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Coating-type polarizing films with a high dichroic ratio (DR) and polarization efficiency in the visible region were fabricated using a solution of ternary lyotropic chromonic liquid crystals (LCLCs). Optical characteristics of these anisotropic LCLC polarizing films were then determined. DR increased with increasing LCLC concentrations. Molecular ordering of these LCLCs on a rubbed polyimide (PI) layer increased because LCLC molecules' orientation was enhanced by the dielectric anisotropy effect from rubbing the surface of the PI. In addition, this study demonstrated how the interaction between liquid crystal aggregates and the PI surface with different LCLC solutions correlated with LCLC molecular orientations on the PI which is significantly dependent on whether the coating direction of the LCLC solution was parallel or perpendicular to the PI rubbing direction. It was found that the ordering direction at high LCLC concentrations was determined by shearing direction of the LCLC solution coating, whereas the ordering direction at low LCLC concentrations was governed by the dielectric anisotropy effect from the PI rubbing direction.

A new benzodithiophene based donor-acceptor π-conjugated polymer (P1) is designed and explored as the photoactive donor for organic solar cells (OSCs). The synthesized donor polymer, P1 displays a wide absorption profile ranging from 300–750 nm with optical band gap of 1.61 eV and moderate ionization potential of −5.30 eV. It has good solubility in non-halogenated and halogenated organic solvents. Next, we fabricated OSCs with P1 by blending with PC71BM, the pristine polymer processed from chlorobenzene showed PCE of 2.79%. Upon addition of external additive diphenyl ether to the blend showed a dramatic improvement in PCE with maximum of 5.33%. DPE tailored the active layer morphology and showed two times higher PCE than pristine films. These results clearly indicate that the new polymer has a great potentiality for enhancing efficiency upon solvent additives, which will provide new routes for the development of new class of polymers for high-performance air-stable OSCs. [Figure not available: see fulltext.].

High-quality alignment of liquid crystals (LCs) for large area display has been highly demanding for display market. To achieve a uniform and stable LC alignment, a photoresponsive azo-polyimide with two different substitution ratio of azo-dye moiety in the side chain of the polyimide has been successfully synthesized and characterized. Depending on the ratio of azo-dye substitutions, the solubility and coating nature of polyimides vary greatly and initially show random planar or homeotropic alignment of LCs. In situ photoalignment process has been performed to achieve a homogeneous planar alignment of LCs from the initial random planar state and a uniform pretilt state from the initial homeotropic cells using linearly polarized visible light (LPVL) irradiation in the isotropic phase of LCs. Furthermore, obtained alignment states have been stabilized using unpolarized UV light for RM polymerization in the nematic phase of LCs. Hence, the dual wavelength photoalignment approach has been successfully implemented to obtain the different stable alignments of LCs. Also, the results conclude that the tilt angle varies by dose of LPVL irradiation and gets significantly altered due to change in reactive mesogen (RM) concentrations. The surface investigations reveal a contrasting nature for the planar and vertically aligned substrates before and after RM stabilization.

The process of inducing crystallization on the surface of a 50-nm-thick amorphous Si (a-Si) thin film was analyzed by applying a Nd:YAG (λ = 355 nm) nanosecond laser with an asymmetric Gaussian shape at a pulse repetition rate of 14 kHz and pulse duration of 5.5 ns. Single-laser-pulse irradiation with a peak fluence of 124 mJ/cm2 resulted in the formation of circular Si nanoparticles on the surface, which was observed to have multiple domains with varying degrees of surface roughness and crystallinity. Additionally, the light absorption significantly increased at the center of irradiation, where the density of the nanoparticles was maximized. Specifically, at the ultraviolet wavelength of 380 nm, the absorption was 85%, which is approximately twice that for the non-laser-treated a-Si (i.e., 42%). These results are attributable to the anti-reflection effect of the Si nanoparticles, and have been validated by numerical simulations. Although the intensity and absorption were observed to be heterogeneous, it is suggested that uniform crystallinity can be achieved by optimizing the scan pitch and laser fluence; these conditions would enable application of a 355-nm nanosecond laser to the laser crystallization process for organic light-emitting diode displays or photovoltaic devices.

In this study, we report two efficient intramolecular charge transfer (ICT) compounds with versatile functionality as hole transporting layers (HTL) and hosts in emission layer (EML) of phosphorescent organic light emitting diodes (Ph-OLEDs) with donor-acceptor-donor structures. In both molecules, 9,9′-spirobifluorene (SBF) was employed as a common electron acceptor, while phenoxazine (PXZ) or phenothiazine (PTZ) were used as donors. The molecules 2,7-di(10H-phenoxazin-10-yl)-9,9′-spirobi[fluorene] (SBF-PXZ) and 2,7-di(10H-phenothiazin-10-yl)-9,9′-spirobi[fluorene] (SBF-PTZ) were synthesized via a Buckwald-Hartwig cross-coupling reaction in a single step that exhibited typical ICT phenomena. The extremely twisted geometrical configurations of SBF-PXZ and SBF-PTZ may allow for effective intramolecular charge-transfer. Both molecules exhibited strong absorption and emission characteristics in the visible region in solution as well as in the thin film form; significant positive solvatochromism was also observed for both compounds. The replacement of PTZ donor with the PXZ donor caused a bandgap reduction together with an improved ionization potential (IP). The deeper IP (>5.1 eV), greater glass transition temperature, and higher hole mobility extracted from the hole only devices of both molecules revealed them as superior candidates for HTL applications (with/without exciton blocking layers) in Ph-OLEDs. It is further corroborated by the enhanced half-life time of Ph-OLEDs with SBF-PXZ/SBF-PTZ HTLs. Moreover, the OLED performances with SBF-PTZ and SBF-PXZ as EMLs and hosts for phosphorescent dopant OLEDs have exemplified the versatility of the proposed ICT compounds.

In this study, we present the comparison of device performance measurements for organic light emitting diodes using a spectroradiometer through the viewing angle and integrating sphere, widely used for device measurements. The mean calculation method using these results was applied to convert the spectroradiometer (under different viewing angles) data to match with the integrating sphere measurements. The conversion of the spectroradiometer based quantum efficiency and electroluminescence data from all different angular emission patterns was similar to that of the integrating sphere data within a reasonable range of deviation. As such, it is possible to reduce the recurring costs and required time between these two measurement techniques by bypassing the integrating sphere measurement.

A water-soluble aromatic polyamide (WAPA) thin film was formed by coating a newly synthesized poly(2,2′-disulfo-4,4′-benzidine isophthalamide) cesium salt (PDBI-Cs). Its electro-optical properties as an alignment layer in liquid crystal devices were analyzed. Twisted nematic-liquid crystal cells containing WAPA alignment layers annealed at a low temperature of 100 °C showed high voltage holding ratio values above 95 % at a frame rate of 60 Hz, a fast response time of 7.18 ms at ac operation of 1 kHz under LC-applied voltage of 5 V, and excellent contrast ratio of 3284 due to the high optical anisotropy effect of the WAPA surface. Thus, PDBI-Cs-based WAPA can be a promising candidate as a new eco-friendly low-temperature-processable alignment layer for flexible electro-optic devices.

A Nd:YAG (λ = 355 nm) nanosecond laser is used to anneal a 45-nm-thick amorphous-Si (a-Si) thin film on a glass substrate. Via scanning with a laser beam having a Gaussian shape at a repetition rate of 14 kHz, the surface of the a-Si film is crystallized, and laser-induced periodic surface structures (LIPSSs) are formed within the fluence range of 30–35 mJ/cm2. The formation energy of surface ripples is significantly lower than the typical fluence of a few 100 mJ/cm2. Confocal Raman spectroscopy and atomic force microscopy reveal that the a-Si film is only crystallized near the top surface and that the surface ripples are aligned to the perpendicular direction of laser polarization, in accordance with the LIPSS model. For a laser fluence of >35 mJ/cm2, the surface texture loses its periodicity but forms randomly distributed Si grains with a surface roughness of >40 nm. The laser processing on an a-Si film achieved by scanning up to 20 × 20 mm2 shows uniform periodic surface textures, which can be employed in the display or photovoltaic applications.

We perform optical, surface anchoring, and textural studies of an organo-siloxane “tetrapode” material in the broad temperature range of the nematic phase. The optical, structural, and topological features are compatible with the uniaxial nematic order rather than with the biaxial nematic order, in the entire nematic temperature range −25 °C < T < 46 °C studied. For homeotropic alignment, the material experiences surface anchoring transition, but the director can be realigned into an optically uniaxial texture by applying a sufficiently strong electric field. The topological features of textures in cylindrical capillaries, in spherical droplets and around colloidal inclusions are consistent with the uniaxial character of the long-range nematic order. In particular, we observe isolated surface point defects – boojums and bulk point defects – hedgehogs that can exist only in the uniaxial nematic liquid crystal.

We propose a vertical alignment (VA) liquid crystal (LC) device with reduced off-axis gamma shift. We can form a multi-domain structure by simply designing the electrode structure . By applying a different bias voltage to each sub-pixel, we obtained a threshold voltage difference of 2.4 V, without any complex manufacturing process. We confirmed that the off-axis gamma shift can be significantly reduced by the proposed method. We believe that the proposed method can be easily applied to reduce the off-axis gamma shift in vertical alignment LC devices.

The electro-optical hysteresis characteristics in a blue phase liquid crystal system showing multi-domain platelet type body-centred cubic (BP-I) structure at different levels of applied electric field have been investigated. The BP-I state possesses a large degree of hysteresis due to its compact body-centred cubic structure. The hysteresis behaviour is discussed in the context of simulation and theoretical studies reported earlier. When the cell is driven with a low frequency square wave, a novel optically isotropic state with high value of the Kerr constant has been observed. Hysteresis and response time both show relatively lower values in this state with respect to the multi-domain BP-I state.

We address the status of oxadiazole mesogens, C7 and C12, reported to show the biaxial nematic phase, by exploring material aspects (chemical stability, surface anchoring, optical and dielectric properties, topological defects) linked to the type of nematic order. We demonstrate that the isogyres splitting in conoscopic patterns of homeotropic state depends on sample thickness and is associated with variations of molecular tilt along the normal to substrates. We observe isolated topological point defects (boojums and hedgehogs), as well as nonsingular “escaped” disclinations pertinent only to the uniaxial nematic order. Our conclusion is that C7 and C12 feature only a uniaxial nematic phase and the apparent biaxiality is caused by surface effects.

Recently, the display of liquid crystal having the blue phase have been studied more intensively because it has many merits such as wide viewing angle without compensation films, very fast switching response time, and no need for the alignment layer and the rubbing process. First, we confirmed the feasibility of the blue phase liquid crystal display by means of polymer stabilization in the test cell. Even though we could get a wide temperature range that shows the blue phase, there were still problems such as the high operation voltage, hysteresis so on. In 2008, by developing and applying new technologies for improving these characteristics, we successfully fabricated a new kind of the liquid crystal display using the blue phase for the first time in the world.

We have studied a pixel-isolated phase-separated composite organic film (PI-PSCOF). This PI-PSCOF is used for anisotropic phase separation from ferroelectric liquid crystals (FLCs) and prepolymer materials using an appropriate UV intensity variation. In this device, the FLC molecules are isolated in the pixels where FLCs are surrounded by the interpixel vertical polymer walls and the horizontal polymer films on the upper substrate. These devices show very short response time and very high mechanical durability against external pressure. We also compared the pure FLC, conventional phase-separated composite film (PSCOF) and PI-PSCOF mode in terms of their electrooptic characteristics and X-ray layer structure measurements. Compared with the PSCOF mode, PI-PSCOF exhibits good electrooptical behaviors. Consequently, we achieved an excellent device scheme suitable for flexible substrates, using the PI-PSCOF mode and expect that this PI-PSCOF scheme will be one of the powerful and promising new FLC display modes, particularly applicable to flexible FLC display modes.

The pi-cell is one of the candidates for replacing the twisted nematic (TN) and in-plane switching (IPS) modes. It has a fast switching speed and a good viewing angle owing to its self-compensated director configuration. In this paper, we report the optimized conditions for polymer-network stabilization to prevent the bend state from transforming into the (transitioning) splay state. Excellent electro-optical characteristic were obtained by optimizing various conditions: monomer concentrations in liquid crystal (LC), UV intensity, curing time, curing voltage, curing temperature and the retardation of the compensation film. Scanning electron microscopy (SEM) images revealed the structures of the stabilized polymer network in a pi-cell, which is the key factor for maintaining the bend state.

The authors report X-ray scattering experiments on phase-separated composite organic film (PSCOF) structures mixed with ferroelectric liquid crystals (FLCs). We discuss the effect of the local layer structure in a PSCOF cell on the ratio of the concentration between prepolymer and liquid crystals. The ratio of optimized concentration in terms of optical characteristics for a PSCOF liquid crystal display are 30 wt % for prepolymer (NOA65) and 70 wt % for FLCs (Felix). We found that the layer structure in a ferroelectric liquid crystal cell made of 30 wt % NOA65 and 70 wt % Felix is a tilted-bookshelf layer structure. The angles 15 and 17° are the tilted-bookshelf angles at 65 and 58 °C, respectively. These layer tilt angles are almost same as the molecular tilt angles of ferroelectric liquid crystals in the Sm C* phase. We understand that this result comes from compensating for layer buckling. We consider that the PSCOF-mode local layer structure is an excellent solution to the problem of zig-zag defects and mechanical shock for application in future televisions and plastic ferroelectric liquid crystal displays (FLCDs).

The adsorption and desorption of the ions are closely related to the image sticking of liquid crystal (LC) cells. We made an effort to measure the fixed quantity of ion concentration by measuring the residual DC voltage in LC cell and the surface anchoring energy in PVA cell. To understand the mechanism of image sticking, we studied these adsorption and desorption activation energy and found that the desorption activation energy increases as the surface anchoring energy does, and this relationship is rather universal. This observation led us to a conclusion that smaller anchoring energy is required to reduce the image sticking of LC cells.

Six banana‐shaped compounds with a central core based on a 4,6‐dichloro‐1,3‐phenylene group were synthesized by varying the terminal chains (R = OC10H21 or OC11H21) and the lateral substituents (X = H, F or Cl). Their mesophases were characterized by a combination of differential scanning calorimetry, polarizing optical microscopy, triangular wave method, and X‐ray diffractometry. Mesomorphic properties of the banana‐shaped mesogens with an olefinic group (R = OC11H21) as a terminal chain are sensitive to lateral halogen substituents as much as those of the analogues with a saturated group (R = OC10H21). The compounds with X = F showed an antiferroelectric switchable smectic phase, which has been designated a B2 phase. The compounds without a lateral halogen substituent only formed a nematic phase, while the compounds with X = Cl did not exhibit a mesophase in the melt.

The results of precision heat capacity measurements near the lower consolute point in aqueous solutions of non-ionic surfactants n-dodecyl hexaethylene glycol monoether (C12E6), C10E6, and C12E8, are reported. These surfactants form homogeneous single phase micellar solutions below the lower consolute point, Tc. The pretransitional specific heat in the homogeneous phase below Tc is found to grow with temperature and exhibits a power-law divergence. Analysis of the data obtained for the three systems reveals that the specific heat exponent, α=-αR/(1-αR)≅0.5, gives credence to mean field behavior.

Three banana-shaped achiral compounds, derivatives of 4-chloro-1,3-phenylene bis[4-(4-n-decanyloxyphenyliminomethyl)benzoate], were synthesized with variation of a substituent (X=H, F, or Cl); their antiferroelectric properties are described. The mesomorphic and switching properties were characterized by polarizing optical microscopy, differential scanning calorimetry, triangular wave method, and X-ray diffraction. The introduction of a lateral halogen substituent in the Schiff's base moiety prevents the regular stacking of the molecules, resulting in a decrease of melting temperature and leads to formation of the switchable SmC* phase in the melt. All of the compounds showed antiferroelectric switching, and their values of spontaneous polarization on reversal of an applied electric field were 260, 480, and 300 nC cm−2, respectively, for X=H, F and Cl.

Twelve azomethine polymers containing a banana-shaped mesogen as a repeating unit have been synthesized by polycondensation, and their mesomorphic properties were studied. The solution viscosities ...

New chiral bent-core mesogens, derivatives of 1,3-phenylene bis[4-(alkanyloxyphenyliminomethyl)benzoate], were synthesized with variation of a substituent (X=F, Cl); their antiferroelectric properties are described. The mesomorphic and switching properties were characterized by differential scanning calorimetry, polarizing optical microscopy, triangular wave method, and X-ray diffractometry in the small and wide angle regions. The presence of chiral tails at the terminals of side wings in the bent-core molecules induced a decrease in transition temperature and formation of the switchable SmC* phase in the melt. In addition, the introduction of a lateral halogen substituent in the Schiff's base moiety prevented the regular stacking of the molecules, resulting in the formation of very complex optical textures. The smectic phase with F-substituted PBFDOB and Cl-substituted PBCDOB showed layer spacings of 39 and 38.5 A, respectively, corresponding to the end-to-end distance of molecules with a bent conformati...

Three banana-shaped achiral compounds, derivatives of 4,6-dichloro-1,3-phenylene bis-[4-(4-n-octyloxyphenyliminomethyl) benzoate], were synthesized by varying the substituent (X = H, F and Cl). Their mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy, and X-ray analysis. The compound with X = H exhibited an enantiomeric nematic phase. The compounds with X = F and Cl formed a nematic phase on heating, while on cooling they formed a nematic phase at high temperature and a smectic A phase at a lower temperature (monotropic). A schematic representation of the mesophase structures for the compound with X = F is also illustrated.

We fabricated an inverse four domain twisted nematic (IFDTN) mode using a stacked photo-alignment layer enhancing the azimuthal anchoring energy. The strong anchoring energy generates the stable 4D twist structures under an applying voltage. High transmittance and contrast device is achieved without complex rubbing processes.

We investigate the origin of secondary disclinations that were recently described as a new evidence of a biaxial nematic phase in an oxadiazole bent-core thermotropic liquid crystal C7. With an assortment of optical techniques such as polarizing optical microscopy, LC PolScope, and fluorescence confocal polarizing microscopy, we demonstrate that the secondary disclinations represent non-singular domain walls formed in an uniaxial nematic during the surface anchoring transition, in which surface orientation of the director changes from tangential (parallel to the bounding plates) to tilted. Each domain wall separates two regions with the director tilted in opposite azimuthal directions. At the centre of the wall, the director remains parallel to the bonding plates. The domain walls can be easily removed by applying a modest electric field. The anchoring transition is explained by the balance of (a) the intrinsic perpendicular surface anchoring produced by the polyimide aligning layer and (b) tangential alignment caused by ionic impurities forming electric double layers. The model is supported by the fact that the temperature of the tangential-tilted anchoring transition decreases as the cell thickness increases and as the concentration of ionic species (added salt) increases. We also demonstrate that the surface alignment is strongly affected by thermal degradation of the samples. The study shows that C7 exhibits only a uniaxial nematic phase and demonstrate yet another mechanism (formation of secondary disclinations) by which a uniaxial nematic can mimic a biaxial nematic behaviour., 21 pages, 9 Figures, 1 Table

Two series of new liquid crystalline compounds containing a non-activated arylazoindolinobenzospiropyran, ABP-SPAB 1a-1e (series 1) and SPAP-ABPC 2a-2e (series 2), have been synthesized. These LC dyes were characterized by a differential scanning calorimetry polarizing optical microscopy, X-ray diffraction and electro-optical measurements. All but one of the series 1 compounds examined exhibit monotropic second and/or third transition liquid crystal phases on cooling from the isotropic liquid. In particular, ABP-SPAB 1b shows a monotropic SmC phase, in addition to a SmA phase. In series 2, most of the compounds exhibit a monotropic nematic phase on cooling. SPAP-ABPC 2c forms an enantiotropic nematic phase and a monotropic SmA phase; 2e shows enantiotropic nematic and SmA phases.

Two series of liquid crystalline dyes (series 1 and 2) containing novel mesogens incorporating a non-activated spiropyranylazo group have been synthesized. Those mesogens are derived from [1′,3′,3′-trimethylspiro(2H-1-benzopyran-2,2′-indoline)-6-yl] azobenzoic acid and 6-(p-hydroxyphenylazo)-1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indoline] for the series 1 and 2, respectively. Their liquid crystalline properties were studied by differential scanning calorimetry, optical polarizing microscopy and electro-optical measurement. Most of the compounds in series 1 form the enantiotropic nematic phase, while compounds in series 2 form the monotropic nematic and SmA phase.

The effects of surface morphology on domain formation and relaxation in ferroelectric materials have been investigated. Comparison of the topography of triglycine sulfate with its ferroelectric domain image reveals a deterministic behavior in the formation of the equilibrium domain configuration. It is observed that defects such as crystal imperfections, cleavage steps and strained lines make ferroelectric state more stable by suppressing short-range repulsion, which results in domain pinning. On the other hand, it can be seen that long-range interaction is screened by free carriers in the metallic film. For this reason, we can see the domain movement beneath the metallic film is faster than that in bare surface.

We have studied the effect of molecular chirality and cell gap on the electro-optic (EO) modulation associated with a homeotropic to twisted-planar (HTP) transition. It is found that an optimum condition of the cell gap and the corresponding chirality exists for the maximum EO modulation. A surface layer of the HTP structure is somewhat thicker than that of a conventional twisted nematic one. The helical pitch predominantly governs waveguiding characteristics and the resultant EO properties of the HTP structure. The polar and azimuthal surface anchoring on treated homeotropic alignment layers is also discussed.

We have studied the light leakage mechanism of the protruded electrode used for blue phase LCD. According to our study, the light leakage can be reduced by identical refractive indices of the protrusion and BPLC.

The results of specific-heat measurements at the nematic- (N) to-neat-soap (NS) and nematic-to-isotropic (I) phase transitions in binary mixtures of cesium-perfluoro-octanoate and water are reported. The ratio of specific-heat amplitudes above and below the N-NS transition, A + /A − , and the specific-heat exponent a remain ∼1.0 and ≤0.02, respectively, suggesting 3D XY-type behavior; At the first-order N-I transition, the vanishing latent heat and coexistence range at low concentration indicate the existence of a Landau point

Three banana-shaped achiral compounds, 4-chloro-1,3-phenylene bis [4-{4-(undecenyloxy)phenyl iminomethyl}benzoate] derivatives, were synthesized with variation of a substituent (x=H, F, Cl); their antiferroelectric properties are described. The smectic mesophases, including a switchable chiral smectic C(Sm C*) phase, were characterized by differential scanning calorimetry, polarizing optical microscopy, triangular wave method, and X-ray diffractometry. The presence of vinyl groups at the terminals of linear side wings in the banana-shaped achiral molecules induced a decrease in melting temperature and formation of the switchable Sm C* phase in the melt. The smectic phase having a lateral fluorine-substituent at 3-position of the Schiffs base moiety showed antiferroelctric switching, and the value of spontaneous polarization on reversal of an applied electric field was 250 nC/cm 2 .

A homeotropic to twisted‐planar (HTP) structural transition is demonstrated in a homeotropically aligned nematic liquid crystal with negative dielectric anisotropy. This HTP transition results in a novel electro‐optic effect useful for extremely high contrast, wide viewing, and achromatic display applications. The HTP architecture is found to be a promising candidate for use in the active addressing scheme. The role of the surface anchoring and molecular chirality on the HTP transition is also discussed.

Coexisting polar and nonpolar domains have been studied by means of texture observation, x-ray analysis, optical second-harmonic generation (SHG), and SHG microscopy in the ${B}_{7}$ phase of a bent-core mesogen doped with azo dyes. The bent-core molecules take a planar orientation and show high birefringence in the polar domain, while they take a homeotropic orientation and show low birefringence in the nonpolar domain. Good correspondence between real and SHG images was observed under a SHG microscope; the bright (high-birefringent) domain is SHG active and the dark (low-birefringent) domain is not SHG active. Photoisomerization of the azo dyes causes layer reorientation from the layer perpendicular to the substrate to that parallel to it.

The properties such as cell gap, pretilt angle and rubbing direction in the multi domain PS(polymer stabilized)-VA cell were measured by a optical method. It has been impossible to measure the pretilt angle in sub micrometer area because liquid crystals in each area of the 4-domain PS-VA cell have different pretilt angle in the other direction. We could get the data using the optical measurement system merged microscope. Many failure muras caused during the liquid crystals process is analyzed successfully through the measurements. It is also very powerful tool to measure the cell gap below the protrusion in the pixel.

We propose a method for in-plane switching of vertically aligned negative liquid crystals (LCs) for high transmittance and wide viewing angle. By applying an in-plane electric field using a double-layered electrode structure, LC molecules can be rotated by the vertical as well as the in-plane components of the applied field over the entire region so that high transmittance can be achieved. The threshold voltage difference can be obtained simply by varying the electrode structure, which can reduce the off-axis gamma shift in a multidomain vertical alignment LC cell.

The melting of lipid-based microcylinders (tubules) has been investigated for systems with single and multiple bilayer walls using high field, magnetic birefringence, and precision microcalorimetry. The pretransitional behavior of both the magnetic birefringence and the specific heat is very different in tubules with a single bilayer wall from that of tubules with multiple bilayers.

In this paper, we propose a stable four-domain twisted nematic structure with wide viewing angle characteristics and a fast response time. A stable structure was realized by introducing a high pre-tilt angle approach incorporating stacked planar and vertical alignment layers. The response time and thermal stability of the proposed device were dramatically improved by the addition of UV-curable reactive mesogen (RM) mixed with a vertical alignment material. Polymerized RMs along the liquid crystal (LC) director increased the polar anchoring energy and reduced back-flow phenomena. A wide viewing angle and fast response time characteristics were achieved over all gray levels.

The mechanism of light leakage in the dark state of a blue phase liquid crystal display cell which has protruded electrodes was investigated. We have performed a hybrid numerical simulation by combining the geometrical optics with the extended Jones matrix method. The light leakage in the cell was caused by changes in the polarization state which has been explained by the asymmetric amplitude change of transverse electric and transverse magnetic fields at the oblique interface and the change in an effective angle between crossed polarizers by the light path refraction. Based on our analysis, light leakage can be suppressed by the matching of the refractive indices of adjacent materials to the interface of the protruded electrodes whose surfaces are not parallel to the substrate.