the inorganic sol-gel method using citric acid as chelating agent and zinc nitrate as the starting material. A novel structure on zinc citrate complex was put forward by using DTA-TG and FT-IR absorbanee spectrum of citrate gels. Phase formation, morphology and optical properties of ZnO films are investigated by XRD, AFM and UV-vis transmittance spectra. The experimental results show that ZnO thin films derived from zinc citrate sol-gel method showed a （002） oriented hexagonal wurtzite structure, good crystalline property, a uniform range of grain size （40 nm）, smooth surface of films, band gap of 3.28 eV and optical transmittances ratio over 90% in the visible range.

Flexible inorganic piezoelectric functional films and their applications

Piezoelectric materials play an increasingly important role in energy harvesters,sensors,and actuators.Flexible and thin piezoelectric films have been demonstrated to provide advanced functionalities and improved performances.However,the research on flexible inorganic piezoelectric thin films has rarely been systematically summarized.Here,we summarize the recent advances in the flexible inorganic piezoelectric thin films,focusing on their structural designs,fabrication techniques,and applications in various practical scenarios.Specifically,different fabrication techniques suitable for diverse inorganic piezoelectric nanostructures are reviewed,including sol-gel,hydrothermal,electrospinning,and other techniques,and the integration process with flexible substrates is further discussed.Biomedical and industrial applications of the flexible piezoelectric thin films are emphasized.Finally,some existing challenges and future perspectives are discussed.

Production and application of Baosteel inorganic-lubricant-coated galvannealed automobile steel sheet

The inorganic-lubricant-coated galvannealed automobile steel sheet is a new product that improves the press formability of automobile body panels.In this paper,the production process,physical and chemical properties,press formability,and corrosion resistance of this new automobile steel sheet were discussed.Test results show that this inorganic solid-lubricant galvannealed automobile steel sheet has good surface friction characteristics and press formability.This product also meets the automobile industry’s requirements for press formability,phosphate pro-perties,and corrosion resistance after coating.

用于柔性电子器件的有机/无机薄膜封装技术研究进展

有机/无机薄膜封装技术被广泛用于有机发光二极管(OLED)、量子点显示及有机光伏等领域,是一种新型的柔性封装技术。综述近年来有机/无机薄膜封装技术的发展趋势,首先概述了传统硬质盖板封装方式与薄膜封装方式的发展及其优缺点。其次,系统地总结了有机/无机薄膜的制备方法,如原子层沉积、等离子体化学气相沉积等,详细阐述了不同制备方法的原理及其应用。再次,讨论了薄膜的微观缺陷、内应力,以及材料界面工程对有机/无机薄膜封装性能的影响,分析总结了有机/无机封装薄膜制备的技术要点,如采用基底表面预处理、引入中性层、调节层间应力等方式获得优质的封装薄膜。最后,探究了有机/无机封装薄膜的内在阻隔机理,提出气体在有机/无机薄膜中的传输方式以努森扩散为主,并总结了提高薄膜封装的策略,即延长气体扩散路径、“主动”引入阻隔基团及薄膜表面改性。提出了未来薄膜封装技术面临的问题,拟为柔性电子器件封装技术的发展提供一定参考。

复合改性纤维基调湿材料吸放湿性能研究

以主要成分为植物纤维的纤维片材作为调湿材料的基材,利用无机盐的高吸湿性对纤维片材进行改性,以改善其调湿能力。为了减少无机盐的流失,采用高吸水性树脂和防水透气膜对纤维片材进行了复合。在恒温恒湿箱中对原材料和复合纤维片材进行了吸湿和放湿试验,并测试了复合纤维片材的盐流失性。结果表明,氯化钠可以提升纤维片材的吸放湿性能,但盐流失率较大;高吸水性树脂和防水透气膜的复合可有效减少纤维片材中无机盐的流失,其中采用高吸水性树脂复合纤维片材具有良好的调湿性能,且盐流失率较小。

无机薄膜组织结构及应力演化行为研究现状

物理气相沉积技术制备的无机薄膜,其组织结构及残余应力会在储存或服役环境中自发地产生演化,进而使薄膜性能发生变化,最终影响薄膜的长期服役稳定性。首先从物理气相沉积技术制备薄膜的组织结构特征入手,介绍了无机薄膜应力的产生,发现薄膜的残余应力主要受薄膜非平衡生长后的亚稳态、薄膜与基体之间的晶格错配以及热膨胀系数差异的影响。之后论述了无机薄膜在生长过程中应力的演化规律,这个规律主要受薄膜的制备工艺影响,包括沉积速率、沉积气压、沉积温度以及基体偏压等。随后,重点综述了非平衡生长后的亚稳态金属薄膜、陶瓷薄膜及金属/陶瓷复合薄膜的组织结构、残余应力在储存或服役环境中的演化,以及薄膜性能变化行为的研究进展。针对无机薄膜在自然时效及人工时效过程中,其组织结构演变与应力释放的关系进行了总结和讨论,发现原子扩散是自然时效及人工时效过程中薄膜产生变化的主要途径。最后,对无机薄膜组织结构及应力演化行为的研究方法进行了展望。

机器学习在化学气相沉积中的应用研究进展

化学气相沉积技术是一种近几十年发展起来的制备无机材料的化工技术。随着机器学习技术的发展,其在化学气相沉积领域也发挥着不小的作用。基于此,本文概述了化学气相沉积的原理与机器学习的发展历程,分析了机器学习在化学气相沉积中的典型应用,总结并分析了未来应用的发展趋势。

储能电容无机电介质薄膜研究进展

无机电介质薄膜相对有机电介质材料具有更高的工作温度范围,相对无机块体陶瓷材料又有更高的击穿场强和储能密度,因而近年来受到研究者的关注.从无机电介质薄膜材料的5种类型:顺电薄膜、铁电薄膜、弛豫铁电薄膜、反铁电薄膜和线性电介质薄膜,分类综述了过去10余年这个领域优化其储能性能的手段与思路,从不同尺度归纳无机电介质薄膜的储能改性策略,最后展望发展趋势,如应用场景的挖掘、能量效率与能量密度的平衡和多尺度改性等.

不同助剂对无机内墙涂料稳定性及成膜性的影响

[目的]以硅酸盐溶液作为主要成膜剂的无机内墙涂料存在贮存稳定性与成膜性能差的技术缺陷。[方法]以硅酸钾溶液和苯丙乳液作为主要成膜物,采用共混法制备无机内墙涂料,研究了不同分散剂、增稠剂、稳定剂和消泡剂对涂料黏度、防流挂性和涂层表观的影响。[结果]确定了制备无机内墙涂料的最佳工艺参数为:六偏磷酸钠(分散剂)0.4%(质量分数,下同),羟丙基甲基纤维素0.1%,黄原胶0.1%,聚氨酯类增稠剂0.5%~1.0%,季铵盐类稳定剂0.5%,矿物油类消泡剂0.5%。[结论]该涂料具有较好的贮存稳定性及成膜性能,能够满足相关国家标准的要求。