bluuebunny/crossref_metadata_2025 huggingface dataset:
71‐2: Novel Optical Image Sensor Array Using LTPS‐TFT Backplane Technology as Fingerprint Recognition
Authors: Liu Bozhi , Shi Xiaoqi , Cai Shoujin , Cai Xuanxian , Lan Xuexin , Chen Guozhao , Li Junyi
Published: May 2019

A novel photo sensor by LTPS TFT backplane technology is developed, which amorphous silicon (a‐Si) layer stacks on poly silicon (p‐Si) layer to form a vertical hybrid poly and amorphous silicon PIN photo diode (HPAS‐PIN). This photo diode shows good photosensitivity as traditional a‐Si photo sensor. An optical fingerprint sensor array is realized based on the novel HPAS‐PIN photo diode and successfully capturing fingerprint image.
71‐3: Organic photolithography for displays with integrated fingerprint scanner
Authors: Malinowski Pawel E. , Ke Tung-Huei , Akkerman Hylke , Nakamura Atsushi , Shanmugam Santhosh , van Breemen Albert , Vander Velpen Dieter , Vandenplas Erwin , Hagelsieb Luis Moreno , Verscheuren Lynn , Genoe, Jan , Dehaene Wim , Kronemeier Auke Jisk , Steudel Sören , Gelinck Gerwin , Heremans Paul
Published: May 2019

Patterning organic materials by photolithography enables not only high‐resolution, side‐by‐side RGB OLED arrays, but also the introduction of organic photodetector in the same frontplane. We show patterned active matrix displays processed on flexible backplane. Furthermore, we demonstrate OPD patterning proof‐of‐concept. These are the building blocks allowing in‐cell optical fingerprint sensor.
72‐1: Invited Paper: Critical Components in Solid‐State Lighting
Authors: Sadwick Larry
Published: May 2019

Solid state lighting (SSL) has become the most preferred and efficient general lighting. This paper presents a comprehensive overview of critical components needed for SSL with the primary focus being on the critical components including those related to passive and active electronic components, circuit topologies, tradeoffs, agency and regulatory requirements.
72‐3: Invited Paper: Dynamic Color Control in Multiprimary Tunable LED Lighting Systems
Authors: Murdoch Michael J.
Published: May 2019

A framework for color control in multiprimary tunable LED lighting systems is presented. Lighting performance measures for color, circadian, and temporal characteristics are reviewed, and color system modeling and solution approaches are introduced. Example multiprimary drive intensity solutions for three commercial LED systems are optimized for different lighting performance characteristics.
75‐1: Invited Paper: Hybrid Backlight System based on Blue, Red LEDs and Perovskite Quantum Dots for Liquid Crystal Display Application
Authors: Ji Honglei , Xu Huaishu , Jiang Feng , Bai Zelong , Zhong Haizheng
Published: May 2019

This paper reports a novel backlight system for liquid crystal display by combining blue and red emissive LEDs and perovskite quantum dots embedded composite films as color converters. The backlights can realize 95% BT.2020 color gamut with a brightness of 90% relative to the backlight using blue LEDs and YAG. In comparison to the backlights using blue LEDs, perovskite quantum dots and K2SiF6:Mn4+ phosphors, this backlight system suppresses the tailing problem for dynamic dimming from red emissive K2SiF6:Mn4+ phosphors.
76‐3: Induction Heating Evaporator for the Fabrication of OLEDs
Authors: Kobayashi Shin-ichiro , Yasumatsu Mao , Fujimoto Hiroshi , Harada Kentaro , Miyazaki Hiroshi , Adachi Chihaya
Published: May 2019

We have developed a fast‐response induction heated (IH) evaporator that is capable of fabricating highly efficient organic light‐emitting diodes (OLEDs). The IH evaporator requires only 15 sec to precisely increase the deposition rate from 0.1 to 0.2 nm/s. A phosphorescent OLED with an emissive layer fabricated using the IH evaporators exhibited high external quantum efficiency of 19% at 1000 cd/m2. This novel IH evaporator technology is expected to be a powerful method for OLED production.
77‐2: Anisotropic Nano‐Structure Light Control Film
Authors: Wu Lung-Hai , Dai Yu-Jyuan , Chien Chung-Hung , Wu Pei-Hsun , Liu Pei-Yi
Published: May 2019

The Anisotropic Nano‐Structure Light Control Film was produced through the combination of Nano‐Structure Thin film and anisotropic molecular. With alignment of anisotropic molecular, light with different polarization exhibits different optical behavior, transparent or scattering. With such optical properties, the anisotropic nano‐structure light control film could be applied to enhance the visibility of transparent display, picture quality of high resolution display and ultra‐slim design,
77‐4: Large Form Birefringence Realized by Dielectric Subwavelength Grating
Authors: Quan Dunhang , Jia Hao , Li Weihao , Cheng Xing , Kwok Hoi-Sing
Published: May 2019

We present a detailed investigation of form birefringence realized by subwavelength grating based on high refractive index dielectric materials, e.g. titanium dioxide. The anticipated degree of birefringence is evaluated using Finite‐Difference Time‐Domain simulation of designed optical structure and in good accordance with the theoretical prediction. The designed subwavelength grating was fabricated using electron beam lithography and subsequent ICP dry etching technique on fused silica substrate. The artificial grating was then characterized under SEM and AFM, and a large birefringence 0.33 was obtained which can be furtherly improved with deposition process optimization.
77‐5: Late‐News Paper: Advanced phase distribution algorithm in blazed grating for continuous beam steering
Authors: Kim Young , Won Kanghee , An Jungkwuen , Choi Chil-Sung , Song Hoon , Kim Yongkyu , Jeon Myungje , Kim Sunil , Seo Wontaek , Shin Bongsu , Lee Chang-Kun , Chung Jae-Seung , Seo Juwon , Kim Yun-Tae , Sung Geeyoung , Lee Hong-Seok , Hong Sunghoon
Published: May 2019

The electrically tunable beam deflector have been researched and developed for lots of purpose. For the transmission type beam deflector, an indium‐tin‐oxide (ITO) has been developed with blazed grating patterns. The ITO layer was designed and generated on the lower substrate for transmission type beam deflector. A pixel pitch of ITO grating patterns is 6um, the electrode width is 3um with 3um spacing. With this small pixel pitch, the maximum diffraction angle is 2.541° at a wavelength of 532nm. A minimum cell gap is 2.5um for the enough 2π phase modulation with high birefringence liquid crystal which is delta n, 0.31. Total 720‐ ITO line which was patterned on the lower substrate is controlled individually by driving integrated circuit (IC) from driving module. Beam deflector driving module with driving IC is designed for continuous beam steering. Driving algorithm is developed and applied to the driving system for high angular resolution and continuous beam steering.
78‐1: Specular Reflection Measurements on Reflective E‐paper Using a Variable Aperture Source
Authors: Hertel Dirk , Kelley Edward F.
Published: May 2019

A newly‐designed variable aperture source (VAS) characterizes specular reflection from electrophoretic e‐paper displays (EPD). This 3D‐printed integrating source with a capsule‐shaped interior combines open‐port uniformity greater than 99% with a sphere‐to‐exit port size ratio below 1.6:1. Interchangeable aperture faceplates vary the source subtense between 1° and 17°. Reflectance vs. subtense curves demonstrated that EPD modulate specular reflection, and anti‐glare surfaces reduce disturbing mirror‐like reflection.
78‐2: Measurement and Evaluation of Subpixel Brightness for Demura
Authors: Feng Xiaofan
Published: May 2019

The luminance measurement accuracy of the demura system is a key factor that affects the performance of the demura. To objectively evaluate the performance of a demura system, we proposed a new evaluation method using white noise as test pattern. A test pattern was generated by adding a white noise to the gray level test pattern, the demura camera captures both the gray level pattern and the new pattern with the white noise. By calculating the subpixel brightness difference from the two captures, the subpixel brightness of this white noise pattern can be derived. The accuracy of the subpixel brightness measurement system can be evaluated with the autocorrelation of the derived subpixel brightness and the originally added random noise. The autocorrelation function characterizes both the effect of noise and spatial blur. If the display gamma is measured or known, the measured brightness can be converted to display digital counts and the root measure square error (RMSE) can be used as a metric for demura accuracy.
78‐4: An Evaluation of the Color Moving Picture Response Time for the Motion Blur by Brightness and Color of Actual Images
Authors: Jung Seung-Won , Kang Ho-Gil , Park Hye-Kyung , Lee Seok-Ryoul , Bae Jong-Uk , Yoon Soo-Yong , Kang In-Byeong
Published: May 2019

This study provides new measurement method of the motion blur close to the human visual characteristics including both brightness and color and suggests advanced index called the color MPRT which can quantify the color motion blur using primary and Macbeth colors.
80‐1: Invited Paper: Recent Development of Soluble Hole Injection Material for OLED Display
Authors: Monzen Kazuhiro , Maeda Daisuke , Higashi Masayuki , Endo Toshiyuki
Published: May 2019

We are developing the soluble hole injection materials and the inks, named ELsource® that can be used as hole injection layer in OLED display. OLED display is one of optical device. Therefore, we developed the hole injection materials with optical properties necessary for that optical device.
80‐2: Invited Paper: Ink Jet Printed Film Formation and Its Impact on OLED Device Performance
Authors: Bernatz Georg , Béalle Gaëlle , Hamburger Manuel , Tseng Hsin-Rong , Stolz Sebastian , Hayer Anna , Koenen Nils , Linge Rouven , Engel Miriam , Meyer Sebastian , Anemian Rémi , Boehm Edgar
Published: May 2019

Flat and homogeneous films by ink jet printing of organic materials are proven to be essential for OLED application. The impact of ink formulation, film thickness, pixel size, bank layout and process conditions (i.e. drying parameters) have been investigated. Their severe impact on device performance is illustrated.
81‐1: Invited Paper: Quantum Dot Phosphors Containing None of Hazardous Element; ZnTe‐Based Alloy Quantum Dots
Authors: Omata Takahisa , Tsukuda Satoshi , Asano Hiroshi
Published: May 2019

Green and narrow‐band photoluminescence at 535 nm with 30 nm of FWHM was recently achieved by Zn(Te,Se) alloy QDs, and the potential of Zn(Te,S) alloy QDs as a red phosphor was theoretically demonstrated. In this paper, the recent progress in cadmium‐free QD is reviewed focusing on ZnTe‐based alloy QDs.
P‐11: Carrier Concentration Reduction by Fluorine Doping in P‐Type SnO Thin‐Film Transistors
Authors: Wang Sisi , Lu Lei , Li Jiapeng , Xia Zhihe , Kwok Hoi Sing , Wong Man
Published: May 2019

Presently reported is the use of plasma fluorination treatment based on tetrafluoromethane to enhance the performance of a p‐type SnO thin‐film transistor (TFT). The improved performance metrics include a larger on/off current ratio, a smaller subthreshold swing and a reduction of an originally large positive turn‐on voltage. The effects of such fluorination treatment were also investigated using a host of thin‐film characterization techniques and their origin most plausibly attributed to both the significant reduction of the carrier concentration from ~2 × 1019 cm−3 to ~4.3 × 1016 cm−3 and the passivation of the defects. It is demonstrated that fluorination is an effective technique for making higher performance p‐type metal‐oxide TFTs.
P‐31: Pixel Circuit with Backgate Feedback for Deep and Rich Black Expressions on Light‐Emitting Display
Authors: Nishiyama Takayuki , Tanaka Kohei , Yamamoto Kaoru , Yamamoto Keiichi , Uchida Seiichi , Yonebayashi Ryo , Miyamoto Tadayoshi , Hosokawa Mari , Katoh Hiromi
Published: May 2019

A Pixel Circuit for light‐emitting display is presented. The circuit improves controllability of emission current by a feedback network composed of backgate of the drive transistor. The effect is adjusted by the capacitance ratio of the topgate insulator to the backgate insulator and superimposed when the networks are connected in series.
P‐38: Improved contrast ratio of TFT‐LCDs for automotive applications by optimizing retardation films and color filters
Authors: Higashi Takuya , Kira Shuichi , Niwano Yasunori , Nakanishi Kunifumi
Published: May 2019

The effects of inserted retardation films and color filters were investigated for improving contrast ratio of in‐plane‐switchingmode TFT‐LCDs. Contrast ratios with horizontally wide viewing angles corresponding to automotive applications were increased by optimizing optical characteristics of the retardation films. The effects of color filters on the contrast ratio were also investigated by comparing optical characteristics of fabricated samples.
P‐44: Long Lifetime and High Performance OLED Display with Wide Temperature Range for Automotive Application
Authors: Mizusaki Masanobu , Shibasaki Masakazu , Tsuchiya Hiroshi , Tsukamoto Yuto , Umeda Tokiyoshi , Nakamura Kei , Ohshita Toshiaki , Shimada Shinji
Published: May 2019

We have developed a long lifetime OLED display by optimizing each organic layer materials. The lifetime of the new developed blue OLED under 50 mA/cm2 driving at 85 °C was improved more than four times compared with the previously developed OLED, and achieved longer than 1,500 hours in a real use. The developed OLED display would be useful for automotive application.
P‐48: A Novel “Always‐on” Spread Spectrum Clock Technique for Reducing EMI in Display Electronics
Authors: Wei Xiangye , Ma Yuhai , Xiu Liming
Published: May 2019

Spread Spectrum Clock Generation (SSCG) is an important technique for EMI reduction. It is especially applicable for display electronics since modern society is increasingly equipped with growing number of myriad types of semiconductor display devices. To achieve the goal of lowering peak power, clock signal is intentionally “jittered”. This fact negatively impacts the clock signal integrity. For this reason, the common practice nowadays in industry is to turn off the SSCG function in normal work mode. It is only turned on when the device is actively tested for EMI influence in the lab. In this paper, a novel SSCG technique is presented. It is based on the emerging frequency synthesis technique of Time‐Average‐Frequency Direct Period Synthesis. Its aim is to maximize frequency modulation depth while precisely controls clock’s impact on system operation so that the SSCG function can be “always‐on”.
P‐66: Low Coefficient of Thermal Expansion (CTE) Display Glass Minimizes Chip on Glass (COG) Light Leakage (LL) from Chip Warp
Authors: Greene Raymond G. , Ishikawa Tomohiro , Akarapu Ravindra K.
Published: May 2019

Based on application of heated bi‐metal strip bending theory to measured chip warp on 0.5 mm thick bare Corning® EAGLEXG® Glass and Corning Lotus™ NXT Glass, low substrate CTE minimizes chip warp. Different substrates have different effective process temperatures. Chip warp is relatively insensitive to substrate Young’s modulus vs. substrate CTE.
P‐68: Research of Metal Trace Adhesion on Organic Film for Touch Panel
Authors: Ting Zeng , He-ren Gui , Zong-jie Guo , Haifeng Hu , Zhongzheng Yang , Ming Zhang , Yuan Li , Shuncheng Zhu , Youting Zhang , Dong Li
Published: May 2019

In this paper, the metal adhesion of metal trace structure and line‐width size on the organic film (insulating OC material) for touch panel was studied. At present, pure aluminum and pure copper processes can achieve the low cost and high performance requirements of the touch panel design. The influencing factors of pure aluminum trace’s adhesion on organic film were studied: ➀there was no significant difference in the comparative pull‐out force between OC and inorganic film on the 3M tape used for cross‐cut test; ➁the stress directivity of the organic film and the inorganic film was tested on silicon wafer, and the adhesion mechanism was analyzed;➂ the effect of different line widths and structure on adhesion was test; ➃in order to achieve the adhesion of metal trace in the touch panel (≧4B), it is necessary to optimize the structure designed of the organic insulating layer and SiNxOy layer.
P‐72: Nozzle Jet Printing of Organic Thin Films for Solution Process of Organic Light Emitting Diodes
Authors: An Kunsik , Kim Jong Beom , Yoon Dai Geon , Jeong Yong-Cheol , Kang Kyung-Tae
Published: May 2019

We fabricated an organic light emitting diode using poly(9‐vinylcarbazole) : tris[2‐(p‐tolyl)pyridine]iridium(III) emitting layer fabricated by nozzle jet printing. Uniform thin films were formed onto both of glass and PEN substrate. Bending test of the flexible OLEDs was also demonstrated and its performance was stably maintained until 300 cycles of bending.
P‐74: Study on the influence factors of TFT glass strength
Authors: Tian Wei , Zhang Zhihai , Duan Xianxue , Zhang Jun , Youn Yangsik , Chen Junsheng , Lee SeungKyu , Zhao Na , Yuan Miao , Shi Gaofei
Published: May 2019

The strength of TFT glass is mainly affected glass material. While reducing the film thickness, profile angle or increasing the organic film through process and material selection can reduce the sudden change of film characteristics, slow transition film stress and increase the bending resistance of TFT glass.
P‐79: Evaluation of Diffraction Induced Background Image Quality Degradation through Transparent OLED Display
Authors: Cheng Chi Jui , Huang Tzu Chin , Lin Wen Tsan , Hsieh Cheng Chih , Chen Peng Yu , Lu Peter , Lin Hoang Yan
Published: May 2019

For current transparent OLED displays, a common observation is that the background image quality is worsened when viewed through the transparent display, due to diffractive effects of the periodic grating‐like structure of the display. The aim of this work, therefore, is to develop a method to quickly and accurately evaluate the influence on the background image caused by the transparent display, as a transfer function acting on the background image, to assist in further optimization of the display structure.
P‐200: Late‐News Poster: Depth Guided and Blur Aware Optimization for Multi‐Layer Light Field 3D Display
Authors: He Yufei , Feng Yuxian , Surman Phil , Zhong Huicai , Wang Shizheng
Published: May 2019

Multi‐layer light field 3D displays are a type of computational 3D display which are gaining increasing interest for their holographic‐like effect and natural compatibility with 2D displays. However, two major shortcomings; depth limitation and multi‐layer blur are usually ignored in the traditional light field modeling and reconstruction based on liquid crystal displays (LCDs). Considering these two disadvantages, this paper proposes a depth guided and blur‐dependent optimization for multi‐layer light field displays. Different from the previous cascaded light field displays, which only use the fixed initialization plane as the depth center of the display content, the proposed method automatically chooses the best depth initialization from three different classical configurations by introducing the capture depth of camera imaging and a weighted blur factor of multi‐layer display into the optimization. Experiments demonstrate that the proposed method provides a promising advantage in visual perception of compressive light field displays with both software simulation and prototype demonstration.
P‐130: Analysis of Mechanical Stresses on Foldable Devices
Authors: Ando Nao , Hyodo Kei , Sasaki Hisao , Ota Yoshihito , Terasaki Nao
Published: May 2019

Knowledge of mechanical stresses on foldable devices is the key factor to develop them. When you study stresses, you should control motion profile then study dynamic stress. In our study, we reproduce some motions on our folding tester, compare a result of simulation and real mechanical stress.
P‐131: TCAD Modeling of Mechanical Stress for Simulation of Thin Film Transistor on Flexible Substrate
Authors: Kong sungWon , Lim Heetaek , Hoessinger Andreas , Guichard Eric
Published: May 2019

A flexible and stretchable electronic device is an inevitable component to realize wearable and foldable display device. This requires high stability of backplane device operation on flexible substrate upon external mechanical stress such as bending, stretching, and other types of deformation induced stress. Because mechanical stress effects electrical characteristics and degrades the device performance, many researchers have studied the mechanical stress behavior of thin‐film transistor devices on flexible substrates. In this work we present a process simulation model for non‐linear deformation stress. We also demonstrate the validation of the model against publish data.
P‐100: Low‐temperature Fabrication of ZnO Nanorods Using Chemical Bath Deposition Method for Sensing Application in Display
Authors: Li Chaoyang , Zhang Qiang
Published: May 2019

The highly‐orientated ZnO nanorods were synthesized by chemical bath deposition methods at 95 °C. The thicknesses of the aluminum doped ZnO, used as transparent and conductive substrates, were deposited and their optical and electrical properties were compared. The obtained aluminum‐doped ZnO films exhibits the comparable properties with ITO substrates, on which the ZnO nanorods were highly vertically grown. The uniformly ZnO nanorods showed the enhanced crystallinity with the growth time increase. The obtained ZnO nanorods are expected for sensing application in displays.
P‐101: Analyzing Acoustic Characteristics of Multi‐channel Speaker Directly Driving Flat Panel Display: Considering the Acoustic Stereo Effects
Authors: Park HyungWoo , Lee SungTae
Published: May 2019

With the technological improvements in the display industry, organic light‐emitting diode (OLED) panel manufacturers have changed screen high‐definition to simple 3D effects, augmented reality, or virtual reality. In previous research, we introduced the sound technology that vibrates the OLED panel, which name is crystal sound OLED(CSO). The difference from LCD panels, OLED panels are the simple structure, that are consists of the glass of screen and that the backside for supports. Therefore, the screen panel can take on the role of a diaphragm of an ordinary dynamic speaker. Human hearing can confirm the sound position of the three‐dimensional space by utilizing the delay difference of the sound reaching the left and right ear. If we generate these characteristics virtually, can create a 3D stereo effect. In another previous research, It is possible to create a stereo sound with multiple independent speakers. However, there is a limitation in the sound of a display speaker composed on a single panel. In this study, we analyze the acoustic characteristics of a flat speaker to realize such stereophonic sound and improve sound quality.
P‐108: Oxide Thin Film Transistors Integrated DC‐DC Converter with High Efficiency for Passive RFID Tag
Authors: Lei Tengteng , Liao Congwei , Huang Jie , Yang JiWen , Zhang Shengdong
Published: May 2019

In this work we present a DC‐DC converter based on metal oxide thin film transistors (TFTs) for passive radio frequency identification (RFID) tags. To increase the voltage conversion ratio, the cross‐coupled structure with positive feedback from adjacent stages is proposed. Compared with conventional DC‐DC converter with separation block, the proposed circuit features the decreased threshold voltage drop, the reduced on‐resistance of switch transistor, the improved driving capability and the increased power efficiency. The simulated results reveal that the output voltage and maximum power efficiency for proposed two‐stage DC‐DC converter are 16.6 V and 52% at a output current of 550 µA, which are 12.6 V and 42% at a output current of 250 µA for conventional designs.
P‐123: Hybrid Full Color Micro‐LED Displays with Quantum Dots
Authors: Wei Feng , Li Shang , Bai Xue , Liu Zhaojun
Published: May 2019

We propose a full color displays with high brightness blue Micro‐LED array, using red and green photoluminescence quantum dot as the color conversion material, and successfully begin this study with using a Mini‐LED array to excite red and green quantum dot to form a red and green picture.
P‐144: High Luminous Efficacy White OLED for Lighting
Authors: Huang Chen-Chao , Wu Sheng-Fan , Fung Man-Keung
Published: May 2019

This paper will discuss a specially designed thermally activated delayed fluorescent (TADF) exciplex host to achieve white OLEDs with luminous efficacy (LE) of 164 lm W−1 with using out‐coupling techniques. Before applying light extraction techniques, a forward‐viewing power efficiency of 75 lm W−1 was obtained at a brightness of 150 cd m−2. The white OLED exhibits an efficacy of 63 lm/W and external quantum efficiency (ηext) of ∼22%, with a CIE (x,y) coordinates of (0.40, 0.48) at a brightness of 1000 cd/m2. We anticipate that our findings have great potential to boost the LE of OLEDs, and more importantly, fulfill the power efficacy requirement for lighting applications.
P‐161: The Investigation about Influence of Polyimide on Around Mura
Authors: Zhao Yongchao , Zhang Yu , Song Yanjun , Chi Baolin , Hsieh Chung-Ching , Chiu Chung-Yi
Published: May 2019

We studied the formation mechanism of around mura, which occurred during the HTHHO test (high temperature and humidity operation ). In this paper, We find that coating properties of PI are important factors affecting around mura . According to our experiments, PI coating accuracy extending\ Increasing the PPO (PI prebake oven) temperature and decreasing the PI thickness can reduce the ratio and degree of around mura effectively.
P‐167: Pre‐transitional Effect of Antiferroelectric Liquid Crystals and Their Photonic Applications
Authors: Feng Zhengyu , Chiang Po-Jen , Chen Shu-jhih , Lee Chia-yu , Ishikawa Ken
Published: May 2019

A phase‐only modulation mode based on the pre‐transitional effect of antiferroelectric liquid crystal(AFLC) is demonstrated. This field‐induced biaxiality enables 2π phase modulation of 632.8nm light and keeps the polarization state invariant for TE or TM light. Based on this, a switchable phase grating is constructed and the maximum diffraction efficiency of 37.0% is achieved at 1.8V/µm for the ±1st order.
P‐170: Circularly Polarized Electroluminescence in a Low Molecular Weight Mesogenic Compound
Authors: Lee Dong-Myung , Woo Jong-Ha , Jeong Seung-Hyun , Seo Jeong-Dae , Choi Hyun-Chul , Yu Chang-Jae , Kim Jae-Hoon
Published: May 2019

We studied the properties of circularly polarized OLEDs based on twisted low molecular weight emitting compound with mesogenic phase. Through quenching the spin‐coated compound after heating at its mesogenic phase, twisted configuration and circularly polarized emission are obtained.
P‐171: The Mechanism of the OLED Reliability Failure for Thin Film Encapsulation in Lateral Direction
Authors: Wang Tao , Sun Tao , Xie Chunyan , Wang Youwei , Qin Chengjie , Zhang Ziyu , Zhou Weifeng , Zhang Song
Published: May 2019

The failure mechanism for the thin film encapsulation (TFE) structure in the lateral direction was studied. A series of lateral distances for TFE was achieved by the development of the low‐temperature etching process. Taking the distance and the adhesion force into consideration, a failure model was established.
P‐172: Novel Sterically Bulky Hole‐Transporters Realizing Enhanced Operation Lifetime in TADF OLEDs
Authors: Sasabe Hisahiro , Kamata Takahiro , Ito Nozomi , Igarashi Masahiro , Kido Junji
Published: May 2019

We developed a series of sterically bulky hexaphenylbenzene‐based hole‐transporters named 4DBTHPB and 4DBFHPB with deep Ip of –5.8 eV and high ET of 2.7 eV. By using 4DBFHPB as a hole‐transporter, we realized a highly efficient and stable green TADF OLED exhibiting maximum external quantum efficiency of 19.4 % and operation lifetime at 50 % (LT50) of approximately 24,000 hrs at an initial luminance of 1000 cd m–2. Further, we investigated the effect of these hole‐transporters in sky‐blue TADF OLEDs.
P‐179: Optics of Curved OLEDs
Authors: Cyue Zih-Rou , Lee Wei-Kai , Yu Li-Yu , Su Guo-Dung , Wu Chung-Chih
Published: May 2019

Although flexible OLEDs are often used in curved formats and their optics would differ from planar OLEDs, their impacts on OLED emission characteristics are not carefully studied before. Here we investigate optics of curved OLEDs by both optical simulation and experiments and reveal their implications to real flexible OLED applications. We demonstrate light extraction efficiency can be substantially enhanced, or emission profile and viewing angles can be varied, with curved OLEDs in some formats. This may be of use for some special lighting and display applications.
P‐183: Ag:WO3 Cermet as a Stable Cathode with Low and Tunable Reflectance for Top‐Emission OLED
Authors: Caron Baptiste , Maindron Tony , Racine Benoit , Meunier-Della-Gatta Sylvia , Vaxelaire Nicolas , Quesnel Etienne
Published: May 2019

We present a new cermet cathode Ag:WO3 for top‐emission OLEDs. The silver nano‐particles in the layer lead to a tunable plasmonic resonance from 500 to 800 nm which limits ambient light reflection. Furthermore, the introduction of WO3 in the cathode improves the lifetime of the device.
P‐185: Highly Efficient and Long Lifetime Bipolar Host Material for Red Phosphorescent Organic Light‐Emitting Diodes Using Benzocarbazole and Diphenyltriazine Derivatives
Authors: Park Yun Hwan , Lee Kyung Hyung , Lee Jun Yeob
Published: May 2019

Red phosphorescent organic light‐emitting diodes (phOLEDs) can achieve 100% internal quantum efficiency by harvesting both singlet and triplet excitons through spin orbit coupling. To improve the external quantum efficiency (EQE) and device lifetime, many molecular designs of bipolar hosts with appropriate energy band gap and triplet energy were studied in doping system phOLEDs. Two kinds of bipolar hosts were synthesized by combining benzocarbazole hole type donor and diphenyltriazine electron type acceptor to achieve relatively low triplet energy for red phOLEDs. Two hosts with the benzocarbazole and diphenyltriazine linked through para and meta positions of the phenyl unit proved a triplet energy of 2.52 eV and bipolar carrier transport properties. The band gap of the emitters between highest energy occupied molecular orbital (HOMO) and lowest energy occupied molecular orbital (LUMO) is 2.89 eV and 2.83 eV, while the EQE was 21.7% and 20.7% respectively, as a result of doping with red emitter. It was confirmed that life time was 30 times longer than that of general 4,4′‐bis(n‐carbazolyl)‐1,1′‐biphenyl (CBP) host at 5000 cd/m2.
P‐191: Dielectric‐Metal‐Dielectric Structure and Its Application as Top Cathode in Highly Efficient Top‐Emitting WOLEDs
Authors: Huang Qingyu , Liu Xiaoyun , Yan Huajie , Jiao Zhiqiang , Yang Jin , Yuan Guangcai
Published: May 2019

Top emitting white organic light emitting diodes (WOLEDs) hold great promise for high brightness and high resolution active matrix OLED displays. One key challenge of high‐performance top emitting WOLEDs is the availability of top electrodes with superior optical, electrical properties. Herein, we demonstrate the application of the dielectric/metal/dielectric structure consisting of a titanium dioxide WO3/Ag/WO3 stack as the transparent top cathode on organic light‐emitting diodes (OLEDs). Better performance than that of the normally used semi‐transparent Mg:Ag cathode was obtain from the top emitting WOLEDs with the DMD cathode. Moreover, DMD device not only show bright emission similar to that of the IZO cathode device, but also enduring no damage in the device fabrication.
P‐211: Late‐News Poster: Extremely Smooth Electrospun Ag Fiber Electrodes Embedded in PVB Flexible Substrate for Organic Light‐Emitting Diodes
Authors: Kim Enjung , Choi Junhee , Ju Byeong-Kwon
Published: May 2019

We purposed to fabricate an organic light‐emitting device (OLED) using an Ag fiber electrode embedded in a polyvinyl butyral (PVB) substrate. Since the electrode is embedded in a flexible polymer substrate, the surface roughness is very low. Moreover, since the depth of the electrode can be freely adjusted, the resistance can be very low without decreasing the transmittance. As a result, we demonstrated that a OLED with external quantum efficiency of 10 % was successfully fabricated.
P‐214: Late‐News Poster: Enhanced Out‐coupling Efficiency of Organic Light‐emitting Diodes Using a Corrugated Microcavity Structure
Authors: Hwang Ha , Choi Junhee , Lee Ju Sung , Park Young Wook , Ju Byeong-Kwon
Published: May 2019

In this study, organic light‐emitting diodes with enhanced out‐coupling efficiency and suppressed viewing angle dependence were demonstrated by the novel structure of a corrugated microcavity. The corrugated nanopatterned Ag layer were fabricated through a laser interference lithography (LIL) process. The corrugated Ag film increased the EL intensity and suppressed viewing angle dependence.
Stable Li‐Metal Deposition via a 3D Nanodiamond Matrix with Ultrahigh Young's Modulus
Authors: Zhang Weidong , Fan Lei , Tong Zheming , Miao Jiazhi , Shen Zeyu , Li Siyuan , Chen Fang , Qiu Yongcai , Lu Yingying
Published: May 2019

The practical usage of high‐energy lithium metal batteries remains a great challenge mainly due to the formation of uneven lithium deposition and huge volume fluctuation on the anode side, which increases the potential risks of a cell short‐circuit. Herein, a nanodiamond‐Li composite anode (ND‐Li) is created using a facile thermal infusion strategy, which can mechanically confine active Li‐metal in the ND matrix and minimize the electrode volume change during electrochemical cycling with high areal capacities. The geometrically restrictive ND matrix with ultrahigh modulus can deform the uneven lithium deposition mechanically and confine the deposition to the ND matrix. Owing to the 3D rigid skeleton, low stripping/plating overpotential (≈60 mV) can be achieved for a ND‐Li anode under a high current density of 10 mA cm−2, whereas the overpotential of a bare Li foil anode is almost seven times larger than the ND‐Li matrix. When a ND‐Li anode pairs with a S cathode, a high capacity of 607.3 mAh g−1 at 1 C and stable long‐term cyclability over 500 cycles can be achieved.
Full‐scale experimental assessment of new connection for columns in vertically mixed structures
Authors: Bahri Farzad , Kafi Mohammad Ali , Kheyroddin Ali
Published: May 2019

More stiffness of concrete frames on one hand and fewer weight of steel frames on the other hand motivates using a composite system so called vertically mixed structures. The reinforced concrete and steel frames are connected together at a story called transition story. A major challenge for the designers is the connection columns in the transition story for proper transferring of efforts and preventing stress concentration phenomenon. There are some suggestions, in the literature, to build a transition composite column instead of constructing a local connection. Four full‐scale specimens of three connection types are constructed and tested experimentally under cyclic load to investigate hysteresis characteristics, failure mechanism, deformability, and energy dissipation capacity of the model. A novel through bolt lap connection adapted from concrete‐filled tube (CFT) column is proposed. Finally, backbone curves of proposed column for more accurate seismic studies are presented. No evident sign of local failure is observed in the proposed connection. Placing the steel around the reinforced concrete column section prepares the maximum possible geometrical dimensions for the steel column section and the connection. The experimental results show no strength loss for the new proposed connection under two different axial loads in lateral cyclic loading up to 4% drift.
Nationally Determined Contributions: Material climate commitments and discursive positioning in the NDCs
Authors: Mills‐Novoa Megan , Liverman Diana M.
Published: May 2019

In the lead‐up to the 2015 Conference of Parties meeting in Paris, 186 countries, representing over 95% of global emissions, submitted Nationally Determined Contributions (NDCs). The NDCs outline national goals for greenhouse gas emission reductions and identify financial needs for unfolding mitigation and adaptation efforts. In this study, we review various analyses of the NDCs that cover the aggregate impact and strength of emissions reduction commitments and discuss recent literature on the adequacy and sectoral focus of the NDCs. We then argue that the NDCs are more than just goal setting reports; they are important discursive documents that are contested, negotiated, and ongoing. To supplement the existing literature, we examine the discursive narratives embedded in the NDCs from the 19 founding nations of the Climate Vulnerable Forum and the top 10 greenhouse gas emitters. Our literature review of quantitative and sectoral aspects of the NDCs highlights the inadequacy of the NDC commitments in the context of limiting warming to 2°C, discusses the uncertainties in the promised mitigation strategies, and identifies the reliance of many countries on policies such as those on forests or renewable energy. Our own analysis of the discourses in the NDCs adds critical depth by highlighting the stark contrasts in NDC discourses between North and South, as well as between historical emitters and emerging economies. These contrasts reflect deeper debates regarding justice and equity between nations within the UNFCCC negotiations.

This article is categorized under:

Climate and Development > Decoupling Emissions from Development
Revisiting the Role and Future of National Constitutions in European and Global Governance: Introduction to the Research Project
Authors: Albi Anneli , Bardutzky Samo
Published: May 2019

The Introduction provides an overview of the research project ‘The Role and Future of National Constitutions in European and Global Governance’, which was funded by a five-year grant of 1.2 million EUR, awarded by the European Research Council (ERC). The research findings are published in the present two-volume book, containing national reports from twenty-eight EU Member States, and a twenty-ninth report – focusing on constitutional reforms related to global governance – from Switzerland. The reports are based on the project Questionnaire. The main themes are threefold: (a) constitutional amendments with a view to EU membership; (b) constitutional adjudication at the national level regarding EU measures such as the Data Retention Directive, European Arrest Warrant and ESM Treaty; and (c) novel challenges that are increasingly highlighted in the wider context of global governance (i.e. beyond the classic international treaties that advance human rights, peace and environmental protection) in relation to democratic participation, judicial review and the rule of law. Whilst in the mainstream discourse national constitutions have typically been approached from a top-down perspective and with a focus on sovereignty, the present bottom-up study allows for the perspective to be broadened by looking at how EU and transnational law have affected constitutional cultures in specific areas, such as fundamental rights protection, rule of law safeguards and constitutional review. The reports are accompanied by a linked book with a Comparative Study, which divides the constitutional systems of the EU Member States into three broader constitutional cultures and identifies overarching trends, changes and processes regarding constitutionalism. The comparative research findings are briefly outlined in the Introduction, inviting discussion on what ought to be the direction of travel for national, comparative European, EU and global constitutionalism. The project and the reports explore constitutional developments up until 2014-15 and do not address the more recent illiberal trends.
The Constitution of Croatia in the Perspective of European and Global Governance
Authors: Goldner Lang Iris , Đurđević Zlata , Mataija Mislav
Published: May 2019

The report from the newest EU Member State – Croatia – explains that the constitutional system represents a break from the former socialist system, where the Constitution had been more ‘political’ and not directly applied in practice. The constitutional order is highly influenced by the German constitutional tradition, and the Constitutional Court often cites the German Constitutional Court. The Constitution has been amended with regard to the EU in a very extensive manner. No significant constitutional issues have arisen with regard to EU or international law. By way of some limited exceptions, trade unions and individuals unsuccessfully sought to contest austerity measures required as part of the EU Council’s excessive deficit proceedings in the Constitutional Court. The Constitutional Court has additionally adjudicated questions on whether referendums regarding privatisation of certain public services are permissible, given that the referendum outcome could lead to incompatibility with EU law. The increased cost of water in relation to a relevant EU Directive was the object of the first reference for a preliminary ruling from Croatia. With regard to the European Arrest Warrant (EAW), some legislative guarantees (such as the statute of limitations) were removed from an implementing law following severe criticism and the threat of financial sanctions from the European Commission. The move through the EAW system towards in absentia judgments has also led to some debate, given the historical experience with a high number of in absentia judgments during the 1991–1995 war and the subsequent finding that a vast majority of these trials had violated fair trial rights.
The Belgian Constitution: The Efficacy Approach to European and Global Governance
Authors: Popelier Patricia , Van de Heyning Catherine
Published: May 2019

The Belgian Constitution dates back to 1831 but became more prominent with the introduction of the Constitutional Court in 1980. While initially tasked with adjudication of federal competences, the Court gradually turned into a fundamental rights court. The protection of fundamental rights is predominantly based on the ECHR. The Belgian constitutional system demonstrates a singular openness towards international influences and, in particular, the European integration project. A monist approach, adopted by the Supreme Court in 1971, ensures the smooth implementation and priority of international and EU law, whereas only few instruments exist to temper their impact on constitutional values and fundamental rights or to ensure legitimacy. The disintegration of the Belgian State weakened the concept of national sovereignty, referendums for the approval of treaties are unconstitutional, and ratification of a treaty is not subjected to specific requirements other than a majority vote in Parliament. Overall, the Belgian Constitutional Court gives evidence of a strikingly Europe-friendly attitude, in line with attitudes at the political level and in society. Consequently, both the Europeanisation of constitutional rights and the implementation of international and EU law that potentially restrict fundamental rights, hardly trigger public debate. This approach, however, may change in the future. Surveys demonstrate that confidence in the European integration project is in decline amongst young adults. In 2016, after the submission of this paper, the Constitutional Court for the first time adhered to the constitutional identity doctrine, so far without further consequences. Also, it can be expected that the Constitutional Court would not easily accept external interference that would upset the delicate linguistic balances that are crucial for the stability of a divided Belgian State. Already, (Flemish) political parties are hesitant to join international treaties that they perceive as a threat to such balances.
The Role of the Danish Constitution in European and Transnational Governance
Authors: Krunke Helle , Baumbach Trine
Published: May 2019

The Danish Constitution originates from 1849. Its human rights catalogue, which stems from 1953, is described in the report as old and not very comprehensive; in many cases the ECHR goes further in protection. Denmark does not have a constitutional court, and courts take a deferential approach to judicial review; up until 2015, only one Act had been annulled on the grounds of unconstitutionality. The Danish concept of democracy builds on a strong Parliament and reluctant courts, which are careful not to act in a ‘political’ manner. Regarding constitutional amendments, the Danish Constitution has not undergone changes in relation to EU membership. This is partly attributed to the difficult amendment procedure involving two (different) referendums and a high turnout requirement. In practice, Danish parliamentary control over Government in EU decision-making has widely come to be regarded as one of the strongest in Europe. However, with regard to domestic implementation, in 2015 Parliament expressed concern that the executive had implemented EU directives by administrative acts in nine out of ten cases. Other constitutional issues that have arisen include considerable debate regarding the Laval line of cases, given the strong Scandinavian welfare system and the tradition of ordinary collective agreements. Another concern that has been raised by the Danish Supreme Court is that the use of teleological interpretation in a number of ECJ cases has affected legal certainty and foreseeability, which are at the centre of the Danish understanding of the rule of law.
Matter dependence of the four-loop QCD cusp anomalous dimension: from small angles to all angles
Authors: Brüser Robin , Grozin Andrey , Henn Johannes M. , Stahlhofen Maximilian
Published: May 2019

Abstract

We compute the fermionic contributions to the cusp anomalous dimension in QCD at four loops as an expansion for small cusp angle. As a byproduct we also obtain the respective terms of the four-loop HQET wave function anomalous dimension. Our new results at small angles provide stringent tests of a recent conjecture for the exact angle dependence of the matter terms in the four-loop cusp anomalous dimension. We find that the conjecture does not hold for two of the seven fermionic color structures, but passes all tests for the remaining terms. This provides strong support for the validity of the corresponding conjectured expressions with full angle dependence. Taking the limit of large Minkowskian angle, we extract novel analytic results for certain terms of the light-like cusp anomalous dimension. They agree with the known numerical results. Finally, we study the anti-parallel lines limit of the cusp anomalous dimension. In a conformal theory, the latter is proportional to the static quark-antiquark potential. We use the new four-loop results to determine parts of the conformal anomaly term.
Gauge theory and boundary integrability
Authors: Bittleston Roland , Skinner David
Published: May 2019

Abstract

We study the mixed topological/holomorphic Chern-Simons theory of Costello, Witten and Yamazaki on an orbifold (Σ×ℂ)/ℤ2, obtaining a description of lattice integrable systems in the presence of a boundary. By performing an order ℏ calculation we derive a formula for the the asymptotic behaviour of K-matrices associated to rational, quasi-classical R-matrices. The ℤ2-action on Σ × ℂ fixes a line L, and line operators on L are shown to be labelled by representations of the twisted Yangian. The OPE of such a line operator with a Wilson line in the bulk is shown to give the coproduct of the twisted Yangian. We give the gauge theory realisation of the Sklyanin determinant and related conditions in the RTT presentation of the boundary Yang-Baxter equation.