非晶硅液晶光阀

本文介绍反射式非晶硅液晶光阀的研制方法，并对其光电性能进行了研究，提出非晶硅液晶光阀的参数设计模型。     

生物基小分子在联苯类液晶材料合成中的应用进展

生物基小分子来源广、价廉,同时大多具有手性,使其在绿色化学盛行的今天作为良好的非介晶基元广泛应用于液晶材料合成研究领域。联苯类液晶因为其良好的物理化学稳定性、较宽的工作温度范围、适当的低黏度,以及快速响应与低电压驱动等优点,在光电显示材料等领域得到了广泛应用。文中综述了近年来薄荷醇、乳酸、糖醇、氨基酸等生物基小分子在联苯类液晶材料合成中的应用进展,指出多生物手性基团结合,特别是与高分子材料的完美组合,是未来研究的新方向。     

液晶光阀中的α-Si:H光导膜研究

本文对在光学信息处理中应用的液晶光阀的关键性膜层——光电导膜采用新近开发的非晶硅材料作了一些探索。研究表明,响应快速的α-Si:H薄膜用于液晶光阀是很有前途的。     

液晶显示材料用偶氮染料的研究进展

二向色性偶氮染料分子结构上的特性和可修饰性,使其在液晶彩色显示中得到重要的应用.与液晶掺杂后这类染料表现出许多良好的光电特性,如具有宽液晶显示的视角、增加显示亮度等.简要介绍与归纳了近几年来发现和新合成的偶氮染料与液晶共混后产生的吸光性质、二向色性以及偶氮染料在液晶中的溶解性和稳定性,并展望了这类染料的合成方向.     

液晶显示器高科技产品项目落户沈阳

10月15日,中外合资沈阳毓鑫园光电科技有限公司液晶显示器高科技产品项目在皇姑北部工业区举行奠基仪式。沈阳毓鑫园光电科技有限公司主要生产销售液晶显示器(LCD)及相关配套的液晶模块(LCM),其产品广泛应用于电子信息行业,属高科技产业项目。项目占地面积60亩,总投资额为2880万美元,预计分二期完成。一     

晶体旋光率测量系统

为了克服以往晶体旋光率测量方法存在误差大、精度低、实用性差等不足,提出了一种基于液晶相位可变延迟器(LCVR)的石英晶体旋光率测量方法。改变液晶相位可变延迟器所加驱动电压,精确控制液晶相位延迟量,对偏振光进行调制。通过偏振光调制法测量斯托克斯(Stokes)参量,从而实时、准确地测量石英晶体旋光率。采用PIN 光电二极管对偏振光信号进行探测,经光电变换后利用信号调理电路实现信号采集。将采集到的数据进行处理并显示。实验结果表明,该方法的测量精度为0.57%。     

铁电驻极体-液晶高弹体光电转换器性能分析

基于在紫外光照下可变形的液晶高弹体与铁电驻极体材料,设计了一种光电转换器模型器件。该模型器件能实现在紫外光照射下的电信号输出功能。建立了光电耦合分析模型,并分析了紫外光光强对产生感应电荷的影响。结果表明,该模型器件可指导开发一种能够测量一定光强范围内紫外光强度的光电传感器。     

友达光电试制出无需电源的柔性电子纸

不久前,在日本横滨举办的一年一度的液晶显示器新品大会FPDInternational上,台湾的友达光电展示了一款新的概念产品——无需电源柔性电子纸显示屏。     

功能侧链液晶聚丙烯酸酯的性能及应用前景

基于国内外最新研究文献，系统论述了新型功能性侧链液晶聚丙烯酸酯的液晶性质，光电性质及应用前景，指出这类聚合物一般显示热致性向列型或近晶型液晶相，液晶相转变温度和液晶态温度范围随链结构的不同发生显著变化，具有较短的电场及光场响应时间，对某些有机物质具有选择吸附能力。可望用作光学信息储存材料，气相色谱固定相材料以及复合材料的界面改性材料等。     

酯类液晶化合物的研究新进展

酯类液晶是近年来广泛应用于高端电子产品的液晶材料.简要评述了酯类液晶的合成进展,并详细讨论了近几年国内外酯类液晶的合成方法及性能,并对其应用前景进行了展望.     

Substrate-induced crystal plastic phase of a discotic liquid crystal

A new phase of a known discotic liquid crystal is observed at the interface with a rigid substrate. The structure of the substrate-induced phase has been characterized by atomic force microscopy, specular X-ray diffraction, and small-angle and wide-angle grazing incidence X-ray diffraction. The substrate-induced phase, which has a thickness of ～30 nm and a tetragonal symmetry, differs notably from the bulk phase. The occurrence of such phase casts a new light on alignment of discotic liquid crystals.     

The effect of size and shape variation in discotic liquid crystals based on triphenylene cores

The triphenylene core provides a versatile platform from which discotic liquid crystals can be constructed. Synthetic advances permit the effect that substantial or subtle variation on structure has on mesophase formation. Through comparison of many derivatives, from our studies and others, it appears that the discotic core should be viewed as the triphenylene unit plus the attached polarizable substituents. Disruption of these extended cores discourages mesophase formation.     

Photoconducting liquid crystals

Major recent advances: ‘High’ mobility photoconduction in the columnar mesophases of disc-shaped (discotic) liquid crystals in which the charge carriers are holes or electrons was discovered in 1995. Prior to this photoconduction in liquid crystals was attributed to photo-generated ions and associated with ‘low’ mobilities. Over the last 7 years our understanding of the mechanism of carrier generation and transport in these novel, self-assembling systems has progressed to the point where we are able to design and manufacture organic semi-conductors with well-defined electronic and physical properties. Serious commercial devices incorporating conducting liquid crystals are finally on the horizon.     

纳米结构太阳能电池材料的研究进展

纳米结构材料是当今科学研究的热点,它应用于太阳能电池具有成本低、稳定性好、光电转化率高等特点.介绍了纳米结构材料,如自组装纳米结构的有机盘状液晶太阳能电池和无机纳米晶太阳能电池材料(主要包括敏化TiO2纳米晶、CdSe和CdTe纳米晶、Si基纳米结构)的研究和应用进展,并展望了这些纳米结构材料作为太阳能电池材料的未来发展.     

Patterning of Discotic Liquid Crystals with Tunable Molecular Orientation for Electronic Applications

The large‐area formation of functional micropatterns with liquid crystals is of great significance for diversified applications in interdisciplinary fields. Meanwhile, the control of molecular alignment in the patterns is fundamental and prerequisite for the adequate exploitation of their photoelectric properties. However, it would be extremely complicated and challenging for discotic liquid crystals (DLCs) to achieve the goal, because they are insensitive to external fields and surface chemistry. Herein, a simple method of patterning and aligning DLCs on flat substrates is disclosed through precise control of the formation and dewetting of the capillary liquid bridges, within which the DLC molecules are confined. Large‐area uniform alignment occurs spontaneously due to directional shearing force when the solvent is slowly evaporated and programmable patterns could be directly generated on desired substrates. Moreover, the in‐plane column direction of DLCs is tunable by slightly tailoring their chemical structures which changes their self‐assembly behaviors in liquid bridges. The patterned DLCs show molecular orientation–dependent charge transport properties and are promising for templating self‐assembly of other materials. The study provides a facile method for manipulation of the macroscopic patterns and microscopic molecular orientation which opens up new opportunities for electronic applications of DLCs.     

盘状液晶的性能及应用

简要介绍了盘状液晶的基本概念、分子结构和相态,综述了盘状液晶的分子结构对相的影响、自组装性能、电导性能、光学性能、磁学和铁电性能方面的最新研究进展.盘状液晶柱状相拥有高的有序性和电荷传输速率,作为新型有机半导体材料具有广阔的应用前景.最后,系统概述了盘状液晶材料的应用,并指出了盘状液晶在应用方面存在的问题以及解决问题的方法和建议.     

New semiconducting multi-branched conjugated molecules based on π-extended triphenylene and its application to organic field-effect transistor

Triphenylene derivatives are the most well-known representatives of discotic liquid crystals forming columnar mesophases. In this work, the authors report on the design and synthesis of new semiconducting materials, based on a triphenylene core, those are solution processable. These molecules have a good solubility and are applicable to soluble processing for organic field-effect transistor (OFET). Their thermal stabilities and dynamic behaviors are suitable for OFET device fabrication. In comparison with all of previous reported triphenylenes derivatives, these molecules have lower bandgap energies. As far as we know, there are few reports on the application of π-extended triphenylene systems to OFET. The semiconducting properties of these molecules were quite promising for further designs of π-extended triphenylene derivatives.     

Electron transport along molecular stacks in discotic liquid crystals

We have previously shown that a new class of quasi-one-dimensional p-type semiconductors can be created by dissolving small amounts of oxidising agents into the hydrocarbon chain matrix of discotic liquid crystals. This paper reports the elucidation of the mechanism of conduction in these new materials. In particular, the ac conductivity of 2,3,6,7,10,11 -hexahexyloxytriphenylene (HAT6) doped with the Lewis acid AlCl₃, has been measured as a function of frequency (10^?3–10⁷ Hz), and temperature in its crystalline solid (K), hexagonal discotic liquid crystal (D_ho) and isotropic liquid (I) phases. In macroscopically aligned K and D_ho phases, the conductivity measured along the column axes is approximately 10³ greater than that in the perpendicular direction. Both components of the conductivity are found to be independent of frequency at low frequencies, but show a power law dependence on frequency (Σ(Ω)～Ω^s, s～0.8) at higher frequencies. This behaviour is characteristic of charge carrier transport by a hopping mechanism. The conductivity data have been analysed in terms of the Scher and Lax theory of hopping transport to obtain the parameters describing this process. The conduction along the columns is identified with a single charge transport process in which the carriers hop between localized states (radical cations) associated with counterions (perceived as AlCl₄ ^?) linearly distributed off-axis along the columns.     

New semiconducting multi-branched conjugated molecules based on π-extended triphenylene and its application to organic field-effect transistor

Triphenylene derivatives are the most well-known representatives of discotic liquid crystals forming columnar mesophases. In this work, the authors report on the design and synthesis of new semiconducting materials, based on a triphenylene core, those are solution processable. These molecules have a good solubility and are applicable to soluble processing for organic field-effect transistor (OFET). Their thermal stabilities and dynamic behaviors are suitable for OFET device fabrication. In comparison with all of previous reported triphenylenes derivatives, these molecules have lower bandgap energies. As far as we know, there are few reports on the application of π-extended triphenylene systems to OFET. The semiconducting properties of these molecules were quite promising for further designs of π-extended triphenylene derivatives.     

Viscous Behavior and Shear-Induced Structural Changes in Perfectly Oriented Liquid Crystals

The anisotropy of the viscosity and shear-induced structural changes are studied via nonequilibrium molecular dynamics (NEMD) simulations for two types of model liquid crystals which possess both isotropic and smectic phases. These models are (a) perfectly oriented Gay–Berne particles and (b) r ^–12-soft-spheres plus an r ^–6-interaction with a P ₂-anisotropy. Results are presented for the Miesowicz viscosity coefficients in the nematic phase. Presmectic effects are observed. Structural changes are revealed by snapshots of configurations and by the static structure factor, presented in analogy to scattering experiments. The shear-induced transition from the smectic to the nematic phase is analyzed. Similarities between magnetorheological fluids and discotic systems which can form columnar phases are discussed.