Application Of Display Technology Research Articles

Comparative computational analysis of orthoconic antiferroelectric liquid crystals: DFT analysis.

The study undertakes a comparative analysis of four distinct semi-fluorinated chiral Organic Active Ferroelectric Liquid Crystals (OAFLCs). The comparative analysis of the compounds is done by using various parameters, including thermodynamic, non-linear optical, electrical, atomic charge distribution, and atomic orientations. We use optimization algorithms to look at chemical reactivity, electrical properties, intermolecular interactions, and static hyperpolarizability. Sample 4 is the best choice for a wide range of display applications. This research contributes to understanding the nuanced properties of semi-fluorinated chiral OAFLCs and highlights Sample 4's potential for novel applications in display technology, owing to its superior stability and optimized properties. This study helps to enhance our understanding of the comparative analysis of semi-fluorinated chiral OAFLCs for potential advancements in display technologies by incorporating findings from key studies. The simulations are performed using density functional theory (DFT) with the B3LYP functional for predicting molecular properties, and Vibrational Energy Distribution Analysis (VEDA) software is used to perform the vibrational analysis of the molecules.

Exploration of red and deep red Thermally activated delayed fluorescence molecules constructed via intramolecular locking strategy

Red and deep red (DR) organic light-emitting diodes (OLEDs) have garnered increasing attention due to their widespread applications in display technology and lighting devices. However, most red OLEDs exhibit low luminescence efficiency, severely limiting their practical applications. To address this challenge, we theoretically design four novel TADF molecules with red and DR luminescence using intramolecular locking strategies building upon the experimental findings of DCN-DLB and DCN-DSP, and their crystal structures are predicted with the lower energy and higher packing density. The photophysical properties and luminescence mechanism of six molecules in toluene and crystal are clarified using the first principles calculation and thermal vibration correlation function (TVCF) method. The proposed design strategy is anticipated to offer several advantages: enhanced electron-donating capabilities, more rigid structures, longer emission wavelengths and higher luminescence efficiency. Specifically, we introduce oxygen atoms and nitrogen atoms as intramolecular locks, and the newly developed DCN-DBF and DCN-PHC have redshifted emission, narrow singlet–triplet energy gap (ΔEST), fast reverse intersystem crossing rate and enhanced photoluminescence quantum yield (PLQY). Notably, DCN-DBF achieves both long wavelength emission and high efficiency, with emission peaks at 598 nm and 587 nm corresponding to PLQY of 52.13 % and 43.42 % in toluene and crystal, respectively. Our work not only elucidates the relationship between molecular structures and photophysical properties, but also proposes feasible intramolecular locking design strategies and four promising red and DR TADF molecules, which could provide a valuable reference for the design of more efficient red and DR TADF emitters.

Electromagnetic Enantiomer: Chiral Nanophotonic Cavities for Inducing Chemical Asymmetry.

Chiral molecules, a cornerstone of chemical sciences with applications ranging from pharmaceuticals to molecular electronics, come in mirror-image pairs called enantiomers. However, their synthesis often requires complex control of their molecular geometry. We propose a strategy called "electromagnetic enantiomers" for inducing chirality in molecules located within engineered nanocavities using light, eliminating the need for intricate molecular design. This approach works by exploiting the strong coupling between a nonchiral molecule and a chiral mode within a nanocavity. We provide evidence for this strong coupling through angular emission patterns verified by numerical simulations and with complementary evidence provided by luminescence lifetime measurements. In simpler terms, our hypothesis suggests that chiral properties can be conveyed on to a molecule with a suitable chromophore by placing it within a specially designed chiral nanocavity that is significantly larger (hundreds of nanometers) than the molecule itself. To demonstrate this concept, we showcase an application in display technology, achieving efficient emission of circularly polarized light from a nonchiral molecule. The electromagnetic enantiomer concept offers a simpler approach to chiral control, potentially opening doors for asymmetric synthesis.

[formula omitted] leaves mediated combustion synthesis of Tb[formula omitted] doped Zn2V2O7 nanoparticles: Color tunable photoluminescence and electrochemical studies for display and supercapacitor applications

A new series of Tb3+ doped Zn2V2O7 (ZV) nanoparticles (NPs) at different concentration from 1 to 9 mol% was synthesized by Menthaspicata leaves extract mediated solution combustion method. On Tb3+ doping, the diffraction pattern matches well with the monoclinic crystal structure with the C2/c(2/m) space group of ZV host matrix. The surface morphology tuned from irregular shaped NPs to hexagonal shaped NPs with variation in dopant concentration. The crystallite size estimated from Scherrer’s method matches well with the transmission electron microscopy analysis. The optical band gap determined from Tauc’s plot utilizing UV–Visible absorption was tuned from 3.061 to 3.035 eV with increase in dopant concentration. Under 266 nm excitation, the emission of Tb3+ ions from Tb3+-doped ZV NPs is observed, with the intensity of emission showing sensitivity to the concentration of Tb3+ ions. The optimal doping content is determined to be 7 mol %. The CIE coordinates clearly indicates the tuning of the emission color from green to blue region with increase in dopant concentration. The average color coordinated temperature was found to be 7895 K showing the cooler appearance. Further, cyclic voltammetry analysis offers valuable insights into redox reactions, electrode kinetics, and overall electrochemical behavior, while Electrochemical Impedance Spectroscopy (EIS) provides information on ion transport kinetics. Galvanostatic Charge–Discharge (GCD) analysis revealed supercapacitance values ranging from 79.43 to 133.26 F/g at 10 mV/s with increasing dopant concentration. These findings underscore the potential of this material for use in energy storage and display technology applications.

Circularly polarised luminescence of cholesteric polymer composite with high concentration of europium complex

ABSTRACT A novel method has been developed for fabricating cholesteric liquid crystal polymer composite containing a luminescent europium complex. It involves creating porous cholesteric polymer networks, introducing the europium complex into the pores and encapsulating it through the UV-induced polymerisation of a nematic diacrylate. The resulting composite exhibits bright red luminescence upon excitation by UV light which is strongly circularly polarised. Such materials have potential applications in display technologies, counterfeit protection and other fields.

Dielectric anisotropy changes in MBBA liquid crystal doped with barium titanate by a new method

In response to the burgeoning interest in enhancing the properties of liquid crystal composites, this research systematically explores the intricate interplay between MBBA nematic liquid crystals and ferroelectric barium titanate nanoparticles. The focus is modulating dielectric properties under temperature, frequency, and an applied electric field. Nuanced insights into temperature-dependent behavior, parallel and perpendicular component alterations, and a nonlinear correlation between nanoparticle concentration and dielectric constant are revealed. The study delves into dielectric anisotropy, indicating a reduction with increasing temperature. Structural analyses validate size reduction and crystal phase maintenance of barium titanate nanoparticles (NPs), emphasizing their impact on dielectric characteristics. Frequency-dependent investigations underscore a consistent decline in permittivity with rising frequency across nanoparticle concentrations. Application of an electric field in filling process of liquid crystal cells reveals irregular changes in dielectric constant, holding promise for tailored applications in display technologies. These comprehensive findings offer valuable insights into manipulating dielectric anisotropy properties of MBBA liquid crystal by a simple method for potential advancements in optoelectronic devices and display technologies.

Deep blue emission and latent finger print detection analysis of zinc gallate nanoparticles

For the first time, Zinc Gallium Oxide is synthesized using LeucasAspera leaves extract as a reducing agent followed by the calcination at 500∘C. The structural, morphological, and optical properties are discussed. The Bragg reflections confirm that ZGO gets crystallized in pure cubic form. The surface morphology consists of agglomerated NPs. The direct energy band gap was found to be 3.1 eV. The photoluminescence analysis excited under 233 nm, and CIE values fall in the blue region of visible spectra. The CCT value was found to be 2748 K which might find an application as a nanophosphor in warm light-emitting diodes. Further, the powder dusting method was employed to collect the latent fingerprints (LFPs) on the pores and non-pores surfaces under UV as well as in day light. The synthesized ZGO exhibits well-resolved ridge patterns that can be used to identify LFPs with clarity. From all these results, the present synthesized ZGO NPs might find an application in display technology as a blue nanophosphor material and for LFP detection in crime investigation.

Progress towards blue emitting MgO-ZnO-Ga2O3 nanocomposites synthesized by bio mediated route

MgO-ZnO-Ga2O3 nanocomposites are synthesized by solution combustion method using Aloe Vera gel as a reducing agent to increase the efficiency of blue emission. The appearance of Bragg reflections corresponding to MgO, ZnO and Ga2O3 clearly indicates the formation of nanocomposites. The surface morphology consists irregular shape and sized NPs. The Energy dispersive X-ray analysis confirms the purity of the sample. The band energy gap was tuned to 3.1 eV. The Photoluminescence excitation and emission spectra was discussed and compared it with emission spectra of individual oxides as well as with other reported blue emitted nanophosphors. Further, the chromaticity coordinates and Color correlated temperature coordinates clearly confirms their warm blue emission. Further, the powder dusting method was employed to collect the latent fingerprints on the pores and non-pores surfaces. The synthesized MgO-ZnO-Ga2O3 nanocomposites exhibits well-resolved ridge patterns that can be used to identify latent finger prints with clarity. From all these results, the present synthesized MgO-ZnO-Ga2O3 nanocomposite might find an application in display technology as a blue nanophosphor material and for latent finger print detection in crime investigation.

Design of 5CB liquid crystal antenna for tunable microwave frequency applications

ABSTRACT Cyanobiphenyls (CBs) are a class of molecules with unique properties that make them highly versatile in various fields. Their anisotropic nature, low viscosity, and sensitivity to external stimuli make them ideal for applications in display technology, photonic devices, sensors, and in tunable antennas. In this article, we present the design and simulation of a 5CB LC antenna for tunable microwave frequency applications due to its fast response time and low dielectric loss than other CB materials. The proposed antenna contains two glass substrates with an air gap of 0.004 mm between them. The lower glass contains a size of 20 × 15 mm2, while the upper glass contains a size of 13 × 15 mm2. The proposed antenna produces two bands when there is an air gap between the glass plates; three bands when diodes are used for the radiating patch; and four bands when 5CB LC material is introduced between the glass plates as a dielectric medium. The same structure produces various frequency bands, which is a notable advantage compared to the existing state of the art. All the results shown in this manuscript were simulated and measured with the body of data available from the literature.

Pioneering ginger juice extract mediated synthesis of magnesium indate nanoparticles

Magnesium indate nanoparticles were synthesized via a biomediated route using ginger extract as a reducing agent followed by calcination. The Bragg reflections confirm the formation of an orthorhombic crystal structure with space group Imma. This was in turn confirmed through Rietveld refinement. The crystallite size and other structural parameters were calculated. Agglomerated irregularly sized and irregularly shaped nanoparticles were observed. The direct band gap was found to be 3.16 eV. Photoluminescence analysis was performed with excitation at 250 nm. The photoluminescence intensity and CIE values drop in the blue region of the visible spectrum. The correlated color temperature was found to be 2748 K. Further, the powder dusting method was used to collect latent fingerprints on porous and nonporous surfaces. The synthesized magnesium indate results in well-resolved ridge patterns that can be used to identify latent fingerprints with clarity. From all these results, the present synthesized magnesium indate nanoparticles might find application in display technology as a blue nanophosphor material and for latent fingerprint detection in forensic science.

Preparation and photoluminescence properties of perovskite Cs4PbBr6/CsPbBr3 quantum dots integrated into lithium-borosilicate glass

Quantum dots (QDs), like all inorganic perovskite cesium lead bromide Cs4PbBr6 and CsPbBr3, have shown potential as multifunctional optoelectronic materials. However, their lack of stability precludes any further practical uses from being developed. Glass as a carrier can effectively resolve these problems while retaining excellent luminescent properties. Herein, a novel perovskite Cs4PbBr6/CsPbBr3 QDs embedded in lithium borosilicate glass was prepared. The phase transition mechanism of Cs4PbBr6/CsPbBr3-based QDs in lithium-borosilicate glass with varying concentrations of Li2O was investigated. Increases in the size and quantity of QDs with increasing contents of Li2O were analyzed using transmission electron microscopy (TEM). A narrow photoluminescence (PL) emission band was observed, with a substantial emission intensity shift and a red-shifted luminescence peak. After 30 days of immersion in water, the QDs maintained approximately 84% of their luminescence intensity. According to the results, the perovskite Cs4PbBr6/CsPbBr3 QDs embedded into lithium borosilicate glass have promising future applications in display technology.

Multifunctional Properties of Ocimum sanctum Linn Leaves Mediated Synthesis of Nanoceria

For the first time, CeO2 nanoparticles (NPs) were synthesized via green solution combustion method using Ocimum sanctum Linn (Tulsi) leaves extract as a reducing agent. The as-formed and calcined (500∘C for 3[Formula: see text]h) CeO2 NPs were characterized with different techniques. The Bragg reflections clearly indicate that the formation of cubic fluorite structure with crystallite size was found to be 10[Formula: see text]nm. The surface morphology of as-formed and calcined sample is made up of large number of irregular shaped NPs. However, agglomeration of the NPs is more in calcined sample. The estimated direct energy band gap from Tauc’s relation was found to be 2.92[Formula: see text]eV and 2.87[Formula: see text]eV for the as-formed and calcined sample, respectively. Photoluminescence spectra, CIE and CCT values clearly indicate that the present nanophosphor might find an application in display technology. Antifungal and anticancer studies show that CeO2 NPs are noncytotoxic against fungus and cancerous cells. Whereas, electrochemical studies show that the synthesized CeO2 NPs show redox peaks and pseudo capacitance and hence it finds importance in supercapacitor applications.

Humidity-Responsive RGB-Pixels via Swelling of 3D Nanoimprinted Polyvinyl Alcohol.

Humidity-responsive structural coloration is actively investigated to realize real-time humidity sensors for applications in smart farming, food storage, and healthcare management. Here, humidity-tunable nano pixels are investigated with a 700nm resolution that demonstrates full standard RGB (sRGB) gamut coverage with a millisecond-response time. The color pixels are designed as Fabry-Pérot (F-P) etalons which consist of an aluminum mirror substrate, humidity-responsive polyvinyl alcohol (PVA) spacer, and a top layer of disordered silver nanoparticles (NPs). The measured volume change of the PVA reaches up to 62.5% when the relative humidity (RH) is manipulated from 20 to 90%. The disordered silver NP layer permits the penetration of water molecules into the PVA layer, enhancing the speed of absorption and swelling down to the millisecond level. Based on the real-time response of the hydrogel-based F-P etalons with a high-throughput 3D nanoimprint technique, a high-resolution multicolored color print that can have potential applications in display technologies and optical encryption, is demonstrated.

Comparative study of multi functional nanoferrites for radiation shielding, photoluminescence and antibacterial properties

• The nanoferrites are synthesized, characterized and analyzed. • Nickel ferrite shows good antimicrobial activity. • Barium Ferrite is found to be good absorbing material for X-ray/gamma radiation. The synthesised nanoferrites ( BaFe 2 O 4 (BFO), ZnFe 2 O 4 (ZFO), NiFe 2 O 4 (NFO) and MgFe 2 O 4 (MFO)) via solution combustion method are characterized, analyzed and compared for the various applications such as radiation shielding, display applications and as antimicrobial properties. The powder X-ray diffraction confirms the cubic for MFO, NFO, ZFO nanoferrites and orthorhombic spinel crystal structure for BFO nanoferrites. The surface morphology shows the agglomerated and irregular shaped nanoparticles with different grain sizes for different chosen nanoferrites. As the atomic number of the metal in the ferrite increases, the IR absorption peak observed in the range 400–650 cm −1 slightly shifting towards higher wavenumber side whereas the other peaks remains unaltered. BFO shows blue and green emission whereas ZFO shows green and orange red emission. MFO and NFO exhibits blue, green and red emission peaks which finds application in display technology. In addition to PL, antibacterial and X-ray/Gamma ray shielding properties are also studied in detail. The direct energy band gap, photoluminescence (PL) intensity, mass attenuation coefficient and percentage of bacterial inhibition was found to depend on crystallite size and atomic number of the metallic element present in the chosen nanoferrite. Among the chosen nanoferrites, the percentage of inhibition for the both gram-positive and the gram-negative bacteria was found to be larger for NFO nanoferrite. It can be concluded that NFO nanoferrite is having good antimicrobial properties than that of the other studied ferrites. Whereas, BFO is observed as good absorbing material for X-ray/gamma radiation. Present comparative study identified the type of nanoferrite suitable for display technology, Antimicrobial and X-ray/gamma absorbing material.

Luminance behaviour of PLEDs with integration of nanomaterials

Incorporation of nanomaterials in device structure is the key to enhance performance of polymer light emitting diodes (PLEDs). The major challenges that impede competence of PLEDs, for application in display technology, are (i) non-availability of stable low work function metals to act as cathode, (ii) presence of charge trapping centers in the polymer chains and (iii) total internal reflection of light at ITO/glass and glass/air interfaces. The foremost problem leads to increase in turn ON voltage of the device and reduction in electron injection from cathode. Low injection and high trapping probability of electrons lead to charge imbalance in the emissive layer and shifting of recombination zone towards cathode. This immensely constrains the formation and radiative decay of excitons in the emissive layer and declines the luminosity of the device. In this review, experimental studies on the integration of nanomaterials in PLED structures to enhance device luminance are presented. The diverse impact of their geometric features, ionization potential, electrical conductivity and refractive index on the carrier transport and light extraction in PLEDs is discussed and a perspective on this evolving research path is provided.

Nanoscale Electrical Excitation of Distinct Modes in Plasmonic Waveguides.

The electrical excitation of guided plasmonic modes at the nanoscale enables integration of optical nanocircuitry into nanoelectronics. In this context, exciting plasmons with a distinct modal field profile constitutes a key advantage over conventional single-mode integrated photonics. Here, we demonstrate the selective electrical excitation of the lowest-order symmetric and antisymmetric plasmonic modes in a two-wire transmission line. We achieve mode selectivity by precisely positioning nanoscale excitation sources, i.e., junctions for inelastic electron tunneling, within the respective modal field distribution. By using advanced fabrication that combines focused He-ion beam milling and dielectrophoresis, we control the location of tunnel junctions with sub-10 nm accuracy. At the far end of the two-wire transmission line, the guided plasmonic modes are converted into far-field radiation at separate spatial positions showing two distinct orthogonal polarizations. Hence, the resulting device represents the smallest electrically driven light source with directly switchable polarization states with possible applications in display technology.

Multicolor and multimode luminescent modulation via energy transfer engineering in Tb3+/Eu3+ co-doped (K0.5Na0.5)NbO3 transparent photochromic materials

Rare earth doped photochromic materials reveal great potential applications in optical memory storage devices due to their excellent reversible luminescence modulation behavior. Nevertheless, the unicolor emission and unimode luminescence modulation in photochromic materials by singly doped rare earth ions difficultly realize the effective optical data readout, then restricting their practical applications in display technology and multifunctional optical devices. Here, the multicolor and multimode luminescent modulation based on photochromic reactions were successfully obtained in Tb3+/Eu3+ co-doped (K0.5Na0.5)NbO3 system, utilizing the energy transfer engineering. The obtained samples exhibit excellent optical transparent (48% in visible light region and 61% in IR region) and multicolor emission from green, yellow-green, yellow, orange to red. After light irradiation, the emission intensity at 546 nm (green emission) and 612 nm (red emission) decreased significantly. The maximum luminescence switching contrast reach up to 68.93% (ΔRIgreen) of x = 0.004, and 69.77% (ΔRIred) of x = 0.016, respectively. The luminescence modulation ratio shows strong dependence on excitation wavelength and Eu contents, and optical transparent can also realize an effective reversible modulation based on photochromic reaction. The energy transfer from Tb3+ to Eu3+ forming two luminescent centers, then part of the energy is absorbed by color centers, which is the source of the multicolor emission and multimode luminescent modulation. These results may provide a new insight for designing multifunction transparent optical storage devices.

How Will Quantum Dots Enable Next‐Gen Display Technologies?

AbstractAlthough QD‐LED technology is still in its infancy, it has received significant interest from display makers. Here, a team of technologists from Sharp review the research and development efforts still needed for it to become an industrial‐level technology for display applications.

Dynamic plasmonic color generation enabled by functional materials.

Displays are an indispensable medium to visually convey information in our daily life. Although conventional dye-based color displays have been rigorously advanced by world leading companies, critical issues still remain. For instance, color fading and wavelength-limited resolution restrict further developments. Plasmonic colors emerging from resonant interactions between light and metallic nanostructures can overcome these restrictions. With dynamic characteristics enabled by functional materials, dynamic plasmonic coloration may find a variety of applications in display technologies. In this review, we elucidate basic concepts for dynamic plasmonic color generation and highlight recent advances. In particular, we devote our review to a selection of dynamic controls endowed by functional materials, including magnesium, liquid crystals, electrochromic polymers, and phase change materials. We also discuss their performance in view of potential applications in current display technologies.

Optimization of the electron transport layer in quantum dot light-emitting devices

Quantum dot light-emitting devices have emerged as an important technology for display applications. Their emission is a result of recombination between positive and negative charge carriers that are transported through the hole and electron conductive layers, respectively. The selection of electron or hole transport materials in these devices not only demands the alignment of energy levels between the layers but also balances the flow of electrons and holes toward the recombination sites. In this work, we examine a method for device optimization through control of the charge carrier kinetics. We employ impedance spectroscopy to examine the mobility of charge carriers through each of the layers. The derived mobility values provide a path to estimate the transition time of each charge carrier toward the emitting layer. We suggest that an optimal device structure can be obtained when the transition times of both charge carriers toward the active layer are similar. Finally, we examine our hypothesis by focusing on thickness optimization of the electron transport layer.