Superhydrophobic antireflective coating with high transmittance

The aim of this study is to fabricate a superhydrophobic antireflective (AR) coating that can be deposited on the covering of a solar cell system. First, AR coatings were synthesized on glass substrates with an average transmittance over 96% by layer-by-layer deposition of polyelectrolyte. Superhydrophobic sol gel was prepared by hydrolyzing tetraethoxysilane and then reacting it with hexamethyldisilazane. The sol gel, aged at 20°C for 96 h, was used to spin-coat a superhydrophobic film with a water contact angle of 163° and a transmittance of ~91%. The superhydrophobic sol gel was spin-coated on the top of an AR coating to form a superhydrophobic AR coating on a glass substrate. The average transmittance, advancing contact angle, and contact angle hysteresis of the superhydrophobic AR coating, which was spin-coated from sol gel aged for 96 h or 168 h, were 94.5 ± 0.7%, 154.0° ± 1.5°, and 15.4° ± 0.3° or 96.4 ± 0.2%, 158.4° ± 4.4°, and 1.8° ± 0.3°, respectively. Strategies for obtaining a superhydrophobic AR coating are discussed herein.     

Suppression of resist contamination during photolithography on carbon nanomaterials by a sacrificial layer

To suppress photoresist residues on carbon nanotubes (CNTs) resulting from photolithography, CNTs are covered by a sacrificial layer during photolithography. Using aluminum oxide (Al₂O₃) deposited by low temperature atomic layer deposition as the sacrificial layer, the fabricated suspended CNT field-effect transistors exhibit low on-state resistances as low as 91 kΩ and low gate hysteresis of 0.5 V in ambient air. The effectiveness of this technique in suppressing residues on CNTs was affirmed by atomic force microscopy, scanning electron microcopy, and micro Raman spectroscopy. The etchants of Al₂O₃, hydrofluoric acid and phosphoric acid, were found not to cause defects in CNTs while removing the sacrificial Al₂O₃ layer. With the protection of the Al₂O₃ layer, oxygen plasma ashing can be performed without causing further defects in CNTs, and the minimum thickness was determined to be between 9 nm and 17 nm. This simple and effective approach can be easily implemented in different resist-based lithography processes to fabricate carbon nano-devices that are free of resist residues.     

Polymer nanoparticle-based porous antireflective coating on flexible plastic substrate

Increased using of plastic optical elements has generated a need for applying antireflection coatings onto plastic substrates. In this paper we reported a facile method to preparing porous thin films on plastic substrates by spin-casting poly (methyl methacrylate) (PMMA)/polystyrene (PS) mixed latices, followed by selectively removing PS particles. The refractive index of the porous coating is directly related to its porosity which could be controlled by varying mixing fraction of the sacrificial PS particles. The obtained porous thin films exhibited excellent anti-reflective (AR) performance over visible range with minimum reflection of 0.02%. The powerful control on refractive index and the versatility of this method makes it practicable to prepare antireflective coating on various plastic substrates with optimal performance.     

Diamond like carbon used as antireflective coating on crystalline silicon solar cells

Amorphous carbon with different structures was used as antireflective coating on crystalline silicon solar cells. Polymeric-like carbon (PLC) and diamond-like carbon (DLC) were deposited by the PECVD technique on the anode and cathode electrode, respectively. Tetrahedral-like carbon (ta-C) was deposited by the filtered cathodic vacuum arc (FCVA). An increase in the short circuit current comparable to that obtained by conventional antireflective coating (SnO₂) was obtained using PLC antireflective coating. The effect on the short circuit current of the other structures (DLC and ta-C) is reduced mainly due to the band gap and/or a mismatch on the index of refraction of the film and the crystalline silicon substrate.     

Ultradense and planarized antireflective vertical silicon nanowire array using a bottom-up technique

The production and characterization of ultradense, planarized, and organized silicon nanowire arrays with good crystalline and optical properties are reported. First, alumina templates are used to grow silicon nanowires whose height, diameter, and density are easily controlled by adjusting the structural parameters of the template. Then, post-processing using standard microelectronic techniques enables the production of high-density silicon nanowire matrices featuring a remarkably flat overall surface. Different geometries are then possible for various applications. Structural analysis using synchrotron X-ray diffraction reveals the good crystallinity of the nanowires and their long-range periodicity resulting from their high-density organization. Transmission electron microscopy also shows that the nanowires can grow on nonpreferential substrate, enabling the use of this technique with universal substrates. The good geometry control of the array also results in a strong optical absorption which is interesting for their use in nanowire-based optical sensors or similar devices.     

一种新型防水涂料的制备

实验采用氢化C5石油树脂作为成膜物质制备新型防水涂料.通过对乳化剂的筛选和物料配比的考查,确定了制备乳液的最佳条件,并通过对其它助剂加入量的考察,确定了防水涂料的最佳配方.实验结果表明,当乳化剂选用复配型乳化剂,m(氢化C5石油树脂):m(石蜡)=2:1时,制备的乳液效果最好;当m(氢化C5石油树脂乳液):m(涂料)=...     

DISGO——一种性能优异的新型涂层

DISGO涂层具有优异的耐候性、耐蚀性和环境友好的表面特性 ,其可望在特殊性能涂层领域得到广泛的应用。简述这一涂层的防蚀机理、涂层结构及涂层特性。     

Efficiency enhancement of non-selenized Cu(In,Ga)Se2 solar cells employing scalable low-cost antireflective coating

In this study, a non-selenized CuInGaSe₂ (CIGS) solar device with textured zinc oxide (ZnO) antireflection coatings was studied. The ZnO nanostructure was fabricated by a low-temperature aqueous solution deposition method. With controlling the morphology of the solution-grown tapered ZnO nanorod coatings, the average reflectance of the CIGS solar device decreased from 8.6% to 2.1%, and the energy conversion efficiency increased from 9.1% to 11.1%. The performance improvement in the CuInGaSe₂ thin-film solar cell was well explained due to the gradual increase of the refractive index between air and the top electrode of solar cell device by the insertion of the ZnO nanostructure. The results demonstrate a potential application of the ZnO nanostructure array for efficient solar device technology.     

A novel resist technique based on secondary amines for the printing of cotton with reactive dyes

In an earlier paper we have described sulphite‐based resist printing using ink‐jet procedures. This paper describes an alternative approach to sulphite inactivation of vinylsulphone dyes by using secondary amines to inactivate fluoro‐s‐triazine dyes while maintaining the reactivity of the vinylsulphone dyes. Monofluoro‐s‐triazine reactive dyes are padded onto cotton fabrics and then deactivated by ink‐jet printing with a suitable secondary amine formulation to produce a white image on a solid ground colour after appropriate fixation and soap‐off procedures have been undertaken. A coloured image can be achieved by overprinting the resist‐printed areas with a coloured ink formulation containing a β‐sulphatoethylsulphone‐type reactive dye; such dyes form a β‐bis‐alkylaminoethylsulphone dye via reaction with the secondary amine. This latter dye ‘unblocks’ during a mildly acidic steaming process to form the reactive vinylsulphone dye, and so, unlike the monofluoro‐s‐triazine dye, is not deactivated towards subsequent covalent reaction with the cotton substrate.     

Ion beam assisted electron beam vacuum deposition of antireflective SiO2 coating on MgAl2O4 spinel

In this paper, the electron beam vacuum coating method was used to coat a SiO₂ film on an MgAl₂O₄ spinel substrate. The thickness of the coating was aimed to be 925 nm based on the physics of the antireflection coatings. Atomic force microscope images revealed that the coated silica was 880 nm thick, which is close to the aimed theoretical thickness and had 2.11 nm roughness. It could enhance the transparency of the spinel substrate by being coated on it. The infrared transmittance of the sample coated with SiO₂ film in the range of 3700 nm-4800 nm was measured by a Fourier transform infrared spectrometer and reached 92.5% to 78.5%, which was about 2%–4% higher than that of MgAl₂O₄ spinel. In addition, it was discovered that the bonding force between the coating and the substrate is determined to be about 200 MPa. The results of this study can be used for further precise design and production of antireflection coatings on the transparent materials that need more transparency.     

Poly(4-chlorostyrene), a new high contrast negative E-beam resist

PCS(poly-4-chlorostyrene) has previously been evaluated as a negative e-beam resist, but although the sensitivity was good [2 to 5μC/square centimeter (cm²)], the contrast (γ) was poor (1.1 to 1.5). Recent experiments have shown that contrast is not only a function of molecular weight distribution (MWD), but can also be affected by polymerization conditios. Among these are: branching, head to head linkages, and oxygen in backbone. PCS was prepared via thermal free radical solution polymerization, and then fractionated by differential solvation techniques. Reactions occurring during polymerization and crosslink formation on irradiation will be discussed. For molecular weights of 700 and 300K respectively (same MWD), the sensitivity was 2 and 5μC/cm², while the contrast (γ) was 3.5 for both. This is the highest reported contrast for a polymeric negative resist. The resist can then be UV hardened after development, and will not flow at 200°C. The RIE etch rate is ～1/2 that of PMMA in various plasmas.     

铝阳极氧化膜多色彩电解着色工艺

简述了多色彩电解着色工艺的发展和特点,介绍了2种达到多色化显色的方法:阳极氧化膜底部扩孔处理和调整阳极氧化膜阻挡层。给出了扩孔处理过程中阳极氧化膜横断面的显微结构变化示意图,并给出了“阻挡层调整”实现多色化的工艺参数。描述了多色化阳极氧化膜的性能,并对比了电泳涂漆前后多色彩电解着色样品的颜色。     

Polymers of α-substituted benzyl methacrylates as a new type of electron-beam resist

Summary Polymer of α-substituted benzyl methacrylate was found to be used as a new type of positive electron-beam resist, which forms methacrylic acid units in the polymer chain on the exposure to electron-beam and can be developed using alkaline solution as a developer. The sensitivity was dependent on the bulkiness of the ester group and the number of ?-hydrogen atoms in the ester group. The sensitivity and γ-value of atactic poly(α, α-dimethylbenzyl methacrylate) were improved by a factor of more than three over poly (methyl methacrylate).     

一种新型涂覆型高分子抗静电剂的制备研究

采用自制季铵盐、甲基丙烯酸甲酯、丙烯酸丁酯、无水乙醇等为原料,通过无规共聚反应制备了一种新型的涂覆高分子抗静电剂.探讨了自制季铵盐的含量对该抗静电剂的表面电阻及耐水性的影响,以及甲基丙烯酸甲酯、丙烯酸丁酯的配比对产品附着力的影响.     

新型水溶性防锈涂料的研制

水溶性涂料由于具有成本低、环境污染少及防火等优点而得到广泛应用。为提高水溶性防锈涂料的储存稳定性、消除涂料吸附失干及不易消泡等缺点，以亚麻油、顺丁烯二酸酐和改性酚醛树脂加合而成的水性树脂为基料，在一定比例的防锈颜料、填料混合配制出一种新型水溶性防锈涂料。研究了改性树脂、顺丁烯二酸酐、防锈颜料、反应温度与时间对涂膜各项性能的影响，并对涂膜的各项性能进行了测试。结果表明，所得涂膜附着力强、防锈性能好，储存稳定性及消泡等性能明显改善。     

Characteristics of nFOG,an aerosol-based wet thin film coating technique

An atmospheric pressure aerosol-based wet thin film coating technique called the nFOG is characterized and applied in polymer film coatings. In the nFOG, a fog of droplets is formed by two air-assist atomizers oriented toward each other inside a deposition chamber. The droplets settle gravitationally and deposit on a substrate, forming a wet film. In this study, the continuous deposition mode of the nFOG is explored. We determined the size distribution of water droplets inside the chamber in a wide side range of 0.1–100 µm and on the substrate using aerosol measurement instruments and optical microscopy, respectively. The droplet size distribution was found to be bimodal with droplets of approximately 30–50 µm contributing the most to the mass of the formed wet film. The complementary measurement methods allow us to estimate the role of different droplet deposition mechanisms. The obtained results suggest that the deposition velocity of the droplets is lower than the calculated terminal settling velocity, likely due to the flow fields inside the chamber. Furthermore, the mass flux of the droplets onto the substrate is determined to be in the order of 1 g/m³s, corresponding to a wet film growth rate of 1 µm/s. Finally, the nFOG technique is demonstrated by preparing polymer films with thicknesses in the range of approximately 0.1–20 µm.     

A polymer complex as a new type of electron beam resist for dry development

Polymer complex of poly (4-vinylpyrldine) and malonic acid was investigated as a new type of electron beam (EB) resist for dry development, as malonic acid was decomposed by EB irradiation. It was found that the polymer complex could be developed with O₂ plasma etching and that the positive resist patterns with high resolution could be obtained. The mechanism for this lithography process was studied by means of IR and ESCA spectra.     

新型固相微萃取涂层的制备与应用

实验合成了苯乙烯-甲基丙烯酸-醋酸乙烯酯聚合物,作为固相微萃取的涂层,考察了聚合物的热稳定性,自制SPME装置。采用HS—SPME—GC方法测定了水中苯、甲苯、二甲苯。对该方法的线性、重复性、最小检出限、回收率等进行了试验测定,结果令人满意。     

运用回转式煅烧技术烧制新型粉体材料应用技术探讨

近年来，随着国内新型材料及粉体产业的高速发展，新型粉体材料的深加工在各行业中都有了更多更高的要求。在原有的粉体静态煅烧技术上开发新型的动态加热煅烧技术及装备，对粉体材料的煅烧品质、产品反应均匀性、产品的煅烧周期、能耗等，都有着现实而深远的意义。回转式粉体加热技术就是在此基础上推出而运用于目前新型粉体材料煅烧的一项应用技术，其节能显著、煅烧均匀等特点已被国内诸多企业认可和接受。