Application Of Display Technology Research Articles

Design, manufacturing and experimental validation of a bonded dual-component microstructured system for vertical light emission

This article presents a bonded dual-component microstructured planar device made of acrylic glass for vertical light emission. It features optical, cone-like undercut microstructures for efficient illumination from a light guiding plate. This microstructured light guide is designed with the help of numerical raytracing simulations for the use as an innovative luminaire for room lighting. It can also find application in display technology for efficient backlight units. To realize such undercut microstructures in acrylic glass, a variothermal injection molding process, complemented by an ultraviolet radiation assisted thermal bonding procedure is introduced. By modifying the glass transition temperature of a thin surface layer of the microstructures the undercut microstructures can be bonded thermally to a light guiding plate without any glue or solvent, while the shape of the microstructures is perfectly preserved. Measurements verify the high bonding quality and confirm the good correspondence between measured light emission and ideal optical simulations.

Application of Display Technologies for Lighting

The article is devoted to contemporary overview of development of a number of display technologies, which have been applied or may be applied for creation of new prospective light engineering solutions. The emphasis is on OLED-based technologies and liquid crystalsbased technologies. Examples of their application in automotive industry and architecture are given with consideration of various economic indicators and hygienic and usability limitations.

Demonstration of α-InGaZnO TFT Nonvolatile Memory Using TiAlO Charge Trapping Layer

Amorphous indium gallium zinc oxide (α-InGaZnO) thin-film transistors using as nonvolatile memories (TFT-NVMs) with an Al2O3/TiAlO/Al2O3 charge trapping engineered structure have been demonstrated experimentally at low thermal budget of 300 °C. The high- k composite TiAlO layer with a high trap state density and a high dielectric constant was prepared by sputtering at room temperature as a charge trapping material. According to the high-resolution transmission electron microscopy analyses, the Al2O3/TiAlO/Al2O3 gate stack exhibited sharp interfaces and a uniform distribution of Ti and Al elements in the TiAlO film. The programming and retention characteristics of the fabricated α-InGaZnO TFT-NVMs were investigated in detail. The TFT-NVMs exhibited excellent programming characteristics with a large memory window of around 5.74 V under a 16 V programming voltage. It can also maintain a memory margin of about 5 V after 10 years, indicating only ∼15% charge loss. This paper suggests that α-InGaZnO TFT-NVMs using the high- k TiAlO composite material as the charge trapping material are promising for future nonvolatile memories applications in display technology, flexible and wearable electronics.

34.1: Invited Paper: Application of Display technology in Automobile

In this paper, the application scene of TN / HTN / YA and TFT‐LCD liquid crystal display technology in automobile is described, including the application of onboard instrument, multimedia, navigator and automobile auxiliary device, and the application of microdisplay LED technology in automobile's head up display. The development trend of auto display and the prospect of LCD technology in automobile are introduced.

Colloidal Synthesis of Air-Stable CH3NH3PbI3 Quantum Dots by Gaining Chemical Insight into the Solvent Effects

Because of the superior optical properties and potential applications in display technology, colloidal synthesis of halide perovskite quantum dots has been intensively studied. Although great successes have been made in the fabrication of green emissive CH3NH3PbBr3 quantum dots, the fabrication of stable iodide-based CH3NH3PbI3 quantum dots remains a great challenge because of their sensitivity to moisture in the open air. Even in a glovebox, the colloidal CH3NH3PbI3 quantum dots obtained from N,N-dimethylformamide suffer from instability caused by fast degradation within days to weeks. In this work, we investigated the interactions between perovskite precursors and various polar solvents as well as their influence on the crystallization of CH3NH3PbI3 in reprecipitation synthesis. By gaining chemical insight into the coordination effects, we can explain the degradation of CH3NH3PbI3 to the defective crystals with coordinated solvents on the surface and/or intrinsic inner iodine vacancies. On the basis of ...

Solid State Electrochemical WO3 Transistors with High Current Modulation

In this paper, the role of electrode architecture (conventional and interdigital), device structure (vertical or planar), and tungsten oxide (WO3) channel thickness on the electro‐optical performances of room temperature sputtered electrochromic transistors (EC‐Ts) is reported. A larger number of electro‐reducible tungsten sites in thicker WO3 films provide improved optical density and coloration efficiency. However, overall transistor performance is found to suffer in planar EC‐Ts with the conventional electrode architecture, where the step to planar interdigital electrodes leaves the devices to be almost insensitive to WO3 thickness. Vertical structures result in improved device properties and stability, given to the shorter distance between gate electrode and semiconductor and to the encapsulation effect provided by such structures. These devices show an On–Off ratio of 5 × 106 and a transconductance (g m) of 3.59 mS, for gate voltages (V G) between −2 and 2 V, which to the authors' knowledge are the best values ever reported for electrochemical transistors. The simple and low‐cost processing together with the electrical/optical performances well supported into a comprehensive analysis of device physics opens doors for a wide range of new applications in display technologies, biosensors, fuel cells, or electrochemical logic circuits.

Energy transfer, tunable emission and optical thermometry in Tb3+/Eu3+ co-doped transparent NaCaPO4 glass ceramics

Tb3+/Eu3+ co-doped glass ceramics containing NaCaPO4 nanocrystals were successfully synthesized via traditional melt-quenching route with further heat-treatment and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence spectroscopy. The energy transfer process of Tb3+→Eu3+ was confirmed by excitation and emission spectra and luminescence decay curves, and the energy transfer efficiency was also estimated. The results indicated that the efficient emission of Eu3+ was sensitized by Tb3+ under the excitation of 378nm, realizing tunable emission in the transparent bulk glass ceramics containing NaCaPO4 nanocrystals. Furthermore, optical thermometry was achieved by the fluorescence intensity ratio between Tb3+:5D4→7F5 (~542nm) and Eu3+:5D0→7F2 (~612nm). The maximum absolute sensitivity of 4.55% K−1 at 293K and the maximal relative sensitivity of 0.66% K−1 at T=573K for Tb3+/Eu3+ co-doped transparent NaCaPO4 glass ceramic are obtained. It is expected that the investigated transparent NaCaPO4 glass ceramics doped with Tb3+/Eu3+ have prospective applications in display technology and optical thermometry.

Alkaline Earth Metal Zirconate Perovskites MZrO3 (M=Ba(2+), Sr(2+), Ca(2+)) Derived from Molecular Precursors and Doped with Eu(3+) Ions.

The effect of alkaline earth metal alkoxides on the protonation of zirconocene dichloride was investigated. This approach enabled the design of compounds with preset molecular structures for generating high-purity binary metal oxide perovskites MZrO3 (M=Ba(2+), Sr(2+), Ca(2+)). Single-source molecular precursors [Ba4 Zr2 (μ6 -O)(μ3 ,η(2)-OR)8 (OR)2(η(2) -HOR)2 (HOR)2 Cl4], [Sr4 Zr2 (μ6 -O)(μ3 ,η(2)-OR)8 (OR)2 (HOR)4 Cl4], [Ca4 Zr2 (μ6-O)(μ3 ,η(2)-OR)8 (OR)2 Cl4], and [Ca6 Zr2 (μ2 ,η(2)-OR)12 (μ-Cl)2 (η(2) -HOR)4 Cl6 ]⋅8 CH2 Cl2 were prepared via elimination of the cyclopentadienyl ring from Cp2 ZrCl2 as CpH in the presence of M(OR)2 and alcohol ROH (ROH=CH3OCH2 CH2OH) as a source of protons. The resulting complexes were characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray diffraction. The compounds were then thermally decomposed to MCl2 /MZrO3 mixtures. Leaching of MCl2 from the raw powder with deionized water produced highly pure perovskite-like oxide particles of 40-80 nm in size. Luminescence studies on Eu(3+)-doped MZrO3 revealed that the perovskites are attractive host lattices for potential applications in display technology.

Efficient sensitization of Tb3+ emission by Dy3+ in CaMoO4 phosphors: Energy transfer, tunable emission and optical thermometry

Dy3+/Tb3+ codoped CaMoO4 phosphors were synthesized by a simple sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy. The energy transfer process of Dy3+→Tb3+ was confirmed by excitation and emission spectra and luminescence decay curves, and the energy transfer efficiency was also estimated. The results verified that the efficient emission of Tb3+ was sensitized by Dy3+ under the excitation of 354nm, realizing tunable emission in CaMoO4 phosphors. Furthermore, optical thermometry was achieved by the fluorescence intensity ratio between Tb3+: 5D4→7F5 (~546nm) and Dy3+: 4F9/2→6H13/2 (~575nm). It is expected that the investigated CaMoO4 nanograins doped with Dy3+/Tb3+ have prospective applications in display technology and optical thermometry.

The electronic, optical, and thermodynamic properties of borophene from first-principles calculations

Borophene shows highly anisotropic metallic behaviour (a) due to anisotropic structure (b). The optical properties of borophene are orientation-dependent (c). This provides opportunities for applications in display technologies, photovoltaics and flexible electronics.

Importance of Organic Synthesis in the Development of Liquid Crystals

Liquid crystals are fascinating materials in many areas of applied science. They are widely known for their application in display technology and uses in other fields have also recently been identified, such as anisotropic networks, organic light-emitting diodes and photo- and semiconducting materials. Further applications in new areas continue to be developed, as well as effective solutions to problems associated with the limitations of liquid crystals. Designing novel thermotropic liquid crystals for applications in advanced functional materials involves the selection of a suitable central core, linking group and terminal functionality. Over the years, a very large number of heterocyclic compounds containing liquid crystal units have been synthesized. Interest in this field of research has increased considerably in recent years due to improvements in synthetic methodologies. This critical mini-review describes some basic design principles and synthetic approaches to prepare the most commonly found liquid crystals, especially fivemembered nitrogen heterocycles, such as 1,2,4- and 1,3,4-oxadiazols, isoxazole, 1,2,3-triazole, 1,3,4-thiadiazole, 1,3-thiazole and 2,1,3- benzothiadiazole. Keywords: 1, 3-Dipolar Cycloaddition, Click chemistry, Liquid Crystals, N-heterocycles, Organic Synthesis, Sonogashira Cross-coupling.

Image-contrast technology based on the electrochemiluminescence of porous silicon and its application in fingerprint visualization.

The electrochemiluminescence (ECL) of porous silicon (pSi) has attracted great interest for its potential application in display technology and chemical sensors. In this study, we found that pSi with a different surface chemistry displayed an apparently different dynamic ECL process. An image-contrast technology was established on the basis of the intrinsic mechanism of the ECL dynamic process. As a proof of principle, the visualization of latent fingerprints (LFPs) and in situ detection of TNT in fingerprints was demonstrated by using the ECL-based image-contrast technology.

Image‐Contrast Technology Based on the Electrochemiluminescence of Porous Silicon and Its Application in Fingerprint Visualization

AbstractThe electrochemiluminescence (ECL) of porous silicon (pSi) has attracted great interest for its potential application in display technology and chemical sensors. In this study, we found that pSi with a different surface chemistry displayed an apparently different dynamic ECL process. An image‐contrast technology was established on the basis of the intrinsic mechanism of the ECL dynamic process. As a proof of principle, the visualization of latent fingerprints (LFPs) and in situ detection of TNT in fingerprints was demonstrated by using the ECL‐based image‐contrast technology.

Laser induced electro-optical characterization of anthraquinone dye and fullerene C60 doped guest-host liquid crystal systems

Liquid crystals have become the focus of great interest in recent years particularly with applications in display technology. Guest-host liquid crystal displays (GH-LCDs) are widely utilized because of their many advantages such as color, wide viewing angle and high brightness. The aim of this study is to determine the electro-optical properties of disperse orange 11 dye and fullerene C60 doped GH-LCDs. A 40mW He–Cd (λ=441.6nm) laser was used as a pumping source during the measurements, which were carried out by an impedance analyzer to observe the effect of laser illumination on the samples. Dielectric anisotropy was quantitatively estimated by using capacitive measurements and estimated as positive for all samples. Photoconductivity of the samples was defined under dark and illuminated conditions. Experimental results also indicate that laser pumping has a considerable effect on the photoconductivity.

A novel generation of photoactive comb-shaped polyamides for the photoalignment of liquid crystals

A new approach to the synthesis of photoactive comb-shaped homo- and copolyamides containing azobenzene, cinnamate, and coumarin side groups for photoalignment of liquid crystals was elaborated. Photooptical properties and photoorientational ability of these polymers with respect to liquid crystals were studied. It was shown that polarized UV irradiation of all spin-coated polyamides leads to orientation of liquid crystalline molecules deposited on the polyamide thin films. The synthesized polymers containing cinnamate and coumarin side groups as well as azobenzene-containing cyano- and nitro-substituted polymers demonstrated good orientation ability in relation to liquid crystals displaying photoinduced planar orientation with high dichroism values within the range of 0.68–0.72. Contrary to the above-mentioned polyamides, azobenzene-containing fluorosubstituted polymers induced a homeotropic orientation of liquid crystals. It was shown that the synthesized photoactive polyamides can be considered as promising photoalignment materials for application in display technology, photonics, and other “smart” optical devices. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4031–4041

Titanyl phthalocyanines: Electrochemical and spectroelectrochemical characterizations and electrochemical metal ion sensor applications of Langmuir films

Electrochemical and spectroelectrochemical characterizations of titanyl phthalocyanines, which were peripheral (α-TiOPc) and nonperipheral (β-TiOPc) tetra and octa substituted (octa-TiOPc) with 3,4-(methylendioxy)-phenoxy moieties were performed to determine their possible applications in different electrochemical technologies. Voltammetric and in situ spectroelectrochemical measurements illustrate that position and number of 3,4-(methylendioxy)-phenoxy substituents affect the redox behavior of the complexes. While α-TiOPc gives up to four reduction processes, β-TiOPc and octa-TiOPc gives up to three reduction processes. While octa-TiOPc gives metal–metal–ring–ring reductions, α-TiOPc and β-TiOPc complexes give metal–ring–ring–metal reduction mechanism. Solvent of the media also alter the electrochemical behavior of the complexes. In situ electrocolorimetric measurements shows distinct color differences among the electrogenerated anionic and cationic redox species, which indicates their possible applications in display technologies. Multiple and reversible, diffusion controlled and multi-electron redox reaction indicate possible usage of the complexes especially in electrosensing applications. The complexes sense Ag+ and Pd2+ ions in the solution and in the solid states.

Synthesis of silver nanorods using Coscinium fenestratum extracts and its cytotoxic activity against Hep-2 cell line

Silver nanorod has attracted considerable interest due to its potential applications in display technologies, thermoelectric and electronic devices, optoelectronic devices and biomedicine. In this study, crystalline silver nanorods were successfully prepared from AgNO3 using Coscinium fenestratum extract as a reducing agent. The products were characterized by UV–visible spectroscopy, FTIR (Fourier-transform IR) spectroscopy and SEM (scanning electron microscopy) analysis. Bundle-like nanostructures were observed by SEM analysis and the diameters of the nanorods were found to be in the range of 28.5–68.0nm. The MTT assay results revealed that silver nanorod exhibit significant cytotoxic effect on HEp-2 cells.

Liquid crystals photoalignment by films of side-chain azobenzene-containing polymers with different molecular structure

Liquid crystals photoalignment on the films of several side-chain azobenzene-containing polymers with various molecular structures was studied. Kinetics of the alignment and realignment of the liquid crystals director under irradiation by the polarized light was investigated and a comparison of the rates of polymers’ azobenzene moieties reorientation and director realignment were performed. The degree of the orientation, stability of the alignment, the possibility of multiple reorientation and other parameters of the photoinduced processes occurring in polymers films and liquid crystal cells were studied in detail. A rubbing technique was applied as alternative method for LC-alignment using these azobenzene-containing polymers. It was shown that the studied azobenzene-containing polymers can be considered as a photocontrollable command surfaces for the application in display technology and optoelectronics.

High quality thin film phosphors of Y 2O 3:Eu 3+ deposited via chemical bath deposition

High transparency in visible region was required for red-light-emitting Y 2O 3:Eu 3+ thin film phosphors. Such films were obtained via chemical bath deposition on bare SiO 2 glass substrates through heterogeneous nucleation with further heat treatment. Thin amorphous yttrium basic carbonate films could be completely transformed to crystalline Y 2O 3 at 650 °C. X-ray diffraction and field-emission scanning electron microscopy were used to characterize these products. The deposition temperature and the post-annealing conditions were crucial factors for preparing high-quality thin films. The thin films prepared with optimized parameters emitted a bright red light around 612 nm. Meanwhile, these thin films exhibited optical transmittance of 90% to 95% in a wavelength range of 400 to 800 nm depending on the chemical deposition solution. These results clearly indicated that chemical solution deposition is a promising technique for large-scale production of thin film phosphors in application of display technology.

New high for quantum dot VECSELs

The first multi-watt quantum dot (QD) vertical external-cavity surface-emitting laser (VECSEL) operating at long wavelength and high power has been demonstrated by collaborative researchers from the Center for High Technology Materials at the University of New Mexico and the University of Arizona. This represents a significant step towards high power laser applications in display technology, telecommunications and circuits.