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Scanning tunneling microscopy shows that copper deposited at room temperature onto a freshly exfoliated MoS2 surface forms Cu(111) clusters with periodic preferred heights of 5, 8, and 11 atomic layers. These height intervals correlate with Fermi nesting regions along the necks of the bulk Cu Fermi surface, indicating a connection between physical and electronic structures. Density functional theory calculations of freestanding Cu(111) films support this as well, predicting a lower density of states at the Fermi level for these preferred heights. This is consistent with other noble metals deposited on MoS2 that exhibit electronic growth, in which the metal films self-assemble as nanostructures minimizing quantum electronic energies. Here, we have discovered that it is critical for the metal deposition to begin on a clean MoS2 surface. If copper is deposited onto an already Cu coated surface, even if the original film displays electronic growth, the resulting Cu film lacks quantization. Instead, the preferred heights of the Cu clusters simply increase linearly with the amount of Cu deposited upon the surface. We believe this is due to different bonding conditions during the initial stages of growth. Newly deposited copper would bond strongly to the already present copper clusters, rather than the weak bonding, which exists to the van der Waals terminated surface of MoS2. The stronger bonding with previously deposited clusters hinders additional Cu atoms from reaching their lowest quantum energy state. The interface characteristics of the van der Waals surface enable surface engineering of self-assembled structures to achieve different applications. [ABSTRACT FROM AUTHOR]

Scanning tunneling microscopy shows that copper deposited at room temperature onto a freshly exfoliated MoS2 surface forms Cu(111) clusters with periodic preferred heights of 5, 8, and 11 atomic layers. These height intervals correlate with Fermi nesting regions along the necks of the bulk Cu Fermi surface, indicating a connection between physical and electronic structures. Density functional theory calculations of freestanding Cu(111) films support this as well, predicting a lower density of states at the Fermi level for these preferred heights. This is consistent with other noble metals deposited on MoS2 that exhibit electronic growth, in which the metal films self-assemble as nanostructures minimizing quantum electronic energies. Here, we have discovered that it is critical for the metal deposition to begin on a clean MoS2 surface. If copper is deposited onto an already Cu coated surface, even if the original film displays electronic growth, the resulting Cu film lacks quantization. Instead, the preferred heights of the Cu clusters simply increase linearly with the amount of Cu deposited upon the surface. We believe this is due to different bonding conditions during the initial stages of growth. Newly deposited copper would bond strongly to the already present copper clusters, rather than the weak bonding, which exists to the van der Waals terminated surface of MoS2. The stronger bonding with previously deposited clusters hinders additional Cu atoms from reaching their lowest quantum energy state. The interface characteristics of the van der Waals surface enable surface engineering of self-assembled structures to achieve different applications. [ABSTRACT FROM AUTHOR]

High-entropy pyrochlore iridates A2Ir2O7 with multiple trivalent A cations were synthesized. The parent ternary A2Ir2O7 displays a variety of electronic phases depending on the size of A cations; Pr2Ir2O7 with a large A cation shows semimetallic behavior down to low temperatures, whereas A2Ir2O7 with smaller A cations, such as Nd2Ir2O7 and Eu2Ir2O7, displays a (semi)metal to magnetic insulator transition as a function of temperature. By further reducing the A cation size, smaller than Y3+, A2Ir2O7 becomes a Mott insulator, and long-range magnetic order takes place below room temperature. The metal–insulator transition and magnetic ordering turned out to be robust against strong disorder induced by the mixing of more than five A-cations in the high-entropy A2Ir2O7. The transition temperatures were found to scale with the average ionic radius of multiple A-cations. In contrast, high-entropy A2Ir2O7 including Bi3+ exhibits metallic behavior down to 2 K, which is likely associated with the presence of oxygen vacancies as in the parent Bi2Ir2O7. Although these indicate that the overall electronic structure of A2Ir2O7 remains intact in the presence of high-entropy configuration at the A-site, the transport properties suggest that fine details of the band structure may be modulated by local distortion. Strong disorder at the A-site of complex oxides may be exploited as a tool to control electronic properties. [ABSTRACT FROM AUTHOR]

Attaining highly uniform operations in a disordered system presents a persistent challenge. The utilization of ion migration in amorphous materials to trigger the resistive switching process of the material usually results in inferior uniformity of the memristive device. Here, we demonstrate that the resistive switching behavior can be activated through carrier doping in the disorder system, and highly ordered resistance modulation is achieved in Ag-doped albumen. By manipulating the doping level of the carrier, the localization of the free electron wavefunction can be tuned, leading to multi-level variations in resistance. This memristive switching behavior is in all electronic and displays excellent switching uniformity, holding great potential for applications in high-density memories and neuromorphic computing chips. [ABSTRACT FROM AUTHOR]

Multiplexing technologies can be used as a platform for low-cost, high-performance, and large-capacity holographic displays and data storage systems. In this paper, a polarization multiplexed method is proposed to realize two different information channels under orthogonally linear-polarized incidences utilizing the coding metasurface. Based on the modified weighted Gerchberg–Saxton (GSW) algorithm, a two-bit coding metasurface is designed with a set of double-layer cross-type meta-atoms to encode the holographic phase information, which can reflect two independent holographic images with respect to different incident polarization. The experimental results agree well with the numerical simulations and the theoretical predictions, which make the proposed multiplexed two-bit coding meta-hologram a great potential in numerous applications such as data storage and information processing. [ABSTRACT FROM AUTHOR]

Blue and ultraviolet radiation is well known to be associated with cataract formation and visual damage. Nowadays, children and teenagers are increasingly exposed to blue light and electromagnetic radiation with even shorter wavelength, which may cause damage to vision due to their frequent use of electronic display devices and participation in disco parties and concerts with illumination by UV light. We developed a Fe:Pd/ZnSe Schottky barrier photodetector that detects blue and UV light with excellent long-wavelength rejection power for green and red light of 4.24 and 5.65 orders, respectively. Its Schottky-barrier height and built-in potential are determined to be 2.48 and 1.17 eV, respectively. Together with the help of a lux meter, this simple and robust photodetector detects the blue light + UV content of different LED light bulbs with accuracy comparable to the much more sophisticated and expensive spectrometer. This compact and efficient blue + UV light detector can help us to increase the awareness of over-exposure to vision damaging radiation. [ABSTRACT FROM AUTHOR]

By working under the framework of the Helmholtz potential as a functional of the equilibrium density matrix, in this contribution, we provide theoretical evidence about a particular thermodynamic situation, where electronic species display their highest susceptibility to exchange electrons to or from surroundings. This situation is denominated as the electronic temperature condition. Neutral chemical species display their lowest possible hardness value at the electronic temperature condition, and remarkably, under this circumstance, the exchange of any amount of electronic charge will necessarily be translated into a net increase in the corresponding chemical hardness. Chemical response functions defined as partial derivatives of the Helmholtz potential with respect to the (average) number of electrons and evaluated at the electronic temperature condition provide comparable results than those obtained from the coarse quadratic approximation to the exact dependence of the electronic energy vs the number of electrons, including composite quantities as the electrophilicity index. In this context, we show that the exact Helmholtz potential dependence with respect to the number of electrons can accurately be approximated by "temperature dependent" polynomial fits (up to fourth order), evaluated at the electronic temperature condition. [ABSTRACT FROM AUTHOR]

Graphene bilayers display peculiar electronic and mechanical characteristics associated with their two-dimensional character and relative disposition of the sheets. Here, we study nuclear quantum effects in graphene bilayers by using path-integral molecular dynamics simulations, which allow us to consider quantization of vibrational modes and study the effect of anharmonicity on physical variables. Finite-temperature properties are analyzed in the range from 12 to 2000 K. Our results for graphene bilayers are compared with those found for graphene monolayers and graphite. Nuclear quantum effects turn out to be appreciable in the layer area and interlayer distance at finite temperatures. Differences in the behavior of in-plane and real areas of the graphene sheets are discussed. The interlayer spacing has a zero-point expansion of 1.5 × 10−2 Å with respect to the classical minimum. The compressibility of graphene bilayers in the out-of-plane direction is found to be similar to that of graphite at low temperatures and increases faster as the temperature is raised. The low-temperature compressibility increases by 6% due to zero-point motion. Special emphasis is placed on atomic vibrations in the out-of-plane direction. Quantum effects are present in these vibrational modes, but classical thermal motion becomes dominant over quantum delocalization for large system size. The significance of anharmonicities in this atomic motion is estimated by comparing with a harmonic approximation for the vibrational modes in graphene bilayers. [ABSTRACT FROM AUTHOR]

This paper presents a simple method for determining the pretilt angle and cell thickness simultaneously, which are critical factors in liquid crystal displays. Their determination was achieved from the incident angles, where the transmittance was the same for each cell rotation with crossed polarizers and parallel polarizers, based on the crystal rotation method. Unlike the conventional crystal rotation method, which has a limited measurement range, the proposed method could cover all ranges of pretilt angles. [ABSTRACT FROM AUTHOR]

An inverse four-domain twisted nematic (IFDTN) liquid crystal (LC) display was fabricated by enhancing the azimuthal anchoring energy of the alignment layers. By stacking a vertical alignment layer onto a planar alignment layer, we increased the azimuthal anchoring energy by approximately 17-fold times compared to that with vertical alignment only. Due to the enhanced azimuthal anchoring energy, we were able to achieve a four-domain twisted nematic LC structure without dopant via the application of an external voltage. A simulation of the LC molecular orientation with respect to the azimuthal anchoring energy, the viewing angle characteristics, and the switching behavior of the IFDTN LC are presented. [ABSTRACT FROM AUTHOR]

A methodology to evaluate the emission characteristics of carbon nanotube layers in the context of liquid crystal display backlighting has been elaborated. Carbon nanotube layers with emission characteristics compatible with backlighting have been demonstrated for growth temperature as low as 400 °C, thanks to the use of plasma pretreatment before growth. This very low growth temperature allows to use soda lime glass for the backlight unit and thus to expect very low cost and very low power consumption devices with this technology. [ABSTRACT FROM AUTHOR]

The optical modulation properties of twisted-nematic liquid-crystal display (TN-LCD) can be totally predicted and optimized when its Jones matrix is known. An improved method for determining the Jones matrix of the TN-LCD without knowing its internal parameters is presented in this paper. Only three sets of intensity measurements are needed for the complete determination of the TN-LCD’s Jones matrix for a single wavelength, much less than the procedure offered by Moreno et al. This method is easier and stable in data processing and capable of diminishing the calculation error resulting from the fluctuation of intensity measurement effectively. The validity of this method is verified experimentally, whose results coincide well with the optical modulation properties of the TN-LCD predicted by our determined Jones matrix. [ABSTRACT FROM AUTHOR]

An optical shutter based on charged particles is presented. The output light intensity of the proposed device has an intrinsic dependence on the interparticle spacing between charged particles, which can be controlled by varying voltages applied to the control electrodes. The interparticle spacing between charged particles can be varied continuously and this opens up the possibility of particle based displays with continuous grayscale. [ABSTRACT FROM AUTHOR]

Various kinds of flat panel displays such as liquid crystal displays (LCDs), plasma display panels and organic light emitting diode (OLED) displays are briefly evaluated from the perspective of applicability to ubiquitous products. It is clarified that the LCDs and OLED displays are suitable for realizing mobile electronic products with a high quality display, since these displays can use active devices on the backplanes to form active matrix displays and can integrate peripheral circuits of the displays and functional circuits of mobile electronics for a ubiquitous era. It is clarified further that the low temperature polycrystalline silicon (LTPS) thin film transistor (TFT) is the most promising active device for the backplane of such active matrix displays because the LTPS TFT has the possibility to enhance its performance without raising the cost. The low temperature poly-Si TFT fabrication process is introduced, and its key technologies such as crystallization, gate oxide formation, and impurity doping are surveyed. As the property of polycrystalline silicon (poly-Si) influences not only the TFT performance itself but also the efficiency of impurity doping and the integrity of the gate oxide, the crystallinity of the poly-Si is reviewed. After that, the history of the development and the state of the art in impurity doping technology and its issues are addressed in detail. Finally, foreseeing the application of LTPS TFT, the realization of OLED displays, and the progress of LTPS TFT for integrating higher functional circuits for ubiquitous applications, the requirements for impurity doping in such progress are addressed. In particular, the single grain silicon technology and the scaling down of the TFT size, which are thought to be highly effective to enhance the performance of TFTs, and issues of impurity doping technology relating to them are discussed. [ABSTRACT FROM AUTHOR]

The discharge characteristics of plasma display panel with coplanar and counter-type electrode configurations are compared using the numerical modeling and experiment with respect to real and macrocells, respectively. Numerical analysis shows that the ultraviolet (UV) efficiency and driving voltage of counter type at a gap distance of 230 μm are located at similar levels to those of coplanar type at a gap distance of 60 μm. The UV efficiency for counter type is enhanced with the rise of xenon fraction and gap distance, between which the large gap operation is more advantageous to high UV efficiency. The measured temporal evolution of infrared emission reveals that the cathode layer plays an important role in forming the discharge current after the gas breakdown. It is found from the time-averaged visible and infrared emissions for the counter type that as the gap distance becomes larger, the positive column region increases but the sheath regime remains almost unchanged. On the other hand, the variation of gap distance gives a little influence on the average discharge current at the same applied voltage. The UV efficiency is thus greatly improved with the gap distance. When the gap becomes double, the UV efficiency is improved by 75%, which is well agreed with the results predicted in the numerical modeling. [ABSTRACT FROM AUTHOR]

This paper employs the molecular-dynamics method to generate random-dot patterns for light guides designed for backlight systems. The proposed approach combines various numerical techniques and is designed to optimize the dot-density distribution in order to satisfy the uniform luminance requirements demanded by liquid-crystal displays. In the proposed algorithm, the total domain is divided into a prescribed number of cells whose dot densities can be individually adjusted in order to fine tune the luminance conditions in accordance with the light source position and type. In addition, a variable truncation distance is implemented in each cell according to the dot density of that cell. This variable r-cut technique localizes the repulsive force effects acting within each cell in order that a high-dot-density gradient can be achieved in the overall dot distribution. Finally, an average force control technique is developed to ensure the uniformity of the dot distribution as it passes across the cell boundaries. Several illustrative examples are provided to demonstrate the robustness of the proposed molecular-dynamics dot-generation algorithm. [ABSTRACT FROM AUTHOR]

In this study, a plasma display panel (PDP) cell is modeled in a two-dimensional cross-sectional region and plasma discharge characteristics are analyzed by numerical simulations based on the finite difference method developed here. An orthogonal curvilinear coordinate system is introduced to apply to the arbitrary PDP cell geometry for systematic computations. Wall voltage transfer curves derived through experiments and computation are compared in detail. They show good agreement. The effect of PDP cell geometry on the voltage margin and on ultraviolet (UV) photon production efficiency are also studied. Results show that the thickness of front dielectric layer has a marked effect on the voltage margin and UV photon production efficiency. Furthermore, the dielectric ribs prevent the crosstalk of discharge in two ways: they decrease a number of excited species leaking to adjacent PDP cells and decrease charge distribution on the dielectric surface near the cell boundaries. [ABSTRACT FROM AUTHOR]

We have investigated how bus electrodes affect discharge and luminous characteristics of a discharge cell. Three-dimensional simulations have been performed in a coplanar structured alternating current plasma display panel cell, with phosphor saturation effect taken into account. There exists the optimal position of bus electrodes for high luminance and luminous efficiency. Considering bus electrode thickness, we have found that in-bus structure is a promising candidate for high luminance, high luminous efficiency, and fast operation plasma display panels. Our simulation results would be very useful to understand the influence of bus electrode on characteristics of a plasma display panel cell, and would also provide a general guidance to improve its display performances. [ABSTRACT FROM AUTHOR]

Optical transmittance of a 90-twisted nematic liquid crystal cell inserted between crossed or parallel polarizers is neither sensitive to the molecular twist sense nor to the exchange between the extraordinary and the ordinary birefringence axis at the input face of the cell. In this article, the equivalence between a twisted-nematic liquid crystal cell and the combination of a retardation wave plate and a polarization rotator is fully exploited to understand the physical origin of these ambiguities. We determine, in a simple way, cell parameters by means of standard cell transmittance measurements when both crossed and parallel polarizers are rotated simultaneously. We show that this procedure, which is subjected to the aforementioned ambiguities, can be completed by additional polarimetric measurements. In particular, we demonstrate that the twist angle, twist sense, retardation, and the rubbing direction can be univocally determined by experimental measurement of the Stokes parameters of the light transmitted through the cell at one wavelength. Laboratory results corresponding to a commercial liquid crystal display panel are carried out. [ABSTRACT FROM AUTHOR]

This article presents a front panel structure for an alternating current plasma display panel (AC-PDP) based on a ridged transparent dielectric layer and long hollow gap between the sustain electrodes. The suggested structure can reduce a firing voltage and sustain voltage than a conventional AC-PDP due to a strong electric field between the sustain electrodes. Experiments were conducted with various Xe contents from 10% to 50% at a gas pressure of 450 Torr, and the results confirmed that the ridged dielectric structure reduce the firing and sustain voltages by about 74 and 79 V at 10% Xe content than a conventional structure with 10% Xe content, respectively. Also, the proposed structure improve the luminous efficiency and luminance by about 50.9% and 33%, respectively, with a 50% Xe content when compared to a conventional structure with a 10% Xe content at a similar driving voltage. [ABSTRACT FROM AUTHOR]

The switch-off dynamics of a 180° supertwisted nematic (STN) are explored in detail by using a convergent beam system and the fully leaky guided-mode technique. From the dynamical guided-mode data and using the Ericksen–Leslie theory, the director structure in the cell at different times during switch-off is obtained. We have studied the dynamic switch-off from different applied voltages and have found that the relaxation time is independent of the voltage. From fitting the optical data, the effective viscosities are obtained. It appears that two viscosity coefficients, γ and η1, largely control the dynamics of switch-off. From the analysis of the director tilt profile in the cell, it is found that there is no backflow-induced increased tilt at the cell center in the STN cell during the switch-off. From liquid crystal hydrodynamics, this no-backflow dynamic process in the STN cell is well explained. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Reports on liquid crystals used in electronic displays which usually contain small amounts of ions that move under the influence of the varying applied electric field. Modified electric fields resulting in image sticking effects from the motion of ions perpendicular to the substrates; Image sticking effects near the pixel edge observed in supertwisted nematic cells.

We investigate the performance of several nonstandard plasma display panel cell geometry designs involving two-dimensional variations of the standard coplanar-electrode design. A cell design with a modified shape of sustain electrodes is found to have ~20% larger visible light generation efficiency without substantial increase of the operating voltages. Similar performance improvement is achieved by designs with different shapes of the upper dielectric, or by those involving two different dielectric layers. The dependence of cell performance on the design parameters of these structures is investigated. [ABSTRACT FROM AUTHOR]

In order to understand the discharge characteristics in an alternating current plasma display panel (ac PDP) and optimize it further, a three-dimensional fluid code (FL3P) has been developed. Using this simulator, various three-dimensional features of discharges are investigated in the sustain mode of PDP. First, the striations of wall charge are observed at both the anode and cathode side. Second, the local efficiency is obtained as a function of position. It is mainly divided into the anode region and the cathode region and highest near the anode center. Finally, the effects of various three-dimensional parameters are studied. As one of the examples showing the effect of electrode shaping, the discharge characteristics of a T-shaped electrode cell are compared with those of a conventional cell. The phosphor on barrier ribs contributes to over 44% of the total luminance, but barrier ribs themselves do not play an important role in the overall discharge efficiency. Address electrode width is not always proportional to the size of the discharge because of the wall loss of the particles to barrier ribs. [ABSTRACT FROM AUTHOR]

A two-dimensional self-consistent simulation model is used to study the effect of the geometric parameters on the operating voltages and ultraviolet (UV) efficiency of a coplanar-electrode plasma display panel cell. It is found that in the standard coplanar-electrode geometry there is a tradeoff between high UV efficiency and low operating voltages as the electrode gap, or the parameters of the upper dielectric are varied, while variation of the sustain electrode width has no significant effect on either the operating voltages or UV efficiency. It is also found that wider discharge area results in higher efficiency. In addition, the effect of the insertion of floating electrodes in the upper dielectric is investigated. When floating electrodes are used, UV light is emitted in a more confined area, thus limiting cross talk with adjacent cells, while efficiency decreases by ∼8%. Finally, a self-erase discharge sustaining waveform is studied. Use of this waveform results in ∼17% increase in the efficiency. [ABSTRACT FROM AUTHOR]

A model for describing properties of a liquid crystal display which combines the concepts of in-plane switching and vertical alignment is proposed. There is good agreement between the results of this model and direct computer calculation of the director and the light transmittance. The usefulness of the model lies in the faster speed of calculations compared to direct computer solution of the Euler-Lagrange equations. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Low luminous efficacy is one of the major drawbacks of plasma display panels (PDPs), where the main limiting factor is the efficiency of the microdischarges in generating UV radiation. In this work we use a two-dimensional self-consistent fluid model to analyze the energy loss mechanisms in neon-xenon discharges in coplanar-electrode color PDPs and interpret experimental data on the luminous efficacy of these PDPs. The modeling results are in good agreement with the measured UV emission spectrum and measured trends in the efficacy. Most of the electrical input energy is transferred to ions and subsequently to the gas and the surface. The electrical energy transferred to electrons is mostly used for ionization and excitation, where the part used for xenon excitation largely ends up in UV radiation. The amplitude, frequency, and rise time of the driving voltage mainly affect the energy losses due to ion heating. The xenon content also affects the conversion of electron energy into UV energy. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the plasma evolution in dielectric barrier discharges occurring in a commercial ac plasma display panel (PDP) by using a macroscopic PDP discharge cell. Electrical characteristics; Current pulse shape; Paschen curves, voltage margin and MgO layer.

Discusses the origin and characteristics of the field-off state optical properties of general twisted nematic liquid-crystal displays (LCD). Modes of LCD; Optical working mechanism for the general twisted nematic LCD; Characteristics of the field-off state optical properties of the general twisted nematic displays.

This work, performed by means of time-resolved high-resolution birefringence measurements, establishes the switching mechanism of electrically commanded surfaces (ECS) for liquid-crystal displays. A distinct polar electro-optic response, due to the field-induced in-plane switching of the molecules of the 200-nm ferroelectric liquid crystalline polysiloxane alignment layer representing ECS, was detected in a cell filled with isotropic liquid (hexadecane). The similarity between this response and the one reported recently in cells containing the same ECS but with a nematic liquid-crystal bulk with negative dielectric anisotropy (Δ[variant_greek_epsilon]<0) and field-free planar alignment provides direct and unambiguous proof that the switching in these cells is indeed mediated by the ECS. [ABSTRACT FROM AUTHOR]

Provides information on a study which determined the effects of helium plasma emission on the characteristics of the visible emission from a surface-type alternate current plasma display panel. Descriptions of a plasma display panel; Details on the experiment; Results and discussion.

Auditory display can complement visual representations in order to better interpret scientific data. A previous article showed that the free categorization of "audified seismic signals" operated by listeners can be explained by various geophysical parameters. The present article confirms this result and shows that cognitive representations of listeners can be used as heuristics for the characterization of seismic signals. Free sorting tests are conducted with audified seismic signals, with the earthquake/seismometer relative location, playback audification speed, and earthquake magnitude as controlled variables. The analysis is built on partitions (categories) and verbal comments (categorization criteria). Participants from different backgrounds (acousticians or geoscientists) are contrasted in order to investigate the role of the participants' expertise. Sounds resulting from different earthquake/station distances or azimuths, crustal structure and topography along the path of the seismic wave, earthquake magnitude, are found to (a) be sorted into different categories, (b) elicit different verbal descriptions mainly focused on the perceived number of events, frequency content, and background noise level. Building on these perceptual results, acoustic descriptors are computed and geophysical interpretations are proposed in order to match the verbal descriptions. Another result is the robustness of the categories with respect to the audification speed factor. [ABSTRACT FROM AUTHOR]

We demonstrate electrical tuning of the spectral response of a Mie-resonant dielectric metasurface consisting of silicon nanodisks embedded into liquid crystals. We use the reorientation of nematic liquid crystals in a moderate applied electric field to alter the anisotropic permittivity tensor around the metasurface. By switching a control voltage "on" and "off," we induce a large spectral shift of the metasurface resonances, resulting in an absolute transmission modulation of up to 75%. Our experimental demonstration of voltage control of dielectric metasurfaces paves the way for new types of electrically tunable metadevices, including dynamic displays and holograms. [ABSTRACT FROM AUTHOR]

In the previous work, we reported that the luminous efficacy was significantly improved using the short sustain pulse width with sufficiently long off-time between sustain pulses. In this paper, we have proposed the dual sustain pulse as an alternative of short sustain pulse width when the off-time is short. We demonstrate that the luminous efficacy can be significantly improved by using the new dual sustain waveform, which is attribute to the effects of the dual sustain pulse as well as short sustain pulse width when the off-time is 1μs. The proper adjustment of the 1st sustain discharge can induce the 2nd sustain discharge out of the sustain pulse, resulting in the high luminous efficacy. Comparing to the luminous efficacy of the conventional case, it is improved by approximately 130% due to the effects of dual sustain pulse as well as short sustain pulse width. [ABSTRACT FROM AUTHOR]

A detailed analysis, based on kinetic and fluid simulations, of striation phenomenon in the plasma display panel cell has been presented. Numerical studies indicate that the phenomenon of striation occurs primarily due to the accumulation of space charge near the anode electrode. These space charges locally create multiple-layer potential distribution near the anode region. The ion density in the vicinity of this region groups up due to ionization processes, which are caused by electron species. However, the electrons are further attracted by the anode. Well-like deformations occur in the anode potential distribution, which confine electrons and produce density humps. On the contrary, cathode plasma density depends on the secondary-electron emission by ions that are attracted to the anode dielectric surface. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Reports on the development of a data acquisition and display system for the study of electron impact ionization of atoms. System details; Time walk in coincidence data; Coincidence separation energy measurements; Coincidence Auger data.

A low-cost, high-performance image acquisition and display system for scanning tunneling microscopy, based on a PC/AT compatible computer and a video frame grabber is described. The imaging system allows the use of fast scan rates and provides for viewing of the image as it is acquired. The imaging system could be used in any application involving single frame image acquisition at a rate at or below the standard video rate of 30 s-1. [ABSTRACT FROM AUTHOR]

We report the realization and properties of a high-resolution solid-state self-emissive microdisplay based on III-nitride semiconductor micro-size light emitting diodes (µLEDs) capable of delivering video graphics images. The luminance level of III-nitride microdisplays is several orders of magnitude higher than those of liquid crystal and organic-LED displays. The pixel emission intensity was almost constant over an operational temperature range from 100 to -100 °C. The outstanding performance is a direct attribute of III-nitride semiconductors. An energy efficient active drive scheme is accomplished by hybrid integration between µLED arrays and Si CMOS (complementary metal-oxide-semiconductor) active matrix integrated circuits. These integrated devices could play important roles in emerging fields such as biophotonics and optogenetics, as well as ultra-portable products such as next generation pico-projectors. [ABSTRACT FROM AUTHOR]

A low voltage (<10 V) and high transmittance (∼85.6%) polymer-stabilized blue-phase liquid crystal (BPLC) display is proposed. The periodic corrugated electrodes generate a strong horizontal field component to induce isotropic-to-anisotropic transition in the BPLC medium through Kerr effect. Moreover, this field is uniformly distributed across the entire LC layer so that the accumulated phase retardation along the beam path is large, resulting in low voltage and high transmittance. This approach enables BPLC to be addressed by amorphous-silicon thin film transistors, which would accelerate its emergence as next-wave display technology. [ABSTRACT FROM AUTHOR]

This letter demonstrates the feasibility of producing variable liquid crystal (LC) pretilt angles using light-induced ripple structures (LIRSs) in homeotropically aligned azo dye-doped liquid crystals (ADDLCs). Illuminating homeotropically aligned ADDLCs with a linearly polarized light for a suitable period yields the LIRSs which provide LCs an anisotropic homogeneous anchoring force. Experimentally, the effective alignment force produced by the homeotropic alignment layer and the LIRSs determines the LC pretilt angle (24° to 63.5°), defined from the normal to the substrate. A no-bias pi cell for liquid crystal displays is demonstrated using this approach. [ABSTRACT FROM AUTHOR]

Improvement in the luminescent properties of plasma display panels via phosphor size control was theoretically and experimentally investigated. From theoretical analyses of photon extraction and plasma efficiency, fine phosphor system was designed, which was compared with experimental data. The denser microstructure of finer phosphor-based layer promoted photon extraction efficiency by higher reflectivity. Also, the finer phosphor increased vacuum-ultraviolet discharge space and corresponding plasma efficiency via decrease in layer thickness. Based on the results, the phosphor size control improved the panel efficiency by the synergistic effect of improvements in photon extraction and plasma efficiency. [ABSTRACT FROM AUTHOR]

A wide-view transflective liquid crystal display (TR-LCD) using a single cell gap multidomain vertical alignment (MVA) cell is proposed. Unlike a conventional MVA which uses physical protrusions to form multidomain structures, our TR-LCD uses slit-induced longitudinal and fringe electric fields to generate multidomains. As a result, wide-view, high contrast ratio, and high transmittance are obtained. By varying the slit density in the transmissive and reflective regions, the optical path-length disparity between these regions can be balanced. Potential application of this TR-LCD for mobile displays is emphasized. [ABSTRACT FROM AUTHOR]

A fringe-field-switching (FFS) liquid crystal display (LCD) using a thin cell doped with a reverse-handed chiral compound is proposed. Such a FFS LCD exhibits a fast response time (∼8 ms), high transmittance (>90%), low operating voltage (5 Vrms), and intrinsically wide viewing angle. Its application for LCD televisions in order to reduce image blurring is emphasized. [ABSTRACT FROM AUTHOR]

The authors fabricated a no-bias pi cell using a dual alignment layer with an intermediate pretilt angle via a rubbing. In the dual alignment layer system, the competition between crest region favoring the vertical alignment and trough region favoring planar alignment made it possible to achieve various pretilt angles, and adjusted pretilt angle from 90° to 20° with rubbing. In addition, as the intermediate pretilt angle plays a role in eliminating the activation energy and thus allowing formation of the initial bend state in pi cell fabrication, this approach achieved a no-bias pi cell for a liquid crystal display with both low power consumption and fast response. [ABSTRACT FROM AUTHOR]

A compensation method that uses uniaxial films is developed for widening the viewing angle of the high-transmittance multidomain vertical-alignment liquid crystal display (MVA-LCD). Based on this design, the high-transmittance MVA-LCD is predicted to have a complete 80° viewing cone for contrast ratio (CR)>100:1. Experimental results indicate that the real high-transmittance MVA-LCD panel has a viewing angle more than the entire 80° viewing cone for CR>30:1. Potential application as a mobile display is emphasized. [ABSTRACT FROM AUTHOR]

The authors report on an alignment layerless (AL) flexible liquid crystal (LC) display fabricated at ambient temperature through an imprinting process. One-dimensional microgrooves and two-dimensional arrays of microstructures embossed on plastic substrates provide the spontaneous alignment of the LC molecules and spacers for the uniform cell gap in a flexible LC display, respectively. It is found that the azimuthal anchoring energy, generated from the microgrooves, is on the order of 10-5 J/m2 which is strong enough to uniformly align the LC over large area. Our AL flexible LC display shows symmetric viewing characteristics and stable electro-optic properties under a bent environment. [ABSTRACT FROM AUTHOR]

An ink-jet print head in a structure, similar to a liquid crystal display, is suggested. It is based on a segment, containing a microink reservoir, feeding one or a few nozzles. The segment is autonomous and unlimitedly duplicable to form a large ink-jet print head. The microreservoirs are open to the atmospheric pressure, and pressure regulation in the nozzle is accomplished by capillary action. The microreservoirs are replenished by slow wiper smearing action. Experiments with a 57600 nozzle matrix print head showed good results for the design. Printing speed of ∼1000 pagesmin, and even more, is achievable. [ABSTRACT FROM AUTHOR]

Twist angle effects on the response time of in-plane-switching liquid crystal displays are analyzed. The authors propose a device configuration whose top and bottom boundary liquid crystal layers are symmetric to each other with respect to the electric field direction. The analytical results of this device configuration indicate that the response time is improved at least four times faster than that of a conventional in-plane-switching twisted-nematic mode and normal in-plane-switching mode. [ABSTRACT FROM AUTHOR]

We developed a composite system to produce robust bistable smectic-A (SmA) liquid crystal based flexible displays by encapsulating the liquid crystal material in a polymer wall structure. While keeping all the intrinsic bistable properties of the SmA material, the field-induced polymer walls bridge the two display substrates and bring significant advantages over the polymer dispersed liquid crystal structure. Here we analyze the performance of an encapsulated pixel and demonstrate superior electro-optical characteristics, high contrast ratio, and excellent sunlight readability. [ABSTRACT FROM AUTHOR]

We describe a directed vertical alignment (VA) display mode based on a nematic liquid crystal (LC) doped with a chiral dopant and confined between two substrates, one of which is pretreated, say, by unidirectional rubbing or photoalignment. The design allows one to eliminate umbilical defects that appear during switching of the conventional VA cells and thus to obtain better contrast. Switching is ∼30% faster than for VA cells when optimized concentration of a chiral dopant is added and LC molecules at one of the substrates are slightly tilted from the cell normal due to the unidirectional surface treatment. [ABSTRACT FROM AUTHOR]