Tetraboryl derivatives of porphyrins in the synthesis of novel fluorenes

A new strategy for the synthesis of fluorene-containing porphyrins by Suzuki–Miyaura reaction using a tetraboryl porphyrin derivative and a fluorene derivative of 4-bromoaniline has been proposed. A number of consecutive chemical transformations of the prepared porphyrin have led to formation of a polyphenol derivative of the above compound. Positive photoresists for lithography with exposing radiation wavelength of 13.5 nm have been developed on the basis of a similar polyphenol, which provided preparation of topological structures with a resolution of 22–16 nm.     

光刻技术:发展路径及未来趋势

光刻技术在半导体器件大规模生产中发挥重要作用.今天,多数先进半导体生产都已经应用ArF准分子激光浸润光刻技术.双重图像曝光和侧壁图像转移技术使ArF准分子激光浸润光刻技术延伸到32纳米半节距(HP)器件的制造成为可能.为了制造更小尺寸的器件,必须开发新的制造工艺.极端紫外线光刻是制造22纳米半节距甚至更小尺寸半导体器件的先进下一代光刻技术解决方案.另外,其他技术解决方案,如纳米压印光刻技术和无掩模直描光刻技术等也被考虑用于制造更小节点尺寸的器件,但是目前这些方案仅仅处在研发阶段,而且在现阶段就已经呈现出在大规模生产中的诸多困难.本文从材料的角度对光刻技术进行一个整体描述,并对光刻技术未来趋势进行讨论.     

Excitation-wavelength-dependent fluorescent organohydrogel for dynamic information anti-counterfeiting

Anti-counterfeiting labels with various fluorescent colors are of great importance in information encryption-decryption, but are still limited to static information display. Therefore, it is urgent to develop new materials and encryption-decryption logic for improving the security level of secret information. In this study, an organohydrogel made up of poly(N,N-dimethylacrylamide) (pDMA) hydrogel network and polyoctadecyl methacrylate (pSMA) organogel network that copolymerized with two fluorophores, 6-acrylamidopicolinic acid moieties (6APA, fluorescent ligand) and spiropyran units (SPMA, photochromic monomer), was prepared by a two-step interpenetrating method. As UV light of 365 nm and 254 nm can both cleave C_spiro-O bonds of SPMA, and the green fluorescence of 6APA-Tb³⁺ can only be excited by 254 nm light, the organohydrogel displays yellow and red under the irradiation of 254 nm and 365 nm, respectively. In addition to wavelength selectivity, these two fluorophores are thermal-responsive, leading to the fluorescence variation of the organohydrogel during heating process. As a result, secret information loaded on the organohydrogel can be decrypted by the irradiation of UV light, and the authenticity of the information can be further identified by thermal stimulation. Our fluorescent organohydrogel can act as an effective anti-counterfeiting label to improve the information security and protect the information from being cracked.     

Porphyrin-based photocatalytic lithography

Photocatalytic lithography couples light with photoreactive coated mask materials to pattern surface chemistry. We excite porphyrins to create radical species that photocatalytically oxidize, and thereby pattern, chemistries in the local vicinity. The technique advantageously is suited for use with a wide variety of substrates. It is fast and robust, and the wavelength of light does not limit the resolution of patterned features. We have patterned proteins and cells to demonstrate the utility of photocatalytic lithography in life science applications.     

Fluorinated polymers: liquid crystalline properties and applications in lithography

Fluorinated polymers form an interesting class of materials with a wealth of unique properties including self-assembly, remarkably low surface energies, low absorbance to 157 nm UV light, and solubility in supercritical carbon dioxide. As a result many fluorinated polymers are of use in advanced technology applications. We review some of our work on the synthesis and characterization of block copolymers with fluorinated side chains, with special emphasis on surfaces formed using these polymers. The use of fluorinated polymers as photoresists for 157 nm lithography, with the possibility for processing in environmentally friendly supercritical carbon dioxide is also discussed.     

Polyphenol derivatives of porphyrins containing fluorene units: Synthesis and positive-tone photoresists for 22-nanometer lithography

A new strategy was proposed for the synthesis of polyphenol derivatives of fluorene-containing porphyrins to be used as the base for positive-tone photoresists for lithography with exposure at 13.5 nm wavelength, which allow fabrication of microchips with a size of down to 22 nm. Polyphenols based on fluorenecontaining porphyrins were synthesized for the first time. It was shown that these polyphenol derivatives can be used to obtain positive-tone photoresists with a resolution of 22 nm.     

氩离子激光固化环氧树脂制作三维微结构

利用激光束进行三维成像是通过逐层光引发聚合形成宏观尺度的三维实体 .最近出现的激光全息光刻技术是利用激光束的干涉产生三维全息图案 ,让感光树脂在全息图案中曝光 ,从而一次形成三维周期有序微结构 .通过调节激光干涉及波长可控制三维结构的形状及尺寸 .利用该技术获得亚微米尺度上周期性重复的三维微结构 ,可用于制作三维光子晶体 [1,2 ]等具有独特性能的聚合物材料 .本文用铁芳烃化合物与特种环氧树脂配制成阳离子型可见光固化树脂 ,在氩离子激光器产生的多束可见连续激光相干形成的空间干涉光场中曝光 ,成功地制备出亚微米量级的三…     

Fabrication of Photoprocessable Materials via Photopolymerization Using an Acid-Induced Photocleavable Platinum-Acetylide Crosslinker

Photopolymerization and photoprocessing are core technologies for molding and tuning polymer materials. However, they are incompatible with single materials owing to their contradictory photoreactivity. Herein, an acid-induced photocleavable crosslinker, a platinum–acetylide complex covered by permethylated cyclodextrins, enables the fabrication of photoprocessable materials via photopolymerization with N-(2-hydroxyethyl)acrylamide. The polymer networks are molded by 365 nm irradiation as well as softened and degraded by a cooperative reaction with HCl as an acidic additive under 365 nm UV light, or 470 nm visible light in the presence of a photosensitizer. Moreover, the crosslinker is applied to a photoadhesive triggered by 365 nm irradiation. The adhesion is detachable on-demand through acid-induced photodegradation with the same wavelength and intensity of irradiation. Thus, acid-induced photocleavage allows the integration of light-induced molding and processing under various lights of various wavelengths, opening up new strategies for polymer technologies.     

The movement of a water droplet on a gradient surface prepared by photodegradation

A hydrophobic to hydrophilic gradient surface was prepared using the tuned photodegradation of an alkylsilane self-assembled monolayer (SAM) using irradiation of vacuum ultraviolet light (wavelength=172 nm). The water contact angle on the photodegraded SAM surface was adjusted using the intensity and time photoirradiation parameters. The formation of a gradient was confirmed by fluorescent labeling. The water drop moved from the hydrophobic to hydrophilic surface with a velocity that depended on the gradient. The higher the gradient, the faster the water moved. For the first time, we have prepared a gradient surface using photodegradation where the movement of a water drop was regulated by the degree of gradation. Considering that the photodegradation technique can be applied to various surfaces and to lithography, this technique will be useful for various material surfaces.     

CsB4O6F: A Congruent‐Melting Deep‐Ultraviolet Nonlinear Optical Material by Combining Superior Functional Units

The discovery of new nonlinear optical (NLO) materials for coherent light generation in the deep‐ultraviolet (DUV, wavelength below 200 nm) region is essential for the development of laser technologies. Herein, we report a new material CsB₄O₆F (CBF), which combines the superior structural properties of two well‐known NLO materials, β‐BaB₂O₄ (BBO) and KBe₂BO₃F₂ (KBBF). CBF exhibits excellent DUV optical properties including a short cutoff edge (155 nm), a large SHG response (≈1.9×KDP), and a suitable birefringence that enables frequency doubling down to 171.6 nm. Remarkably, CBF melts congruently and shows an improved growth habit. In addition, our rational design strategy will contribute to the discovery of DUV NLO materials.     

NIR-II Absorbing Monodispersed Oligomers Based on N−B←N Unit

Organic molecules with near-infrared II (NIR II) light absorption are essential for many biological and opto-electronic applications. Herein, we report monodispersed oligomers as NIR II light absorber using a new molecular design strategy of resonant N−B←N unit, i.e. balanced resonant boron-nitrogen covalent bond (B−N) and boron-nitrogen coordination bond (B←N). We synthesize a series of monodispersed oligomers with thiophene-fused 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (TB), which contains resonant N−B←N unit, as the repeating unit. The TB pentamer exhibits the maximum absorption wavelength of 1169 nm, which is the longest for oligomers reported so far. Organic photodetectors (OPDs) with the TB tetramer as the electron acceptor shows the specific detectivity of 2.98×10¹¹ Jones at 1180 nm under zero bias. This performance is among the best for NIR II OPDs. These results indicate a new kind of NIR II absorbing molecules as excellent opto-electronic materials.     

非晶态硒砷静电复印材料的光致疲劳机理

本工作通过硒基静电复印感光材料的静电电位谱的测定,研究了非晶态As_xSe_100-x(0相似文献   

Soluble alkyl substituted polygermanes: Thermochromic behavior

We have prepared a number of high molecular weight, soluble, symmetrical dialkyl substituted germanium homopolymers and germanium-silicon copolymers. In solution, the absorption of the homopolymers was ～ 20 nm red shifted from the crossponding silicon derivatives. This was somewhat unexpected based on theoretical predictions and has been rationalized on the basis of conformational arguments. In the solid state, samples of poly(di-n-hexylgermane) and poly(di-n-octylgermane) are strongly thermochromic. The effect is attributed to the conformational locking of the backbone which is caused by the crystallization of the side groups. In this regard, the germanium derivatives behave similarly to the corresponding silicon polymers, and the convergence of the long wavelength absorptions for both types of polymers is consistent with theoretical predictions. The germanium-silicon copolymers are also strongly thermochromic, but the long wavelength absorption is somewhat blue shifted (8 nm) from the respective homopolymers. As expected, the new germanium homo and copolymers are quite sensitive to light and readily undergo chain scission to produce lower molecular weight materials.     

Patterned polymer brushes

This critical review summarizes recent developments in the fabrication of patterned polymer brushes. As top-down lithography reaches the length scale of a single macromolecule, the combination with the bottom-up synthesis of polymer brushes by surface-initiated polymerization becomes one main avenue to design new materials for nanotechnology. Recent developments in surface-initiated polymerizations are highlighted along with diverse strategies to create patterned polymer brushes on all length scales based on irradiation (photo- and interference lithography, electron-beam lithography), mechanical contact (scanning probe lithography, soft lithography, nanoimprinting lithography) and on surface forces (capillary force lithography, colloidal lithography, Langmuir-Blodgett lithography) (116 references).     

Nanostructure in energy conversion

Nanostructured and nanosized materials are widely applied to tackle the pressing challenges associated with energy conversion. In this conceptual review, rather than highlighting separate examples, we aim to give a general overview about where and how nanostructure design can be beneficial in the three major research fields(photo)thermal chemical energy conversion, electrochemical energy conversion, and solar energy conversion. It will be shown that in many cases the design of catalytically active nanostructures is the main task and that especially for catalysts nanostructure and activity are inseparably linked to each other. Moreover, electrochemical and photochemical processes are complicated by the overlap of multiple processes that all need to be optimized, including in particular light absorption, charge migration,recombination and trapping events and surface processes. It will also be shown how the development of materials for new challenges can often be based on our knowledge on existing materials for related applications.     

Cholesteric mixture containing a chiral azobenzene-based dopant: material with reversible photoswitching of the pitch of the helix

A new low molar mass chiral-photochromic dopant was synthesized. It contains a menthyl fragment as the chiral group and an azobenzene group, capable of E - Z photoisomerization, as the photochromic component. The substance obtained was used as a chiral dopant in mixtures with a comb-shaped cholesteric acrylic copolymer with menthyl-containing chiral side groups and phenyl benzoate nematogenic side groups. Such mixtures form a cholesteric mesophase. The chiral dopant led to an additional twisting of the cholesteric helix, i.e. to a shift of the selective light reflection peak to a shorter wavelength region of the spectrum. The initial copolymer gave selective light reflection in the spectral range 1200-1400 nm; the mixture containing 3.5 mol % of chiral-photochromic dopant reflects light with λ_max~ 850 nm. The action of light with λ_ir~ 440 nm results in E - Z isomerization of the azo-group of the chiral dopant and in a shift of the selective light reflection peak to the long wavelength region of the spectrum (amplitude of shift = 30 nm). This is explained by a lower helical twisting power of the Z-isomer of the chiral dopant. This process is thermally reversible: annealing of irradiated films leads to a back shift of the selective light reflection peak to the short wavelength region of the spectrum due to Z - E isomerization. Kinetic features of the direct and backward processes of isomerization were studied: it was shown, that mixtures of the chiralphotochromic azobenzene-containing dopant with cholesteric polymers give new possibilities for the creation of polymer materials with a reversibly regulated helical supramolecular structure which determines their optical properties.     

二氧化碳基聚碳酸环己撑酯电子束光刻胶显影工艺优化

电子束光刻是下一代光刻技术中的有力竞争者,在微纳加工尤其是光刻掩膜制造上具有显著的竞争优势。 开发高性能的光刻胶并优化出最佳的显影条件和工艺是提升电子束光刻效率的基础。 本文在前期开发出的二氧化碳基聚碳酸酯电子束光刻胶的基础上,进一步探究了正性聚碳酸环己撑酯(PCHC)胶的显影条件对电子束光刻性能的影响,具体研究了显影剂以及显影温度和时间等工艺条件,筛选出了最优显影剂正己烷,最佳显影温度0 ℃,最佳显影时间30 s。 在该条件下,PCHC的灵敏度和对比度分别为208 μC/cm²和3.06,并实现了53 nm的分辨率,超过了当下广泛使用的PMMA-950k电子束光刻胶,有望为科研院所和半导体加工车间提供一种性能优异、成本低廉的新型电子束光刻胶。     

Organic photovoltaic materials and thin-film solar cells

Organic photovoltaic materials are of interest for their future applications in solar cells. Compared to inorganic or dye-sensitized solar cells, organic photovoltaic (OPV) cells offer a huge potential for low-cost large-area solar cells because of their low material consumption per area and easy processing. In the last few years, there have seen an unprecedented growth of interest in OPVs with power conversion efficiency of over 5% attainable. However, OPV’s performance is limited by the narrow light absorption, poor charge carries mobility, and low stability of organic materials, all of which confine its large-scale commercial applications. This review will develop a discussion on the OPV device configuration and operational mechanism after an introduction of the general features of OPV materials. Subsequently, the typical progresses in materials development and performance evolution in recent years will be summarized. The future challenges and prospects faced by organic photovoltaics will be discussed. Finally, the innovative strategy on research of molecular design and device optimization will be suggested with the aim for practical application.     

Generation of surface energy patterns by single pulse laser interference on self-assembled monolayers

Single pulse laser interference lithography is used to structure self-assembled monolayers of thiols on gold. This structuring process is investigated by attenuated total reflection measurements, and a demixing process of a binary polymer blend is used to visualize the produced surface energy pattern. The lithography can be realized with different wavelengths (266, 532, and 1064 nm) which shows that the structuring is a thermal process. As a first demonstration of this process, structures down to 800 nm period and 300 nm width are fabricated.     

The photoluminescence of Co-Al-layered double hydroxide

We report a new optical behaviour of pure Co-Al-layered double hydroxide (LDH).It was found that the Co-Al-LDH sample could emit fluorescence without any fluorescent substances intercalated.Its excitation spectrum shows a maximum peak near the wavelength 370nm,the maximum emission peak appears at 430 nm and the photoluminescence colour of the Co-Al-LDH sample is blue.This new optical property will be expected to extend the potential applications of LDHs in optical materials field.