Display Technology Research Articles

Nanostructures in Organic Light‐Emitting Diodes: Principles and Recent Advances in the Light Extraction Strategy

AbstractOrganic light‐emitting diodes (OLEDs) in recent years have emerged as a leading display technology and the popularity of OLEDs is attributed to their numerous advantages, including the ability to produce natural color, achieve a true black state, consume low consumption, exhibit fast response, and be compatible with flexible devices. However, limitations in the performance persist, e.g., the out‐coupling efficiency, which currently stands at ≈20% due to issues such as trapped modes and plasmon loss. Many researchers, therefore, have actively proposed the integration of various nanostructures to address the challenges and enhance OLED performance. The structures play a crucial role in facilitating strong optical interaction with surface plasmon and waveguide modes, thereby improving the extraction of trapped modes. To mitigate the confinement, layers to modulate the refractive index are introduced to extract the confined light and redirect it into the out‐coupled mode. In this review, a comprehensive overview of the principle and effectiveness of these nanostructures in enhancing OLED performance is provided. Various applications of OLEDs are explored based on nanostructures such as nanoparticles, nanomeshes, metasurface, bioinspired structures, and scattering layers. By implementing and refining these nanostructures, significant advancements in OLED performance are anticipated.

Multifunctional application of planar 2D molecule for light-emitting heterostructures

The object of research is the donor-acceptor compound, organic and hybrid heterostructures based on it. The paper is focused on a comprehensive approach to solving the problem of the efficiency of light-emitting devices, finding new technological and design solutions for the use of organic compounds as multifunctional materials for various types of light-emitting devices. The paper presents the multifunctional application of a planar 2D molecule as an emission layer for typical and inverted types of light-emitting heterostructures, as well as a matrix for a host-guest system using inorganic quantum dots. The developed light-emitting structures are characterized by external quantum efficiency typical for fluorescent devices, but good stability over the entire length of the consumption voltage. QLED brightness is 1600 cd·m-2 and EQE 1.4 %, which are good parameters for use in display technology. Organic LEDs based on planar molecules are promising candidates for use in modern lighting systems. A separate advantage of these light-emitting structures is the multifunctionality of using one compound for different types of light-emitting structures, including inverted heterostructures. Special attention is paid to the technological and design implementation of invert structures, since their geometry allows direct connection to the back board of the n-channel transistor on the substrate. In addition, organic LEDs have low energy consumption and are environmentally friendly due to the absence of toxic substances in their architecture, which creates the prerequisites for saving energy resources and reducing the industrial burden on the environment.

Phage Display Technology in Biomarker Identification with Emphasis on Non-Cancerous Diseases.

In recent years, phage display technology has become vital in clinical research. It helps create antibodies that can specifically bind to complex antigens, which is crucial for identifying biomarkers and improving diagnostics and treatments. However, existing reviews often overlook its importance in areas outside cancer research. This review aims to fill that gap by explaining the basics of phage display and its applications in detecting and treating various non-cancerous diseases. We focus especially on its role in degenerative diseases, inflammatory and autoimmune diseases, and chronic non-communicable diseases, showing how it is changing the way we diagnose and treat illnesses. By highlighting important discoveries and future possibilities, we hope to emphasize the significance of phage display in modern healthcare.

From Protein to a Bioactive Peptide: Potent IL‐6 Peptide Antagonist Generated by a Novel Method

ABSTRACTHere, we describe a new technology, designed to accelerate peptide discovery by quick identification and optimization of the residues critical for protein–protein interactions or ligand binding. We called it PepFusion. It is based on ligation of short DNA sequences generated from known ligand‐binding regions. We tested it by selecting peptide antagonists of interleukin‐6 (IL‐6), a key mediator of inflammatory diseases such as rheumatoid arthritis (RA), Crohn's disease, and Castleman disease (CD). The PepFusion library demonstrated superiority over a random library by yielding a peptide with low micromolar affinity for IL‐6, whereas the random library failed. The affinity of the peptide from the PepFusion library was further enhanced by additional rounds of mutagenesis leading to peptide variants with low nanomolar IL‐6 affinity. In addition to generating high‐affinity peptides, our method opens the way to solve the problem of the false positive sequences, which are common with all display technologies.

Shelf-Stable Green and Blue Quantum Dot Light-Emitting Diodes with High Efficiencies.

Quantum dot light-emitting diodes (QLEDs) are promising electroluminescent devices for next-generation display and solid-state lighting technologies. Achieving shelf-stable and high-performance QLEDs is crucial for their practical applications. However, the successful demonstration of shelf-stable QLEDs with high efficiencies is limited to red devices. Here, we developed a solution-based amine ligand exchange strategy to passivate the surfaces of optical ZnO (O-ZnO) nanocrystals, leading to suppressed exciton quenching at the green and blue QD/oxide interface. Furthermore, we designed new bilayered oxide electron-transporting layers consisting of amine-modified O-ZnO/conductive ZnO. This design simultaneously offers suppressed interfacial exciton quenching and sufficient electron transport in the green and blue QLEDs, resulting in shelf-stable green and blue devices with high efficiencies. Our devices exhibit neglectable changes in external quantum efficiencies (maximum external quantum efficiencies of 22.4% for green and 14.3% for blue) after storage for 270 days. Our work represents a step forward in the practical applications of QLED technology.

Arbitrary stylized light-field generation for three-dimensional light-field displays based on radiance fields

Three-dimensional (3D) light-field display technology can reconstruct the spatial characteristics of 3D scenes and provide users with an immersive visual experience without the need for any additional external devices. Here, an arbitrary stylized light-field generation method for 3D light-field displays is presented, and the tripartite constraints are addressed by conducting style transformation in a refined feature space. A multi-dimensional feature refinement module is designed to learn which aspects and regions should be prioritized within the high-level feature grid of the scene, which allows content and style patterns to be better matched and blended. To preserve more structural details and reduce artifacts, a novel global quality and local structure joint loss function is used for optimization. A mask-guided light-field coding method based on ray-casting is employed to accelerate the synthesis of stylized light-field images. Experimental results demonstrate that the proposed method can generate higher-quality stylized 3D light-field content with any given style in a zero-shot manner. Additionally, the method provides two user control extensions to further enrich the ways for the personalized editing of 3D content displayed on 3D light-field displays.

Recent Progress of Quantum Dots Light-Emitting Diodes: Materials, Device Structures, and Display Applications.

Colloidal quantum dots (QDs), as a class of 0D semiconductor materials, have generated widespread interest due to their adjustable band gap, exceptional color purity, near-unity quantum yield, and solution-processability. With decades of dedicated research, the potential applications of quantum dots have garnered significant recognition in both the academic and industrial communities. Furthermore, the related quantum dot light-emitting diodes (QLEDs) stand out as one of the most promising contenders for the next-generation display technologies. Although QD-based color conversion films are applied to improve the color gamut of existing display technologies, the broader application of QLED devices remains in its nascent stages, facing many challenges on the path to commercialization. This review encapsulates the historical discovery and subsequent research advancements in QD materials and their synthesis methods. Additionally, the working mechanisms and architectural design of QLED prototype devices are discussed. Furthermore, the review surveys the latest advancements of QLED devices within the display industry. The narrative concludes with an examination of the challenges and perspectives of QLED technology in the foreseeable future.

Efficient and stable hybrid perovskite-organic light-emitting diodes with external quantum efficiency exceeding 40 per cent

Light-emitting diodes (LEDs) based on perovskite semiconductor materials with tunable emission wavelength in visible light range as well as narrow linewidth are potential competitors among current light-emitting display technologies, but still suffer from severe instability driven by electric field. Here, we develop a stable, efficient and high-color purity hybrid LED with a tandem structure by combining the perovskite LED and the commercial organic LED technologies to accelerate the practical application of perovskites. Perovskite LED and organic LED with close photoluminescence peak are selected to maximize photon emission without photon reabsorption and to achieve the narrowed emission spectra. By designing an efficient interconnecting layer with p-type interface doping that provides good opto-electric coupling and reduces Joule heating, the resulting green emitting hybrid LED shows a narrow linewidth of around 30 nm, a peak luminance of over 176,000 cd m−2, a maximum external quantum efficiency of over 40%, and an operational half-lifetime of over 42,000 h.

Boosting flexible electronics with integration of two‐dimensional materials

AbstractFlexible electronics has emerged as a continuously growing field of study. Two‐dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high‐performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high‐performance and high‐sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design.

Reduced graphene oxide decorated orthorhombic zirconium titanate nanoparticles for display technology and supercapacitor applications

In the present research work, reduced graphene oxide (rGO) decorated zirconium titanate nanocomposites at 1:1 (ZTOr11), 2:1 (ZTOr21) and 1:2 (ZTOr12) ratios are synthesized by green mediated approach. The Bragg reflections of all the three samples consists the Bragg reflections corresponding to orthorhombic zirconium titanate nanoparticles along with the reflections of rGO. The surface morphology consists irregular shaped nanoparticles decorated on the surface of rGO. The transmission electron microscopy shows the presence of both rGO and lattice fringes corresponding to ZrTiO4 matrix. The energy band gap was tuned from 2.7 to 2.61 eV. The photoluminescence emission spectra (λex = 223 nm) and CIE coordinates confirms the blue emission with color correlated temperature less than 5000 K. This clearly indicates that the present synthesized NCs finds an application in the field of display technology. Additionally, electrochemical investigations were conducted to determine the supercapacitance value of the material. The capacitance value vary in the range of 311 F/g to 404 F/g for ZTOr11 NPs, 157 F/g to 194 F/g for ZTOr21, and 36.8 F/g to 163 F/g for ZTOr12 NPS for scan rates 10 to 100 mV/s. The synthesized rGO NCs with ZTO might find an application in display and supercapacitor applications.

9‐3: The Latest Technology Breakthroughs for 31” 4K Flexible Printed OLED TV Display Technology

The flexible printed OLED TV display technology will be able to create new application market, such as rollable/foldable TV, in the future. It's TV Mobiles. Since the TCL (TCL CSOT, Guangdong Juhua Printed Display Technology Co. Ltd. & TCL Corporate Research) has successfully demonstrated the 31” FHD flexible printed OLED TV, there are a lot of technology breakthroughs for improving the panel performance and cost reduction. The co‐planar top gate Oxide TFT device architecture, printing OLED top emission device architecture with new OLED materials, MURA free ink jet printing technology with unique bank design, advanced encapsulation technology with new inorganic material for panel performance improvement are developed. Especially innovative mechanical release technology without using laser lift off technology is developed for cost reduction and production yield up in flexible printed OLED TV MP line. Based on these technology breakthroughs, 31” 4K flexible printed OLED TV with high resolution(142ppi) are fabricated.The performance of 31” flexible printed OLED TV is, 4K high resolution (3840x2160, 142ppi), luminance: FW 150nits, excellent C/R; > 1M:1, color gamut: DCI‐P3: >99%, wide viewing angle (Δu'v' < 0.02): ≥ +/‐ 45°, A/R: 47.75%, and curvature radius: 20mmIn this paper, the panel performance of 31” 4K high resolution flexible printed OLED TV and the latest technology breakthroughs are discussed in details.

P‐154: Enhanced Thermal Stability and High Color Accuracy in GaN‐on‐GaN Homoepitaxy Micro‐LEDs

In the dynamic landscape of display technologies, the advent of Micro‐LEDs has sparked a revolutionary shift, promising unparalleled advancements in visual display capabilities. This study immerses itself in the realm of GaN‐based MicroLED devices, specifically delving into the nuanced effects of varying current density and temperature on the spectra of MicroLEDs with gallium nitride substrates. Through a meticulous comparative analysis, we unravel the optical distinctions between MicroLEDs utilizing gallium nitride and sapphire substrates. Additionally, our exploration extends to the examination of the diverse luminous intensity decay rates experienced by these devices under different substrate temperatures. The findings illuminate the pronounced optical advantages bestowed by gallium nitride substrates in GaN‐based MicroLEDs, providing pivotal insights for the ongoing refinement and enhancement of these cutting‐edge display technologies.

58‐3: Impact of Calibration Sources on Accuracy of Chromaticity Measurements of LED based Displays

The transition from LCD to OLED and µLED as dominant lighting sources for consumer displays in smart devices and AR/VR displays poses new challenges to light measurement. OLEDs and µLEDs exhibit completely different and far greater variations in their spectral distribution, for the measurement of which calibrations with standard light sources e.g. illuminant A are not optimally suited. Metrological traceability is thus particularly important for the interpretation of display measurements using (O)LED based light sources. The paper introduces experimental data on the traceable color accuracy of consumer display measurements based on different display technologies and therefore different variations in spectral distribution. We evaluate the influence of different calibration approaches and calibration sources. We also examine and compare the influence of internal and external spectral reference approaches on traceable error budgets.

97‐3: Late‐News Paper: Enhanced IGZO TFT Performance with Atomic Layer Deposition Parameter Optimization for Large OLED Displays

In this comprehensive study, we rigorously evaluated the applicability of amorphous indium gallium zinc oxide (a‐IGZO) thin films synthesized using atomic layer deposition (ALD) technology in the field of large‐area organic light‐emitting diode (OLED) TVs. The key term to display production is the distribution of device characteristics, and maintaining uniformity can improve productivity yield and product quality. The purpose of this paper is to present guidelines for early application in industry through the process variable exploration results of ALD deposition equipment. The process parameters studied are process pressure and oxygen partial pressure (PO2). We have secured a method to secure device characteristics suitable for display technology through the correlation between a‐IGZO thin film characteristics and device characteristics through corresponding parameters. Our empirical data strongly demonstrate that the threshold voltage (Vth) stabilizes near 0.0 V and consistently achieves device mobility exceeding 15 cm2/Vs. In particular, this study shows that the variability of the Vth characteristic, which is limited to a narrow range of less than ±0.1V, is greatly reduced, and the mobility dispersion is also greatly reduced to less than ±1cm2/Vs. A deeper analytical exploration revealed that the pivotal factors affecting device performance are closely related to oxygen vacancies (Vo) and their dynamic interactions with oxygen molecules. These results will improve the uniformity of device characteristics, and it is believed that the introduction of ALD technology into future display technology will demonstrate improvements in the performance and quality of display products.

91‐4: Temperature Compensation Study of Micro‐LED by Machine Learning

Micro‐LED is a new display technology that offers advantages such as high brightness, high contrast, and low power consumption. However, the performance of Micro‐LED is greatly affected by temperature, leading to color shift easily. To address this issue, this paper proposes a machine learning‐based approach for achieving global compensation, which exhibits advantages including high compensation accuracy, good smoothness, and strong generalization performance. Experimental validation using both measured and simulated data demonstrates that the proposed method achieves a single‐pixel single‐color(R) brightness prediction accuracy of 1% and the brightness prediction of multi‐pixel single‐color(R) also exhibits high accuracy. Consequently, the proposed method enables global brightness compensation and color shift compensation in Micro‐LED.

92‐4: Invited Paper: MicroLED Display Technology Entering Mass Production: Opportunities and Challenges in the New Era

MicroLED display is an innovative display technology with high brightness, wide color gamut, high aperture ratio, and excellent reliability. MicroLED represents a new era in display technology, and it is rapidly entering the mass production phase. It can be used in traditional display applications and can also be applied to various innovative display technologies, such as AR glasses, transparent displays, electric vehicles, or other new use cases, expanding the application of displays into more fields. Therefore, the most critical challenge is how to rapidly reduce costs to enable the widespread adoption of MicroLED.

19‐1: Invited Paper: Zonal Illuminated Non‐emissive Displays for AR Glass

LCoS (Liquid Crystal on Silicon) and DLP (Digital Light Processing) are mature non‐emissive display technologies. Both conventional LCoS and DLP use global illumination so that the whole display panel is illuminated regardless of the content. Therefore,it has challenges of high power consumption, low contrast ratio and so on. In this paper, we proposed a zonal illuminated LCoS and DLP systems, which greatly improve the contrast ratio and reduce the gray box artifacts. In addition, it saves >3x power consumption for typical sparse AR content.

36‐3: Perovskite QDs ‐ Essential for Color, Brightness and Power

In this presentation we give an overview about our perovskite QD solutions for miniLED backlight films (LCD displays) and also in‐pixel QD converters for microLED displays and QD‐OLED displays. We will discuss the advantages of our perovskite QDs for all of these different display technologies and corresponding QD deposition methods.

Reduced Tumor Volume and Increased Necrosis of Human Breast Tumor Xenograft in Mice Pretreated by a Cocktail of Three Specific Anti-HER2 scFvs.

We aimed to assess the effects of a cocktail comprising three specific anti- HER2 scFvs on breast tumor formation in a xenograft mouse model and to evaluate quantitative changes in the tumor using stereological analysis. Three specific anti-HER2 phage antibodies were produced from a scFv-library using phage display technology. The cell binding capacities of the antibodies were assessed via FACS analysis. Soluble forms of the antibodies were prepared by infecting HB2151-E. coli cells and purified using a centrifugal ultrafiltration method. The purification process was evaluated by SDSPAGE analysis. Two forms of scFv cocktails were prepared, soluble scFv and phage-scFv cocktail, which contained an equal amount/phage of each of the three antibodies. Inbred female BALB/c mice were pretreated with 5 and 20 mg/kg of the soluble scFv cocktail and 1011 phage-scFv cocktail/ kg. The mice were then injected with 2×106 SKBR-3 human breast cancer cells. Total tumor, inflammatory and non-inflammatory volumes were estimated using the Cavalieri principle after preparing photomicrograph slides. The anti-HER2 scFvs showed significantly higher binding to SKBR-3 cells compared to the isotype control. SDS-PAGE analysis confirmed the high purification of the scFvs. Stereological analysis revealed that the group pretreated with 20 mg/kg of the soluble scFv cocktail exhibited the highest reductions in total tumor volume, non-inflammatory volume, and inflammatory volume, with reductions of 73%, 78%, and 72%, respectively, compared to PBS-pretreated mice (P-value < 0.0001). The volumetric ratio of necrotic tissue to total tumor volume increased by 2.2-fold and 2- fold in the 20 mg/kg of soluble scFv cocktail and phage-scFv cocktail groups, respectively, compared to the PBS-treated mice (P-value < 0.05). Pre-treatment with a 20 mg/kg anti-HER2 scFv cocktail resulted in a significant reduction in tumor volume and increased necrotic area in a human breast cancer xenograft model, indicating the remarkable anti-tumor effect of the cocktail in vivo.

49‐2: Invited Paper: High Performance Cholesteric Liquid Crystal Technology Development

Cholesteric liquid crystal (ChLC) is a reflective display technology that utilizes ambient light sources to display images, eliminating the need for a backlight. With its bistable characteristics, ChLC displays only require voltage supply during screen updates, resulting in significant energy savings. To cater to various application scenarios, we have developed ChLC reflective displays with different functionalities and sizes. The 7.9‐ inch passive matrix ChLC reflective display offers features such as full‐color capability, wide viewing angles, and fast refreshing rate, making it suitable for electronic book applications. The 24.5‐ inch and 13.3‐inch displays are respectively the largest passive matrix ChLC reflective display and active matrix ChLC reflective display in the world. They incorporate wide temperature range materials and high contrast ratio driving methods, making them highly suitable for outdoor public information display applications.