bluuebunny/crossref_metadata_2025 huggingface dataset:
Giant Magnetoresistance and Magnetocaloric Effect in Highly Textured Ni45Mn36.5In13.5Co5 Alloys
Authors: Chen Fenghua , Shi Wenjian , Liu Jian , Jiang Zhengyi , Xuan Haicheng , Jiang Yong , Zhang Mingang , Zhang Kewei
Published: September 2020

Herein, the giant magnetoresistance (MR) and magnetocaloric effect (MCE) of highly textured Ni45Mn36.5In13.5Co5 alloys are investigated. The Ni45Mn36.5In13.5Co5 alloys are grown using the liquid‐metal‐cooling directional solidification technique. In the scanning electron microscopy (SEM) image, unique bamboo‐like transverse stripes perpendicular to the long axis of grains are observed, which may lead to the giant MR of the sample. For the magnetic field change of 10 kOe, the giant MR value at 268 K is ≈−64%, which is rather big among similar bulk alloys. The MCE is evaluated via the magnetic entropy change. In H⊥ and H∥ magnetic fields of 30 kOe, the maximum entropy change is 13.5 and 15.3 J kg−1 K−1, and the effective refrigeration capacity (RC) reaches ≈108 and ≈117 J kg−1. The detailed results indicate that the MCE properties of the studied alloys vary in different directions under a low magnetic field; however, the difference is not very significant under a high magnetic field.
Influential Ag Concentration in Optical–Electrical Properties of Cd1–2xAg2xSe Photoanodes for Quantum‐Dot‐Sensitized Solar Cell Applications
Authors: Tung Ha Thanh , Huu Phuc Dang
Published: September 2020

Cd1−2xAg2xSe films (as 0% ≤ x ≤ 5%, at%) are synthesized by chemistry method for fabricating anodes in optoelectronic devices. Further, the structural, optical, and electrical properties of the ternary film are extensively investigated. The structural properties of the Cd1−2xAg2xSe anodes are characterized using X‐ray diffraction (XRD) which confirms the cubic structure in the anodes. The optical properties of the thin films are recorded by UV–vis with an effect of metal dopants. Those results are incorporated with Tauc correlation to determine the optical parameters, valence band and conduction band positions, steepness parameter, and electron–phonon interaction in the samples. In addition, the electrical characteristics of thin films are analyzed using their photocurrent density curves, and the characteristic resistances in the optoelectronic devices are determined using the electrochemical impedance spectrum.
Active factor investing: Hedge funds versus the rest of us
Authors: Duanmu Jun , Li Yongjia , Malakhov Alexey
Published: September 2020

We examine whether the success of hedge fund market timing strategies can be replicated. We develop a methodology for creating a portfolio of ETFs to capture risk factor exposures of market timing hedge funds identified using extant market timing measures. We find that the top market timing hedge funds outperform their ETF clone peers and the superior performance cannot be replicated. We show that the irreplicable market timing skills are more profound in certain hedge fund styles. Finally, we provide evidence that the success of market timing strategies is driven by non‐cloneable hedge funds that possess managerial skills.
Observer‐based sliding mode control for state‐saturated systems under weighted try‐once‐discard protocol
Authors: Song Jun , Wang Zidong , Niu Yugang , Hu Jun
Published: September 2020

In this article, the sliding mode control (SMC) problem is investigated for a class of networked state‐saturated systems. In the underlying system, the system states are saturated and unmeasured, and the communication along the sensor‐to‐controller channel is regulated by the weighted try‐once‐discard protocol under which only one sensor node is permitted to transmit data at each instant. The key issue of the addressed problem is how to design both the state observer and the observer‐based sliding mode controller in the presence of protocol scheduling and state saturation. A token‐dependent state‐saturated observer is first constructed, and a desired SMC law is then designed with aid of the updating rule for the actually received measurement. Sufficient conditions are established to guarantee both the asymptotic stability of the SMC system and the reachability of the specified sliding surface. The algorithm for acquiring the desired controller gain matrices is proposed in terms of a convex optimization problem. Finally, the effectiveness of the developed observer‐based SMC design scheme is verified by a simulation example.
Space and time‐resolved monitoring of phosphorus release from a fertilizer pellet and its mobility in soil using microdialysis and X‐ray computed tomography
Authors: Petroselli Chiara , Williams Katherine A. , Ghosh Arpan , McKay Fletcher Daniel , Ruiz Siul A. , Gerheim Souza Dias Tiago , Scotson Callum P. , Roose Tiina
Published: September 2020

Phosphorus is an essential nutrient for crops. Precise spatiotemporal application of P fertilizer can improve plant P acquisition and reduce run‐off losses of P. Optimizing application would benefit from understanding the dynamics of P release from a fertilizer pellet into bulk soil, which requires space‐ and time‐resolved measurements of P concentration in soil solutions. In this study, we combined microdialysis and X‐ray computed tomography to investigate P transport in soil. Microdialysis probes enabled repeated solute sampling from one location with minimal physical disturbance, and their small dimensions permitted spatially resolved monitoring. We observed a rapid initial release of P from the source, producing high dissolved P concentrations within the first 24 h, followed by a decrease in dissolved P over time compatible with adsorption onto soil particles. Soils with greater bulk density (i.e., reduced soil porosity) impeded the P pulse movement, which resulted in a less homogeneous distribution of total P in the soil column at the end of the experiment. The model fit to the data showed that the observed phenomena can be explained by diffusion and adsorption. The results showed that compared with conventional measurement techniques (e.g., suction cups), microdialysis measurements present a less invasive alternative. The time‐resolved measurements ultimately highlighted rapid P dynamics that require more attention for improving P use efficiency.
3‐3: Novel Microstructure Film to Improve Viewing Angle of Multi‐Domain Polymer Sustained Alignment LCD
Authors: Tien Kun-Cheng , Hung Yu-Hsuan , Wu Cian-Rou , Lin Chin-An , Li Jia-Hao , Liao Chien-Huang
Published: September 2020

Novel microstructure film laminated on the 8‐domain VA‐mode LCD was proposed to get better viewing angle experience. Furthermore, the viewing angle is IPS‐like level with contrast ratio > 5000, but the transmittance loss is less than 5% with the collimated backlight.
3‐4: Novel LCD Pixel Design with Extra Large Aperture Ratio for PsVA Mode Display
Authors: Borjigin Surgaltu , Feng Zhengyu , Shi Zhiqing , Zeng Limei , Chen Shu-jhih , Lee Chia-yu , Zhang Xin
Published: September 2020

To improve the transmittance of the liquid crystal display panel, a transparent ITO electrode is adopted to replace the metallic common electrode and serves as a storage capacitor in the PsVA mode display. The transmittance is improved by 15% compared with the common design. Since the ITO com electrode also blocks electric field from the metallic lines, a high contrast value over 6000 can be achieved though black matrix structure is not adopted. Such pixel design with extra large aperture ratio can be applied to future high resolution display devices.
4‐2: Anti‐Glare Cover Glass Optical Properties Dependence on the Display Module Configuration
Authors: Isshiki Masanobu , Inouye Aichi , Yamamoto Aya , Kobayashi Yusuke
Published: September 2020

We have optimized Anti‐Glare (AG) surface topography. However, the optical properties of AG (“Sparkle”, “Diffusion”, and “Transmissive Distinct of Image”) depend not only on the AG topography, but also on the structure of the module. We will show the complicated dependence and show the direction to improve AG optical properties.
4‐3: Late‐News Paper: OLED Device Technologies for Automotive Application
Authors: Mori Shigeru , Hamada Keita , Hanashima Hiromu , Shimoda Masamichi , Yanase Jiro , Matsueda Yojiro , Tanabe Hiroshi
Published: September 2020

We have demonstrated an OLED display with the high luminance of 1000 nit and long lifetime of LT80 > 1000 hours at 85°C for automotive application. Our display features a highly stable EIL/ETL structure at high temperature and low angular colorshift technology for red emission.
4‐4: Increase of Contrast in 3D HUD Using an Active Parallax Barrier
Authors: Sato Akinori , Kusafuka Kaoru , Kakeya Hideki
Published: September 2020

The authors propose a method to increase the contrast of image by suppressing black luminance (Min Lum) in a 3D head up display based on an active parallax barrier. In the conventional active barrier, the electronic barrier is controlled to follow the motion of the observer and to increase the resolution by time‐division multiplexing. In the proposed method, the barrier is closed in the black area of the image, which suppresses black luminance and increases the contrast of 3D image.
5‐4: Invited Paper: Current Challenges in Augmented‐Reality Waveguide Display Technology
Authors: Waldern Jonathan D. , Grant Alastair J. , Popovich Milan M.
Published: September 2020

Current challenges in AR waveguide technology are reviewed with reference to a new low‐cost compact wide‐field‐of‐view color waveguide display reference design using integrated dual axis beam expansion and a compact picture generation unit.
6‐3: Efficient and Long Lifetime Blue TADF and Deep Blue Hyper Fluorescent Materials and Devices
Authors: Karthik Durai , Ahn Dae Hyun , Maeng Jee Hyun , Lee Hyuna , Yoo Hanjong , Lampande Raju , Lee Ju Young , Kwon Jang Hyuk
Published: September 2020

We report a blue TADF device with high efficiency of 26.3% and long device lifetime (LT90) of 93 hrs at 1000 cd/m2, respectively. This good device lifetime is achieved by avoiding material degradation by using high bond dissociation energy materials. In addition, a deep blue hyper fluorescence device using KH‐2 as an emitting dopant shows high EQE of 36.8% with CIE of (0.14, 0.08).
7‐1: Distinguished Paper: Alleviation of Abnormal NBTI Phenomenon in LTPS TFTs on Polyimide Substrate for Flexible AMOLED
Authors: Lee Jaeseob , Lee Yongsu , Kang Taewook , Chu Hyeyong , Kwag Jinoh
Published: September 2020

This letter investigates the negative‐bias temperature instability (NBTI) behavior of p‐channel low‐temperature polycrystalline silicon thin‐film transistors (LTPS TFTs) on plastic substrate. The measurements reveal that the threshold‐voltage positive shift is highly correlated to the passivation of grain‐boundary trap states. By applying the established phenomenon such as NBTI recovery and H diffusion from PI substrate, a new model is introduced to explain mechanism and verified by the experiment. With the thick buffer & bottom metal layer or newly processed PI substrate, we succeeded in adjusting the NBTI behavior of LTPS TFTs on plastic substrate.
7‐2: Invited Paper: Hot Carrier Degradation in High Mobility Metal Oxide Thin Film Transistors
Authors: Uraoka Yukiharu , Takahashi Takanori , Kise Kahori , Bermundo Juan Paolo , Fujii Mami N. , Uenuma Mutsunori , Ishikawa Yasuaki
Published: September 2020

The existence of hot carriers in an oxide thin‐film transistor was confirmed by using an emission analysis technique. It has been clarified that degradation due to hot carriers causes degradation phenomena such as a decrease in on‐current without shift in threshold voltage, which has not been seen so far, in high‐mobility device. Moreover, it was confirmed by photo emission analysis that the main degradation factor was hot carriers against dynamic stress in which a pulse voltage was applied to the gate.
7‐3: High ESD Robustness and Low Visible Light Reflectance Design for LTPS‐TFTs on Glass Substrates in Modular Micro‐LED Displays
Authors: Son Seongho , Park Wonsoon , Lee Jongsung , Seung Wanchul , Lee Changjoon , Seol Byongsu , Park Taesang , Chun Jung-Hoon
Published: September 2020

Low‐temperature poly‐silicon thin‐film transistors (LTPS‐TFTs) on glass substrates in modular micro‐LED displays have metal electrodes which are externally exposed to connect LED chips and pads. This structure increases the risk of electrostatic discharge (ESD) from the external environment. Furthermore, glass substrates cause high visible light reflectance. To improve the ESD robustness and reduce visible light reflectance, a backplane structure with a black fine metal mesh is proposed. Modular micro‐LED displays with the proposed structure achieved the ESD tolerance higher than 8kV through the standard system‐level ESD test and reduced the average visible light reflectance by more than 80%.
8‐1: Invited Paper: Development of High‐Temperature Stable Red OLEDs for Automotive Lighting
Authors: Kondakova Marina , Eser Juergen , Buechel Michael , Knipping Joerg , Lindla Florian , Boroson Michael , Spindler Jeffrey
Published: September 2020

In this work we describe the basics of technology employed to develop high efficiency red OLED panel for automotive lighting. The devices exhibit high luminance, long lifetime even at elevated temperatures and minimal color change with viewing angle. The described method of LT70 estimation can be used for accurate prediction of device operational stability at various driving conditions.
8‐2: Invited Paper: High Refractive Index Materials for Display and Lighting Applications
Authors: Monickam Selina , Newman Todd , Szychowski Brian , Williams Serpil Gonen , Choi Sang-Hun
Published: September 2020

Pixelligent's nanocrystal dispersions are designed for demanding optical applications including OLED and LED lighting and displays, AR/VR/MR and CMOS sensors where high refractive index is required. In one example, our ZrO2 nanocrystal formulations result in dramatic light extraction improvement in OLED lighting devices achieving efficacy > 90 lumen/Watt at 3,000 cd/m2 surpassing the current state‐of‐art.
9‐2: Manufacturing Process for Mass Production of Micro‐LED Displays and High‐Speed and High‐Yield Laser Lift‐Off Systems
Authors: Kajiyama Koichi , Suzuki Yoshikazu , Hirano Takafumi , Yanagawa Yoshikatu , Fukaya Koichiro , Okura Naoya , Okuno Takeshi , Shimoura Atushi
Published: September 2020

In our previous work, we proposed and evaluated processes and equipment to facilitate the mass production of micro LED (light emitting diode) displays. The new technologies include LLO (laser lift off), mass‐transfer, color conversion and backplane with micro Si chip. We quantitatively evaluated them and report results.
9‐4: Applying FPD panel and manufacturing technologies to high growth segments, alternative applications, and new business models
Authors: Annis Charles A.
Published: September 2020

This study analyzes how the FPD supply chain complanies can apply their proprietary technologies to high growth segments, alternative applications, and new business models. It uses examples of x‐ray sensors, LC antennas, and fan out panel level packaging to demonstrate business diversification strategies as the FPD industry undergoes unprecedented techonology and market changes.
11‐4: Invited Paper: Virtual Prototyping and Testing of Automotive Capacitive Touch Sensors
Authors: Zagkanas Vasileios N. , Orlis Dimitris A. , Daskalou Christos G. , Bouzianas George D. , Temming Carsten
Published: September 2020

This paper presents how virtual prototyping and testing through Fieldscale SENSE can effectively support the product development process of automotive capacitive sensor systems. A capacitive sensor designed by Volkswagen Group Innovation to be placed at the steering wheel of a car, has been used as a case study. It is shown that a combination of electrostatic and static current simulations as well as SPICE analysis supported by the automatic extraction of the equivalent circuit, enable the virtual testing of capacitive sensors according to automotive electronics testing standards.
13‐2: Late‐News‐Paper: How to Reduce Harmful Blue Light on OLED Devices
Authors: Bang Jinsook , Yim Sanghoon , Kim Donghoon
Published: September 2020

This study shows how to reduce the harmful blue light of OLED displays. The results demonstrate that the ratio of harmful blue light depends on the blue dopant‐host spectrum and the resonance strength. We define the harmful blue light spectrum to cover between 415 nm and 455 nm. The ratio of harmful blue light decreases as the blue dopant‐host spectrum shifts toward longer wavelengths. However, a color change could occur from the original one, which contains a shorter spectrum area. In order to maintain the other properties, we simultaneously change the full width at half maximum (FWHM) and the peak wavelength (Wp). As a result, the harmful blue light ratio is reduced from 12% to 7% compared with previous materials. This new technology is already being applied in mass production.
14‐2: Invited Paper: OLED Display Incorporating an Organic Image Sensor
Authors: Niikura Yasuhiro , Hatsumi Ryo , Kamada Taisuke , Yamashita Akio , Watanabe Kazunori , Kawashima Susumu , Yamauchi Ryo , Katayama Masahiro , Adachi Hiroki , Kusunoki Koji , Kubota Daisuke , Eguchi Shingo , Yamazaki Shunpei
Published: September 2020

We fabricated a prototype display that incorporates an organic image sensor in the same pixel as OLEDs through side‐by‐side patterning. The display enables fingerprint image capturing and scanning at any location on the entire display region. We fabricated a flexible OLED display with the aforementioned structure.
15‐2: Gen 10 Excimer Laser Annealing System
Authors: Fuji Takahiro , Yamaguchi Yoshihiro , Suzuki Yuki , Mikami Takahiro , Tanigawa Sadao
Published: September 2020

We have developed Excimer Laser Annealing system for Gen. 10 glass substrates for mass production which appropriates high resolution and large sized displays. Performance of the ELA system meets sufficiently compared to conventional ELA system. We will describe some key features and performance evaluations of the advanced ELA system.
16‐2: A 4‐inch Full Color Active‐matrix Mini‐LED Display based on 0408 Chip and 500um Pixel
Authors: Yin Yongming , Sun Yang , Gao Lu , Fan Jack , Zhang Lijun , Liu Minggang , Hua Zhiheng , Yang Bo , Wang Zeng , Fu Jianhang , Liang Pengfei , Hwang Jason , Chen Shu-jhih , Zhang Xin , Meng Hong
Published: September 2020

Mini/Micro LED are recognized as the fourth generation display technology due their superior performance. Backlights based on active‐matrix Mini‐LED (AM‐MLED) have been adopted in LCD modules and would soon be put into mass production. In this paper, a 4‐inch full‐color AM‐MLED Display based on 0408 chip and 500um pixel pitch was presented. The chip size and pixel pitch reported here are smallest till now for AM‐MLED based on glass backplanes. We believe this result would further extend the application of Mini‐LED in direct display area.
17‐5: Distinguished Student Paper: Birefringent Light‐Shaping Film for Mini‐LED Backlights
Authors: He Ziqian , Yin Kun , Hsiang En-Lin , Li Ming-Chun , Lee Seok-Lyul , Tien Kun-Cheng , Wu Shin-Tson
Published: September 2020

A new birefringent light‐shaping polymer‐dispersed liquid crystal (PDLC) film is experimentally demonstrated for mini‐LED backlit liquid crystal displays. Due to its angle‐sensitive transmission properties, such a volumetric PDLC diffuser helps to spread out the backlight faster, which in turn results in fewer mini‐LEDs or thinner display panel.
17‐6: Invited Paper: 4K HDR "Stacked‐Panel" TV Based on Dual‐Cell LCD
Authors: Liu Weidong , Mu Linjia , Xu Aichen , Zhang Yuxin , Qiao Mingsheng
Published: September 2020

This paper mainly introduces the development of 4K HDR "Stacked‐Panel" TV based on Dual‐Cell LCD. Dual‐Cell technology enables significant improvement in display contrast, but the drop of transmittance limits the increase of peak luminance. In this work, we innovatively designed the pixel control algorithm for Dual‐Cell LCD. Moreover, the peak luminance and color gamut were further improved using direct‐lit backlight and QD technology, leading to the outstanding HDR display effect.
18‐1: Invited Paper: Holographic Optical Elements for Automotive Windshield Displays
Authors: Redmond Ian R.
Published: September 2020

The capabilities and benefits of holographic optical elements (HOE's) for use in automotive windshield displays are described. These are based on photopolymer materials laminated to or within the windshield. Two types of HOE enabling compact augmented reality head up displaysand in‐plane transparent displays are outlined and their complementary features described.
18‐3: Impact Study of Windshield Geometry on the Subjective Customer Perception for Augmented Reality Head‐up Displays (AR HUD)
Authors: Wagner Daniel , Schneider Matthias , Dross Florian , Langer Stefan , Zeidler Susanne , Ganz Thomas , Lemmer Ulrich
Published: September 2020

New Generations of Head‐up Displays (HUD) are expected to grow in size and projection distance. For these reasons, even smallest deviations in the windshield geometry may cause new optical image defects. These image defects need to be specified, measured, and correlated with subjective customer perceptions. Based on a customer study (n=54), this paper gives first indications that heterogeneous image quality disturb customers.
19‐1: Distinguished Paper: Differences between oculomotor and perceptual artifacts for temporally limited head mounted displays
Authors: Goettker Alexander , MacKenzie Kevin J. , Murdison T. Scott
Published: September 2020

We used novel perceptual and oculomotor measures to understand the negative impacts of low (phantom array) and high (motion blur) duty cycles with a high‐speed, AR‐like HMD. We quantified this tradeoff and found that eye movements were adversely impacted by low duty cycles, even when no artifact was reported.
19‐2: Vergence‐Accommodation Conflicts in Augmented Reality: Impacts on Perceived Image Quality
Authors: Erkelens Ian M , MacKenzie Kevin J
Published: September 2020

This study quantifies the 'Zone of Clear Vision' (ZoCV), which defines the magnitude of a vergence‐accommodation conflict (VAC) that a user can accept in a binocular augmented reality environment before there is a perceived impact on image quality. Results indicate that the ZoCV extends up to 0.5 diopters on either side of a fixed focus display. This data correlates well to the Zone of Comfort, established from VR systems and suggests that an impact of perceived image quality may predict the buildup of visual discomfort overtime. Further, a subset of participants reported an impact of image quality on real‐world content when simultaneously viewed with virtual content rendered with VAC, suggesting that rendered AR content outside the ZoCV can inadvertently impact some users view of the world.
19‐3: Foveated Brightness Control Technology for VR Applications
Authors: Jeong Won-Been , Kim Jeong-Sik , Lee Seung-Woo
Published: September 2020

This paper proposes a foveated brightness control (FBC) technology for VR applications. FBC technology reduces brightness of the unfoveated area. Through subjective experiments, threshold values of lightness reduction ratio (LRR) depending on four different gaze points are found where people cannot recognize the difference while the brightness of unfoveated area is reduced. It is found that the LRR threshold for gazing up is lower than that for gazing down and the LRR threshold for gazing left or right depends on dominant eye.
20‐4: Study on the Effect of OLED Device Lifetime Improvement according to Hole Injection Barrier and p‐Dopants
Authors: Hong Jaechul , Kang Yoonsu , Lee Jinyoung , Jeong Seungjae , Ahn Jaehong , Chu Changwoong
Published: September 2020

In testing a special anode pretreatment technique to improve the lifetime of fluorescent blue devices, we found that the characteristics of two different blue devices with similar device lifetimes appeared to be significantly different after pretreatment. One device experienced a slight rise in drive voltage after pretreatment, but an increase in efficiency and lifetime, while a dramatic decrease in both. Accompanied by device measurement and analysis, it was found that the cause of lifetime degradation was the formation of a hole injection barrier, which resulted in the reduction of charge accumulation and recombination in the emitting layer. Therefore, it was confirmed that the increase of p‐type doping concentration can overcome the lifetime degradation phenomenon by increasing the hole and also increase the lifetime by lowering the barrier by additional mild plasma treatment of anode.
22‐1: Formation of Silicon‐Based Thin‐Film Encapsulation for Fabrication of Highly Flexible OLED Devices
Authors: Jung Eun , Huh Myung Soo , Key Sung Hun , Kim Jung Gon , Jeon Dong Pyo , Kim Sae Hong , Jang Choel Min
Published: September 2020

The commercialized OLED display is one of the most attractive display in the 21st century. The OLED display is able to manufacture as a deformable display then before, such as foldable, rollable, and stretchable. Manufacturing the deformable display requires thinner and/or more flexible layers in the inner display. To make a high performance barrier preventing moisture and oxygen for the thinner thin film encapsulation (TFE), we have studied the process for inorganic layer by ALD (Atomic layer deposition) and organic layer by CVD (Chemical vapor deposition). In this study, we evaluated the OLED device deposited by ALD and CVD encapsulation layers. The method introduced in this study confirmed the same level of encapsulation characteristics even in a thickness of about 35% thinner than the conventional thin films encapsulation layer. To perform the evaluation according to the bending radius, a flexibility evaluation of 200,000 cycles was performed at room temperature. Finally, we were confirmed that this encapsulation layer by above process was thinner and more flexible while maintain the encapsulation characteristic rather than conventional encapsulation layer.
22‐2: An Ultra‐thin Flexible Thin Film Encapsulation Structure with High Transmittance and Reliability
Authors: Wang Youwei , Sun Tao , Qin Chengjie , Zhang Song , Wang Tao , Zhang Ziyu , Hong Rui
Published: September 2020

We report an ultra‐thin film encapsulation structure composited of atomic layer deposition layer and organic layer, which show a 4% improvement in transmittance with tandem TFE film, especially for blue region (94% up to 99%) and a 60% thickness decrease of inorganic layer. The TFE film shows an excellent flexibility performance, there was no crack after 60/90 500 hour static bending for R2. It also shows good reliability, storage for 85/85 500h, which indicates a great potential application in flexible display, especially for bendable display.
24‐1: Invited Paper: Development of High Quality IGZO‐TFT with Same On‐Current as LTPS
Authors: Ito Kazuatsu , Mehadi Aman , Sano Masahito , Murashige Shogo , Ishida Izumi , Takeda Yujiro , Matsukizono Hiroshi , Makita Naoki
Published: September 2020

IGZO TFT with the same on current as n‐LTPS was fabricated. The saturation on current reached 1 mA, and the off‐state leakage current was below 1 pA. The Vth shift under PBT / NBT stress test for the IGZO TFT was 0.1 / −0.1 V, respectively, which was better compared to the n‐LTPS. Furthermore, the IGZO TFT showed an ideal Id‐Vd curve (output characteristics) without any kinks. These results indicate that, a variety of backplanes, from small size smartphones to large area TVs, are possible to be made in a single factory of IGZO.
26‐2: Invited Paper: A Holographic Waveguide Display with Polarization Volume Gratings
Authors: Zhang Yuning , Cui Jingyi , Weng Yishi , Xia Jun
Published: September 2020

We report a polarization sensitive volume grating in this paper. In addition, a double‐layer waveguide using this kind of grating as coupling elements has been demonstrated to realize a full‐color near‐eye display. The results show that about 85% diffraction efficiency covering all of the red, green and blue spectra with a diagonal FOV of around 35 ° is obtained for the proposed waveguide prototype.
26‐3: Tolerancing Capabilities of Crossed Gratings Versus Linear Gratings
Authors: Crai Alexandra , Wang Kai , de Cunsel Sébastien , Valera Salim
Published: September 2020

Diffractive waveguides have been recognized as a promising platform for large scale manufacturable components for augmented reality (AR) devices. WaveOptics waveguides are designed to overcome the three major challenges of AR wearables: design, cost and optical performance. In this paper, some design tolerances of diffractive waveguides are modelled focusing on two waveguide structures, a WaveOptics 2D grating and a linear grating. Their tolerance to a glass substrate wedge and grating pitch mismatch are compared, showing that the WaveOptics waveguides allow better tolerance than the waveguides with typical linear gratings.
28‐3: Pixel Design for Transparent MicroLED Display with Low Blurring
Authors: Feng Zhengyu , Wu Yongwei , Shi Zhiqing , Surigalatu  , Mei Zengli , Chen Shu‐jhih , Lee Chia‐yu , Zhang Xin
Published: September 2020

A quasi periodic pixel structure is proposed to suppress the blurring of the transparent microLED display. By allocating the transparent areas of the subpixels, the diffraction angles and intensity of each order are reduced so that the improved see through image with less blur can be observed. By using 2D FFT simulation method, the maximum diffraction intensity of the transmitted light can be decreased by 70% by choosing proper pixel geometrical parameters. Such pixel design is simple with high feasibility and transparent microLED display with such design can be applied to a variety of occasions including head‐up display for vehicles where a clear see through image with blur suppression is crucial.
29‐2: Invited Paper: Mechanics of Bendable Glass Substrates
Authors: Gross Timothy M. , Coble Claire R. , Kuo Kuan-Ting , Lezzi Peter J. , Ono Toshihiko
Published: September 2020

Fracture mechanics are utilized to successfully predict the allowable bend radii achieved through experimentation for ion‐exchanged glass having thicknesses of 25 to 125 microns. The origin of the non‐monotonic relationship between puncture resistance and glass thickness is also described.
31‐2: Invited Paper: Nanostructures Oxide Thin‐Film Transistors Fabricated by Near‐Field Nanolithography with Enhanced Device Performance
Authors: Huang Kairong , Chen Zihao , Hu Sujuan , Gao Lichao , Liu Chuan
Published: September 2020

We have developed oxide TFTs with nanostructure by using a strategy based on near‐field nanolithography, such as wrapping insulator structure with nano‐splitting active layer or nanoscale and periodic degenerately doped heterostructures. These nanostructured TFTs enhanced in device performance, compared with normal single gate homogeneous IGZO TFTs.
34‐1: Invited Paper: Towards Efficient and Stable Printed Single‐layer OLEDs
Authors: Kotadiya Naresh B. , Blom Paul W.M. , Wetzelaer Gert-Jan A.H.
Published: September 2020

The efficiency and stability of single‐layer polymer light‐emitting diodes is compromised by unbalanced charge transport, absence of triplet‐exciton harvesting and low photoluminescence quantum efficiencies. We demonstrate that tuning the energy levels of the organic semiconductor can prevent charge trapping, which is the main cause of unbalanced charge transport. By additionally using a novel strategy to enhance charge injection, efficient single‐layer organic light‐emitting diodes are presented based on a trap‐free organic semiconductor exhibiting thermally activated delayed fluorescence.
34‐2: Distinguished Paper: Development of 55inch 8K AMOLED TV by Inkjet Printing Process
Authors: Wu Zhongyuan , Yan Liangchen , Li Yongqian , Shih Huaiting , Feng Xuehuan , Kim Taejin , Peng Yuqing , Yu Jianwei , Dong Xue
Published: September 2020

In this paper, we presented 55 inch 8K4K AMOLED TV employing coplanar Oxide TFT backplane, top emissive inkjet‐printing OLED device, Gate Driver on Array(GOA) and compensation technologies. It is so far the largest prototype AMOLED TV fabricated by using inkjet printing process with 8K resolution. It shows the stunning display quality thanks to the high resolution and fast refresh frequency. It proves that the inkjet printing process is not only cost competitive but also can deliver premium display.
35‐4: High Sensitive Pen Writing Solution Based on Mechanical Sensing
Authors: Seomoon Hee , Hong Wonki , Baek Jongin , Park Wonsang , You Bonghyun
Published: September 2020

When pen, pressure, and touch sensor are respectively applied to a new form‐factor display, it becomes difficult to secure a folding flexibility due to increase in thickness. To solve these problems, this paper proposes an integrated user interface solution that can realize pen, pressure, and touch sensor functions with one integrated sensor. The Multi‐channel structured electrode is patterned on the substrate, and the total thickness of this integrated sensor is less than 30um, which is able to be applied to the bottom of the new form‐factor display panel to achieve a precision of 0.35mm and a sensitivity of 10gf approximately, which is the brushstroke level. It is confirmed that the possibility of performing three functions of pen, pressure, and touch with one hardware.
38‐2: Magnifying Viewer using Poly‐Si Thin‐Film Phototransistor and Liquid‐Crystal Micro‐Lens Array
Authors: Kimura Mutsumi , Kitajima Shuhei , Li Kun , Chu Daping
Published: September 2020

We have confirmed fundamental functions of a flatpanel imager using a poly‐Si thin‐film phototransistor and liquid‐crystal micro‐lens array. It is found that the electric current measured in the pixel on the white area is definitely larger than that on the black area. Particularly in this paper, it is clarified that the current difference for the lens‐on state is more obvious than that for the lens‐off state, and that for the polarizer‐on state is also more obvious than that for the polarizer‐off state. The experimental results are the same as what we expect and indicate the excellent effect of the liquid‐crystal micro‐lens array on the flatpanel imager using a poly‐Si thin‐film phototransistor. The magnifying viewer can be high‐resolutional by the flatpanel imager using the poly‐Si thin‐film phototransistor and liquid‐crystal micro‐lens array.
38‐3: A Novel Gate Driver Circuit Employing IGZO TFTs for External Compensation
Authors: Feng Xuehuan , Li Yonggian , Yuan Can , Yuan Zhidong , Xu Pan , Han Dongxu , Meng Song , Wei Xiaolong , Xie Enming , Bao Wenchao , Liu Fengjuan , Wu Zhongyuan , Yu Jianwei , Dong Xue
Published: September 2020

We present a novel gate driver circuit which has been applied in 55inch 8K4K printing OLEO panel not only for display images but also for sensing TFT characteristics for external compensation. This circuit is verified at high temperature (50°C) companied with high humidity (80% RH) during 500 hours with no problem through 5 inch experiment panels. And it also can work normally at very low temperature (−20°C). Meanwhile, this novel GOA (Gate driver on array) circuit helps our panel achieve a narrow bezel smaller than 8mm.
38‐4: A 2T1C AMOLED Display with External Compensation Reducing On‐Panel Current Variations to 0.079%
Authors: Verschueren Lynn , Ameys Marc , Velazquez Lopez Mauricio , Smout Steve , Ke Tung Huei , Vandenplas Erwin , Kronemeijer Auke Jisk , Heremans Paul , Genoe Jan , Dehaene Wim , Myny Kris
Published: September 2020

This paper presents a new compensation principle using a 2T1C pixel circuit. The implementation shows significant improvement in uniformity for all grey‐levels, due to compensation for both VT and β‐factor variations. The resulting current variation after compensation in the characterized display area reaches values down to 0.079%.
39‐2: Distinguished Paper: A 14‐Gb/s Dual Mode Receiver with MIPI D‐PHY and C‐PHY Interfaces for Mobile Display Drivers
Authors: Kim Tae-Jin , Hwang Jong-Il , Lee Sangkyu , Chun Sengsub , Ryu Seong-Young , Lee Soo-Joo , Cho Hyunwoo , Tak Wonho , Kim Yong-Jae , Lee Hoomin , Pae Hansu , Lim Hyun-Wook , Lee Jae-Youl
Published: September 2020

This paper presents a 14‐Gb/s dual mode receiver with MIPI D‐PHY and C‐PHY interfaces for mobile display drivers. To reduce size overhead from the dual mode interfaces, we propose the termination circuit that can share 50‐Ω terminations and common‐mode capacitors while maintaining a perfectly matched load balance. The proposed dual mode receiver supports up to 14 Gb/s total bandwidth in each interface mode, resulting in broad compatibility with application processors. A mobile display driver using the proposed dual mode receiver is fabricated in a 28‐nm high‐voltage CMOS process and verified up to 3.5 Gb/s per lane in the D‐PHY mode and 2.2‐Gs/s per lane in the C‐PHY.
40‐1: Invited Paper: Fast‐Switching Liquid Crystal Devices for Near‐Eye and Head‐Up Displays
Authors: Zhan Tao , Xiong Jianghao , Tan Guanjun , Wu Shin-Tson
Published: September 2020

Fast‐switching liquid crystal Pancharatnam‐Berry (PB) optical elements for near‐eye and head‐up displays are reviewed. A submillisecond‐response PB deflector helps double the apparent resolution and enable foveated display with eye‐tracking. A PB lens enables time‐ and polarization‐multiplexed multi‐focal‐plane displays to overcome the vergence‐accommodation conflict.
40‐3: Invited Paper: A Large RGB‐achromatic Metalens for Virtual/Augmented Reality Applications
Authors: Li Zhaoyi , Lin Peng , Huang Yao-Wei , Park Joon-Suh , Chen Wei-Ting , Shi Zhujun , Cheng Ji-Xin , Capasso Federico
Published: September 2020

In this talk, we will present a new platform for a virtual/augmented reality system based on a metalens and a fiber scanning display. The metalens was designed for achromatic focusing of blue, green, and red light. The fiber scanning display features combined desired merits of high resolution, high brightness, high dynamic range and wide color gamut.
42‐4: LTPS TFT‐LCD with In‐cell Optical Fingerprint Scanner
Authors: Liu Bozhi , Chen Binbin , Wu Xiaoxiao , Cai Xuanxian , Shi Xiaoqi , Huang Min , Wu Jiaqian , Wang Hailiang , Lan Xuexin , Chen Guozhao , Li Junyi
Published: September 2020

LTPS image sensor (LIS) driven by active pixel senor (APS) circuit based on LTPS backplane technology is demonstrated. Optical solution for LCD with in‐cell optical fingerprint scanning function is discussed. A 400PPI LTPS‐TFT LCD with in‐cell touch and in‐cell screen fingerprint scanning function is designed to realize fingerprint image capture when finger is 1.0mm height over the LIS array.
43‐3: Ab‐initio Simulation of Doped Injection Layers.
Authors: Symalla Franz , Fediai Artem , Armleder Jonas , Kaiser Simon , Strunk Timo , Neumann Tobias , Wenzel Wolfgang
Published: September 2020

Optimization of doped injection layers in state‐of‐the‐art OLEDs via experimental trial&error by tuning host‐dopant combinations/concentrations is time‐consuming and costly. We present a multiscale‐simulation approach to investigate doping on microscopic level, i.e. the impact of microscopic properties on doping performance, and illustrate how to apply simulations towards materials design.
45‐4: Late‐News Paper: A Novel ADS Display Technology without Light Leakage
Authors: Wang Feifei , Zhan Hongming , Shao Xibin , Kang Zhao , Huang Hua , Ji Lintao , Wang Kaixuan , Chen Xi , Wang Zhangtao , Xue Hailin , Yuan Guangcai , Lin Lifeng
Published: September 2020

In the field of LCD, Advanced Super Dimension Switch (ADS) technology is widely used due to its outstanding features, such as high transmittance, wide view, and weak color shift. However, the ADS technology still has intractable problems. One of the most difficult problems is the dark state light leakage under mechanical deformation which is inherent in ADS. In this paper, a novel model called Zero Light Leakage ADS (ZLL‐ADS) is proposed, which can completely eliminate the dark state light leakage even under deformation. The key point of ZLL‐ADS is the introduction of +A plate in ADS panel. The important role of +A is to compensate the phase retardation of liquid crystals to avoid dark state light leakage caused by external stress on ADS panel. By applying ZLL‐ADS technology, the product properties of BOE's ADS Pro, especially the quality of the dark picture has been greatly improved, and the advantages of ADS in high transmittance and wide view are still maintained. The compensation principle is explained theoretically and verified by 18.5 inch FHD flat and curved demoes.
46‐1: Invited Paper: Variable Refresh Rate Displays
Authors: Slavenburg Gerrit A , Janssens Marcel , Lucas Luis , Schutten Robert Jan , Verbeure Tom
Published: September 2020

A Graphics Processing Unit (GPU) renders images at a rate that varies with content properties. Displaying a sequence of GPU rendered images at fixed refresh rate causes artefacts such as stutter and tearing. Variable Refresh Rate (VRR) displays eliminate such artefacts by displaying an image as soon as the GPU renders it and then holding it till next image is available. This eliminates stutter and tearing and minimizes latency through the system. Building a Variable Refresh Rate display using an LCD panel poses several challenges for which solutions are described in this paper.
47‐1: The World Smallest OLED Microdisplay Projection Device Design Methodology
Authors: Itonaga Kazuichiro , Sudo Shoji , Nishikawa Jun , Kimura Kei , Uchiyama Hiroki , Yagi Masato , Sawano Ryosuke , Matsuyama Takatoshi , Sasaki Kouji , Itatsu Kentaro , Tsuchiya Takahiro , Nomura Yoshiyuki , Sato Yoshihisa
Published: September 2020

We developed the world smallest OLED microdisplay projection device. This device consists of just 2 parts which a high‐brightness Microdisplay based Organic Light Emitting diodes on a silicon backplane panel (M‐OLED) ( 1,000,000 [cd/m2] ) and an optimal lens (F/1.1) for the self‐emitting projection device.

This high‐ brightness M‐OLED is used 2 key technologies.

The first is a supplying the photoexitation potential to multiple emitting layers in OLED using by the new pixel transistor (Tr.) that can withstand very high voltage in 7.8 pm pixel. The second is the controlling light divergence angle from each self‐emitting pixel that made using micro optical resonance effect from cathode until anode electrode in OLED and the optimized micro lens (ML) for each pixel.

Next, we evaluated the relationship between the light divergence angle from M‐OLED and F number (Fno.) of the projection lens and we found parameters and a specific method for controlling the light efficiency of the self‐emitting projection device.

Based on the results of these fundamental studies, we established a design methodology for the self‐emitting projection device with high efficiency, and we realized the world smallest self‐emitting projection device (W 10 /D 11 /H 6 (mm)).
48‐1: Invited Paper: Next Generation Highly Efficient and Stable Phosphorescent Emitting Materials For OLEDs
Authors: Choi Byoung Ki , Cho Yong Suk , Choi Jong Won , Kwak Seung Yeon , Aratani Sukekazu , Sim Myung Sun , Koo Hyun , Kravchuk Dmitry , Im Kyu Hyun , Lee Ji Youn , Kim So Yeon , Lee Bang Lin , Kwak Yoon Hyun , Lee Sung Hun , Kim Sung Han
Published: September 2020

The efficiency of light emitting materials (dopants) is invariably compromised on moving to the red region of the spectra due to the increase of non‐radiative decay. In order to solve the above problem, we designed a new dopant, and realized organic light emitting diodes (OLEDs) with excellent performance. We achieved extremely high quantum yield of red dopant, fabricated a device with 33% higher efficiency, and improved roll‐off compared to a device with a current state‐of‐the art emitter.
48‐3: Efficiency Color‐Shift Tradeoffs in Strong‐Cavity, Top‐Emitting OLEDs
Authors: Menke S. Matthew , Erickson Nicholas C. , Rosen David A. , Brott Robert L. , Freier David G.
Published: September 2020

We show that the optical design of strong‐cavity, top‐emitting (SCTE) OLEDs is limited by tradeoffs between optical efficiency and color‐shift. Color correction technologies can be leveraged to overcome these tradeoffs, opening the design space for SCTE OLEDs.
49‐1: Fast‐Switching Electrophoretic E‐Paper with Mixture of Liquid Crystal and E‐ink for Charging and Rheological Optimizations
Authors: Yang Bo‐Ru (Paul) , Hu Wenjie , Zhang Yadi
Published: September 2020

E‐paper is an important candidate for ultra‐low‐power display of IoT environments. However, the switching speed and driving voltage are factors hindering E‐paper's prevailing. Here, we demonstrated using LC and viscosity modifier to simultaneously double the switching speed and cut down the driving voltage to half; meanwhile, the e‐paper still sustained the same contrast and bistability. This concept may pave a new route for future E‐ink research and production.
49‐4: Late‐News Paper: Prototyping of Practical e‐Tile and Estimation of its Image Impression from Distant Observers
Authors: Omodani Makoto , Masuyama Taiga , Shibata Hirohito
Published: September 2020

“e‐Tile” is introduced as a novel concept for large area displays. A typical e‐Tile configuration, in which 100 pixels are mounted on a 100 mm square board, is designed and practically prototyped. Assuming a relatively large pixel size on the electronic tile, the relationship between the viewing distance and the impression of image quality was studied by calculations and subjective evaluations.
50‐3: Electro‐Optical Transfer Characteristic, the Undervalued Display Feature
Authors: Becker Michael E.
Published: September 2020

This paper reviews specifications for (moving) image production and exchange (e.g. Rec.709, sRGB) and explains the importance of the involved nonlinear transfer functions, EOTFs, for the visual experience of the observer. The role of the inverse of the electro‐optical transfer function of the (legacy) CRT for transformation of camera signals into approximate perceptionally uniform scales is highlighted and the necessity of a non‐linear overall transfer characteristics is substantiated.
52‐2: Fast‐response Liquid Crystals for AR and Head‐Up Displays
Authors: Li Yannanqi , Huang Yuge , Ooishi Haruki , Yoshidaya Kifumi , Wu Shin-Tson
Published: September 2020

Two nematic liquid crystal mixtures with high birefringence, modest dielectric anisotropy, relatively low viscosity, and wide nematic range (‐40°C ~105°C) are developed and their physical properties evaluated. When used in reflective LCoS panels, the average response time is 2.37 ms 2π phase modulation and ~1ms for amplitude modulation. Potential applications for AR and head‐up displays are emphasized.
55‐2: Methods for Overcoming the Trade‐off between Efficiency and Lifetime of Organic Light‐Emitting Diodes: OLED Lifetime Simulation
Authors: Lee Junyoung , Han Mira , Song Woojin , Choi Kyungbok , Cho Hyunguk , Kim Yongjo
Published: September 2020

Next generation OLED displays demand high energy efficiency and high resolution, but it is a hard challenge for the OLED display industry to meet the needs for high efficiency and long lifetime simultaneously. When excitons relax to their ground state a photon is emitted; however, such excited exciton states can, on occasion, quench, leading to material degradation. In order to increase efficiency, a high concentration of excitons is needed, but this leads to more quenching events between excitons and polarons and, in turn, increased material degradation. Thus, a trade‐off exists between efficiency and lifetime, which can be alleviated by carefully optimizing the concentration and spatial distribution of excitons. In this paper, we introduce an OLED lifetime model, which we apply to overcome the aforementioned trade‐off. In order to develop the model, we first identified the key quenching factors that dominate efficiency and lifetime degradation. Based on these factors, our model can quantitatively predict device degradation. Subsequently, we can optimize the OLED stack, in terms of layer materials and thicknesses, so as to maximize efficiency, while minimizing degradation. Consequently, we demonstrate an optimized device that exhibits a 6% higher efficiency and a 2.7 times extended lifetime relative to the reference device.