Academic literature on the topic 'OLEDs'
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Journal articles on the topic "OLEDs"
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Odedara, Nisha, Niteen Borane, Rahul Patel, and Rajamouli Boddula. "A Review on the Milestones of Blue Light-Emitting Materials in India." Organic Materials 5, no. 01 (January 2023): 1–20. http://dx.doi.org/10.1055/s-0042-1757980.
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Since 1987 in the field of optoelectronics, organic light-emitting diodes (OLEDs) have secured their position because of their extreme use in panels of lighting applications such as TV and smartphone displays. At present, OLEDs are at top-notch position in the lighting market for their promising features. The field of OLEDs is rapidly growing day by day in academia and industry due to the success of OLEDs in the form of excellent efficiency, feasible methods, excellent lifetime, color purity, and superb device architecture. As a result, OLEDs are new profitable leading devices of the 21st century. However, the OLED industry has evolved in optoelectronics in the last 30 years and is advancing rapidly just because of the development in OLED materials (fluorescent, phosphorescent, thermally activated delayed fluorescent, and blue light-emitting materials). Blue light-emitting materials have achieved incredible popularity nationally and internationally. At the international level, USA, Japan, Korea, and Germany are at the top of the list in the production of OLEDs. India has also seen rapid progress in OLED development in the last 12 years and details of research in blue OLEDs by key players of India are involved in this report.1 Introduction1.1 OLED Construction1.2 Working of OLED2 OLED Development2.1 Historical Background of OLED2.1.1 International Status2.1.2 National Status3 Progress of Blue Emitters in India4 Present Scenario of Blue OLEDs5 Conclusions and Outlook
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Xu, Ting, Kele Zhao, Haojie Dong, and Lingqiang Meng. "P‐15.1: Optical Modeling Simulation and Experiment of Narrow‐Band Emission Tandem OLEDs, Solution‐Processed Hole Injection/Transport OLEDs and Organic Light Emitting Transistors." SID Symposium Digest of Technical Papers 55, S1 (April 2024): 1420–25. http://dx.doi.org/10.1002/sdtp.17385.
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This study shows the investigations of Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials and solution‐processed holes injection/transport layers (HITLs) in organic light‐emitting diodes (OLEDs), while extending to Organic Light Emitting Transistors (OLETs). Firstly, we explore TBN‐TPA, a blue MR‐TADF material, in single‐unit and tandem OLEDs via optical simulation. The tandem architecture enhances color purity, achieving a narrow full width at half maximum down to 24 nm, thus meeting BT 2020 standards. This marks the first instance of tandem OLEDs improving both efficiency and color performance of a multi‐resonance TADF emitter. Concurrently, we investigate the regulation of solution‐processed HITL compositions in OLEDs, aiming to improve charge injection and optical waveguiding. The adoption of solution‐processed HITLs reduces the turn‐on voltage and enhances power efficiency by 8.81% at a brightness of 5000 cd/m2 compared to vacuum‐deposited HITLs. By adjusting the composition of solution‐based PEDOT:PSS/TAPC as HITL, we effectively mitigate hole injection barriers and improve surface morphology, establishing an optical waveguide within the OLED structure. This holistic investigation employs optical simulation to advance high‐performance and cost‐effective OLEDs and OLETs for lighting and displays.
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Berry, Matthew, and Stuart Thomson. "Photoluminescence and Electroluminescence Confocal Imaging of an OLED." ECS Meeting Abstracts MA2024-01, no. 31 (August 9, 2024): 1553. http://dx.doi.org/10.1149/ma2024-01311553mtgabs.
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In recent years organic light-emitting diodes (OLEDs) have become one of the leading technologies for full-colour display panels in high-end smartphones and televisions. This rapid growth in use has occurred because OLEDs offer an all-around superior performance to liquid crystal displays (LCDs). For example, they are thinner, lighter, more flexible, less power consumptive, and brighter. When new OLEDs are developed, the optoelectronic properties of individual components and the complete device can be characterised using photoluminescence (PL) and electroluminescence (EL) spectroscopy. In this poster presentation, we use a confocal Raman microscope to characterise and spatially resolve the optoelectronic properties of a fabricated OLED device with four imaging modalities: PL, EL, time-resolved PL (TRPL), and time-resolved EL (TREL). Using a confocal microscope to characterise an OLED's spectral and time-resolved properties provides much greater detail than bulk measurements. Figure 1
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Sheng, Hao. "Study on Working Principle, Structure, Enhancement Technology, and Applications of Organic Light-emitting Diodes." Highlights in Science, Engineering and Technology 27 (December 27, 2022): 302–10. http://dx.doi.org/10.54097/hset.v27i.3771.
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Nowadays OLEDs outperform normal LEDs in terms of ease-processing, flexibility, skinniness, lightweight, and manufacturing cost. However, there is still much room to improve in terms of materials, efficiency, and longevity. Improving the performance of OLEDs has become the most popular research area. In order to make full use of excitons after recombination of carriers, phosphorescent OLED has been proposed. Recently, there is a gradual trend for phosphorescent OLEDs to be replaced by TADF OLEDs, as these TADF OLEDs can not only exhibit 100% internal quantum efficiency and are cheap to produce because they do not contain precious metals. At the same time, TADF OLEDs are considered to have more room for development especially in the aspect of longevity and color. Therefore, more researches are still needed to solve the blue OLED problem because compared to other colors, such as red and green OLEDs, blue OLEDs still have a big gap in stability and efficiency. In this work, the history of OLEDs, their working principle, the technologies that have been improved, and the cross-border derivative applications were studied.
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Naqvi, Syed, Mirza Baig, Tanveer Farid, Zahid Nazir, Syed Mohsan, Zhe Liu, Wanqing Cai, and Shuai Chang. "Unraveling Degradation Processes and Strategies for Enhancing Reliability in Organic Light-Emitting Diodes." Nanomaterials 13, no. 23 (November 25, 2023): 3020. http://dx.doi.org/10.3390/nano13233020.
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Organic light-emitting diodes (OLEDs) have emerged as a promising technology for various applications owing to their advantages, including low-cost fabrication, flexibility, and compatibility. However, a limited lifetime hinders the practical application of OLEDs in electronic devices. OLEDs are prone to degradation effects during operation, resulting in a decrease in device lifetime and performance. This review article aims to provide an exciting overview of OLED degradation effects, highlighting the various degradation mechanisms. Subsequently, an in-depth exploration of OLEDs degradation mechanisms and failure modes is presented. Internal and external processes of degradation, as well as the reactions and impacts of some compounds on OLED performance, are then elucidated. To overcome degradation challenges, the review emphasizes the importance of utilizing state-of-the-art analytical techniques and the role of these techniques in enhancing the performance and reliability of OLEDs. Furthermore, the review addresses the critical challenges of lifetime and device stability, which are crucial for the commercialization of OLEDs. This study also explores strategies to improve OLEDs’ lifetime and stability, such as using barrier layers and encapsulation techniques. Overall, this article aims to contribute to the advancement of OLED technology and its successful integration into diverse electronic applications.
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Gao, Wei, Jianyun Wang, Yepeng Xiang, Jinghua Niu, Long Chen, and Bong-Geum Lee. "29‐2: Distinguished Paper: High Efficiency and High Color Purity Deep‐Blue Organic Light‐Emitting Diodes with Blue Index >500." SID Symposium Digest of Technical Papers 55, no. 1 (June 2024): 369–72. http://dx.doi.org/10.1002/sdtp.17534.
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Thermally activated delayed fluorescent (TADF) and phosphorescent blue organic light‐emitting diodes (OLEDs) have been developed to overcome the relatively low triplet exciton utilization of traditional fluorescent OLEDs. However, broad emission spectra originating from charge transfer process limits the commercial application of such blue OLEDs. Herein, an effective phosphor‐sensitized fluorescent (PSF) OLED device structure was designed. PSF OLED exhibited a maximum blue index (BI) of 508 cd/A/CIEy with CIEy of 0.060, which has been the highest efficiency result reported for PSF deep‐blue OLEDs. Impressively, the sensitized OLEDs maintained blue index of 407 cd/A/CIEy, narrow emission spectra (FWHM = 17 nm) and high color purity (CIEy = 0.046), revealing the attractive technical advantages and commercial application potential.
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Zhang, Jialin. "Recent research on the status and advances of OLED." Applied and Computational Engineering 25, no. 1 (November 7, 2023): 219–26. http://dx.doi.org/10.54254/2755-2721/25/20230767.
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Organic Light-Emitting Diodes (OLEDs) have already been a prominent display technology in various applications for many decades, ranging from smartphones and televisions to wearable devices and lighting. It is important to understand the current state of OLED research in order to assess its progress, identify challenges, and explore more potential ways for further development. In this paper, the significance and widespread adoption of OLED technology are briefly introduced, and its advantages over traditional display technologies are highlighted. The paper then provides a concise overview of the major components and working principles of OLEDs without delving into basic notions. The paper discusses both small molecule OLEDs (SMOLEDs) and polymer OLEDs (POLEDs), emphasizing their unique structure, characteristics and properties. Different strategies employed to enhance OLED performance is investigated, including the regulation of band gaps that influence the efficiency and brightness. This paper also focuses on the evaluation of device reliability and stability aspects. The techniques and materials employed in studies related to OLED development are also discussed with many searched experimental data and ongoing research activities. Furthermore, the research content covered the aspects of recent commercial advancements in OLED technology, such as Active matrix OLEDs (AMOLED) and Passive matrix (PMOLED). The review provides a guideline for researchers, industry professionals, and enthusiasts to better understand the OLED technology into its details, potential, and the areas that require further exploration.
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Wang, Dongxiang, Jacqueline Hauptmann, and Christian May. "OLED Manufacturing on Flexible Substrates Towards Roll-to-Roll." MRS Advances 4, no. 24 (2019): 1367–75. http://dx.doi.org/10.1557/adv.2019.62.
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ABSTRACTLarge area lighting OLEDs manufactured in a Roll-to-Roll (R2R) fashion enable the well-longed production capability with considerably high throughput based on flexible substrates, hence largely reduced OLED manufacturing cost. This paper will outline the present status of R2R OLED fabrication on ultra-thin glass with the focus on transparent OLED devices and how to perform segmentation by printing of silver- and dielectric pastes. Ultra-thin glass (UTG) is laminated on a PET film to avoid fabrication interruptions when glass cracks occur during the Roll-to-Roll process. The R2R fabricated flexible OLEDs also show key-values comparable to conventional OLEDs fabricated on small rigid glass in lab-scale.
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Zheng, Luping, Jiaju Xu, Yaomiao Feng, Haiquan Shan, Guojia Fang, and Zong-Xiang Xu. "Green solvent processed tetramethyl-substituted aluminum phthalocyanine thin films as anode buffer layers in organic light-emitting diodes." Journal of Materials Chemistry C 6, no. 42 (2018): 11471–78. http://dx.doi.org/10.1039/c8tc00960k.
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Green solvent processable tetramethyl-substituted Al(iii) phthalocyanines were employed as anodic buffer layers of OLEDs, achieving the enhanced OLED performance and durability compared with those of OLEDs using PEDOT:PSS.
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Sahu, Lokesh Kumar, and Vaishali Soni. "OLED: New Generation Display Technology." Journal of Ravishankar University (PART-B) 35, no. 1 (March 8, 2022): 1–8. http://dx.doi.org/10.52228/jrub.2022-35-1-1.
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As time gets advanced multiple progressions have happened in the field of display devices. In this field first came a small LED then after CRT (Cathode Ray Tube) which is used in present days but due to its heaviness, we do not carry it from one place to another. Then after came LCD (Liquid Crystal Display), the problem of bulkiness and required large area overcome by LCD, the only problem with LCD is that it cannot see a clear picture from different angles. LCD is a lightweight and flexible plastic substrate. After all these innovations OLED came and OLED beat all issues of LCD and CRT. OLED is light and slim in design, it does not require any kind of backlight, OLEDs are self-luminous. Polymers are using to fabricate OLEDs or unlike LCDs small molecules in the flat panel zone. It has low power consumption (only 2-10 volts) also OLEDs has a wide viewing angle (up to 160 degrees). The applications of OLEDs in electronics are on the increase on daily basis from camera to cell phones to OLED televisions.
Dissertations / Theses on the topic "OLEDs"
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Schwab, Tobias. "Top-Emitting OLEDs." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-157992.
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In the last decades, investigations of organic light-emitting diodes (OLEDs) have tackled several key challenges of this lighting technology and have brought the electron to photon conversion efficiency close to unity. However, currently only 20% to 30% of the photons can typically be extracted from OLED structures, as total internal reflection traps the major amount of the generated light inside the devices.
This work focuses on the optimization of the optical properties of top-emitting OLEDs, in which the emission is directed away from the substrate. In this case, opaque materials, e.g. a metal foil or a display backplane can be used as substrate as well. Even though top-emitting OLEDs are often preferred for applications such as displays, two main challenges remain: the application of light extraction structures and the deposition of highly transparent materials as top electrode, without harming the organic layers below. Both issues are addressed in this work.
First, top-emitting OLEDs are deposited on top of periodically corrugated light outcoupling structures, in order to extract internally trapped light modes by Bragg scattering and to investigate the basic scattering mechanisms in these devices. It is shown for the first time that the electrical performance is maintained in corrugated top-emitting OLEDs deposited on top of light extraction structures. Furthermore, as no adverse effects to the internal quantum efficiency have been observed, the additional emission from previously trapped light modes directly increases the device efficiency. It has been proven that the spectral emission of corrugated OLEDs is determined by the interference of all light modes inside the air light-cone, including the observation of destructive interference and anti-crossing phenomena. The formation of a coherently coupled mode pair of the initial radiative cavity mode and a Bragg scattered mode has been first observed, when grating structures with an aspect ratio > 0.2 are applied. There, the radiative cavity mode partially vanishes. The observation and analysis of such new emission phenomena in corrugated top-emitting OLEDs has been essential in obtaining a detailed insight on fundamental scattering processes as well as for the optimization and control of the spectral emission by light extraction structures.
Second, the adverse impact of using only moderately transparent silver electrodes in white top-emitting OLEDs has been compensated improving the metal film morphology, as the organic materials often prevent a replacement by state-of-the-art electrodes, like Indium-tin-oxide (ITO). A high surface energy Au wetting layer, also in combination with MoO3, deposited underneath the Ag leads to smooth, homogeneous, and closed films. This allows to decrease the silver thickness from the state-of-the-art 15 nm to 3 nm, which has the advantage of increasing the transmittance significantly while maintaining a high conductivity. Thereby, a transmittance comparable to the ITO benchmark has been reached in the wavelength regime of the emitters. White top-emitting OLEDs using the wetting layer electrodes outperform state-of-the art top-emitting devices with neat Ag top electrodes, by improving the angular colorstability, the color rendering, and the device efficiency, further reaching sightly improved characteristics compared to references with ITO bottom electrode. The enormous potential of wetting layer metal electrodes in improving the performance of OLEDs has been further validated in inverted top-emitting devices, which are preferred for display applications, as well as transparent OLEDs, in which the brittle ITO electrode is replaced by a wetting layer electrode.
Combining both concepts, wetting layer electrodes and light extraction structures, allows for the optimization of the grating-OLED system. The impact of destructive mode interference has been reduced and thus the efficiency increased by a decrease of the top electrode thickness, which would have not been achieved without a wetting layer. The optimization of corrugated white top-emitting OLEDs with a top electrode of only 2 nm gold and 7 nm silver on top of a grating with depth of 150 nm and period of 0.8 µm have yielded a reliable device performance and increased efficiency by a factor of 1.85 compared to a planar reference (5.0% to 9.1% EQE at 1000 cd/m2). This enhancement is comparable to common light extraction structures, such as half-sphere lenses or microlens foils, which are typically restricted to bottom-emitting devices. Overall, the deposition of top-emitting OLEDs on top of light extraction structures finally allow for an efficient extraction of internally trapped light modes from these devices, while maintaining a high device yield.
Finally, the investigations have resulted in a significant efficiency improvement of top-emitting OLEDs and the compensation of drawbacks (optimization of the white light emission and the extraction of internal light modes) in comparison to the bottom-emitting devices. The investigated concepts are beneficial for OLEDs in general, since the replacement of the brittle ITO electrodes and the fabrication of roll-to-roll processing compatible light extraction structures are also desirable for bottom-emitting, or transparent OLEDs.
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Christogiannis, Nikolaos. "Organic microcavities and OLEDs." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/16009/.
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The merging fields of photonics and organic electronics into organic optoelectronics has created a surge of enthusiasm over the possibility of developing low-cost and large-area advanced optoelectronic systems. These applications can combine the best functionalities of both fields, such as tailoring the organic semiconductors by chemical means, engineering the structure in which organic materials are embedded in, are to name a few. These advances have stimulated the excitement over the next generation of optoelectronic systems with enhanced capabilities and low-cost manufacturing processes compared to their inorganic counterparts. Such technology direction is mainly reflected by the high investments towards the aim of developing flexible, and roll-to-roll organic light-emitting diodes and organic solar cells. Interestingly, more sophisticated applications require a deeper understanding of the underlying mechanisms at play that merge concepts from the fields of photonics and organic electronics. Particularly, organic light-emitting diodes (OLEDs) under certain constraints (such as cavity light confinement, strong exciton-photon interaction) exhibit modified spectral emission compared to OLED devices that are not bounded by the same conditions. The introduction of the polariton concept as a quasi-particle, which is part-light and part-matter, has emerged to describe such new physical phenomena caused by this photon-exciton intricate interaction. Polariton physics is well established in inorganic semiconductors were a plethora of physical phenomena have been demonstrated, such as the appearance of Bose-Einstein Condensation or low-threshold laser devices. The later is what has as yet to be demonstrated from the field of solid state physics utilising organic semiconductors. This thesis is focused on the study of the physics and the engineering of organic light-emitting diodes that will aid in the realization of efficient organic polariton LEDs. The main body of work examines various organic semiconductor materials in their ability to reach the strong light and matter interaction regime and, subsequently, to be used in OLEDs as the emissive component. Furthermore, a degradation investigation highlights the issues that affect small-molecule based OLEDs, and finally, the possible pathways for achieving efficient polariton OLEDs are discussed.
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Kasemann, Daniel. "OLEDs under High Current Densities." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-84463.
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This work focuses on a better understanding of the behavior of organic light emitting devices (OLEDs) under intense electrical excitation. Attaining high exciton densities in organic semiconductors by electrical excitation is of special interest for the field of organic semiconductor lasers (OSLs). In these devices, the high singlet exciton density needed in the active layer to obtain population inversion is easily created by pulsed optical pumping, but direct electrical pumping has not been achieved yet. First, the steps necessary to achieve stable high current densities in organic semiconductors are discussed. After determining the optimal excitation scheme using single p-doped transport layers, the device complexity is increased up to full p-i-n OLEDs with their power dependent emission spectra. For this purpose, two exemplary emitter systems are chosen: the fluorescent laser dye 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) doped into Aluminum(III)bis (2-methyl-8-quinolinato)-4-phenylphenolate (Alq3) and the efficient phosphorescent emitter system N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine (alpha-NPD) doped by Iridium(III) bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate) (Ir(MDQ)2(acac)). For pulsed excitation using 50 ns pulses and a repetition rate of 1 kHz, single 100 nm thin p- and n-doped transport layers sustain current densities of over 6 kA/cm2. While the maximum current density decreases with increasing device thickness, the full OLEDs still sustain current densities beyond 800 A/cm2 and exhibit a continuously increasing emission intensity with increasing input power. Next, the time-resolved emission behavior of the singlet and triplet emitter device at high excitation densities is analyzed on the nanosecond scale. Here, the peak emission intensity of the phosphorescent emitter system is found to be more than eight times lower than for the singlet emitter system at comparable current densities. The triplet emitter system exhibits a slow rise of the EL after turn-on which prevents the usage of shorter pulses to enable higher current densities. The singlet emitter system, in contrast, exhibits a fast turn-on and reaches the maximum emission intensity within less than 20 ns. By several additional experiments including streak camera measurements and pump-probe experiments, the strong EL overshoot observed in the first few ns is successfully attributed to a reduced emission intensity in the steady state due to singlet-triplet annihilation. Hence, the separation of singlet emission and singlet-triplet quenching in time domain is demonstrated. At 550 A/cm2 and 10 ns pulse rise time, a peak luminance of 1.5E6 cd/m2 is recorded. Finally, the experimental results are validated by modeling the singlet and triplet population dynamics in the emission layer of the fluorescent system to explain the time-resolved emission characteristics. Using a set of rate equations for the polaron density and the singlet and triplet exciton densities, the overshoot in singlet exciton density at the device turn-on is attributed to the separation of singlet emission and triplet quenching in time domain. Furthermore, by fitting the experimental data, the triplet-triplet annihilation rate in the host guest system is shown to become exciton density dependent at sufficiently high excitation densityDer Schwerpunkt dieser Arbeit liegt auf dem besseren Verständnis des Verhaltens von organischen Leuchtdioden (OLEDs) bei intensiver elektrischer Anregung. Das Erreichen hoher Exzitonendichten in organischen Halbleitern ist insbesondere für organische Halbleiterlaser (organic semiconductor lasers, OSLs) von Interesse. Hierbei werden die für die Inversion benötigten hohen Singulett Exzitonendichten zwar leicht mittels gepulstem optischen Anregen (Pumpen) erreicht, jedoch konnte eine elektrische Anregung bisher noch nicht realisiert werden. Der erste Abschnitt befasst sich mit dem Erreichen von hohen Stromdichten und den dazu nötigen Schritten. Nach dem Ermitteln des optimalen Anregungsschemas an p-dotierten Einzelschichten wird die Komplexität des Systems Schritt für Schritt bis zur kompletten p-i-n OLED erhöht. Hierfür wurden exemplarisch zwei verschiedene Emittersysteme ausgewählt: Aluminum(III)bis (2-methyl-8-quinolinato)-4-phenylphenolate (Alq3) dotiert mit dem fluoreszenten Laserfarbstoff 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) und der effiziente phosphoreszente Emitter Iridium(III)bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate) (Ir(MDQ)2(acac)) in einer N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine (alpha-NPD) Matrix.Bei gepulster Anregung mit einer Pulsweite von 50 ns und einer Wiederholungsrate von 1 kHz sind in 100 nm dünnen p- und n-dotierten Transportschichten Stromdichten von mehr als 6 kA/cm2 möglich. Der Maximalstrom sinkt mit zunehmender Gesamtschichtdicke ab. Die kompletten p-i-n OLEDs ermöglichen eine Stromdichte von über 800 kA/cm2 und weisen eine kontinuierlich mit der Stromdichte steigende Emissionsintensität auf. Anschließend wird die zeitlich aufgelöste Elektrolumineszenz der Singulett- und Triplett-Emitter OLEDs mit Nanosekunden-Auflösung untersucht. Die phosphoreszente OLED weist hierbei, im Vergleich zur fluoreszenten OLED bei vergleichbarer Stromdichte, eine mehr als achtmal geringere Emissionsintensität auf. Des Weiteren steigt die Emissionsintensität nur langsam an, die maximale Intensität wird erst nach 120 ns erreicht. Dies steht im Widerspruch zum Erreichen höherer Stromdichten mittels kürzerer Pulse. Die fluoreszente OLED hingegen zeigt ein schnelles Ansteigen der Emissionsintensität, die maximale Intensität wird nach weniger als 20 ns erreicht. Anhand von zusätzlichen Untersuchungen kann das beobachtete starke Überschießen der Elektrolumineszenz innerhalb der ersten Nanosekunden einer durch Singulett-Triplett Annihilation reduzierten Emission im Gleichgewichtszustand zugeordnet werden. Diese Experimente dokumentieren somit die zeitliche Trennung von Fluoreszenz und Singulett-Triplett Annihilation. Bei einer Stromdichte von 550 A/cm2 und 10 ns Flankenanstiegszeit wird eine maximale Lumineszenz von 1.5E6 cd/m2 gemessen. Der letzte Abschnitt befasst sich mit der Bestätigung der experimentellen Ergebnisse durch die Simulation der Dynamik von Singulett- und Triplett-Exzitonendichte in der Emissionsschicht. Mit Hilfe eines Satzes von gekoppelten Differenzialgleichungen für die Dichte der Polaronen, Singulett Exzitonen und Triplett Exzitonen lässt sich das Überschießen der Elektrolumineszenz der fluoreszenten OLED eindeutig der zeitlichen Trennung von Singulett Emission und Singulett-Triplett Annihilation zuordnen. Außerdem kann durch das Fitten der experimentellen Daten dargestellt werden, dass die Triplett-Triplett Annihilationsrate in dem untersuchten fluoreszenten Emittersystem bei ausreichend hohen Anregungsdichten eine starke Abhängigkeit von der Dichte der Triplett Exzitonen aufweist
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Freitag, Patricia. "White Top-Emitting OLEDs on Metal Substrates." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-70756.
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This work focusses on the development of top-emitting white organic light-emitting diodes (OLEDs), which can be fabricated on metal substrates. Bottom-emitting OLEDs have been studied intensively over the years and show promising perspectives for future commercial applications in general lighting. The development of top-emitting devices has fallen behind despite the opportunities to produce these devices also on low-cost opaque substrates. This is due to the challenges of top-light-emission concerning the achievement of a broad and well-balanced white emission spectrum in presence of a strong microcavity. The following work is a further step towards the detailed understanding and optimization of white top-emitting OLEDs. First, the available metal substrates and the deposited silver electrodes are examined microscopically to determine their surface characteristics and morphology in order to assess their applicability for thin-film organic stacks of OLEDs. The examination shows the suitability for untreated Alanod metal substrates, which display low surface roughness and almost no surface defects. For the deposited silver anodes, investigations via AFM show a strong influence of the deposition rate on the surface roughness. In the main part of the work top-emissive devices with both hybrid and all-phosphorescent architecture are investigated, in which three or four emitter materials are utilized to achieve maximum performance. The feasibility for top-emitting white OLEDs in first and second order devices is investigated via optical simulations, using the example of a three-color hybrid OLED. Here, the concept of a dielectric capping layer on top of the cathode is an essential criterion for broadband and nearly angle independent light emission. The main focus concerning the investigation of fabricated devices is the optimization of the organic stacks to achieve high efficiencies as well as excellent color quality of warm white emission. The optimization of the hybrid layer structure based on three emitter materials using a combined aluminum-silver anode mirror resulted in luminous efficacies up to 13.3 lm/W and 5.3 % external quantum efficiency. Optical analysis by means of simulation revealed a superior position concerning internal quantum efficiency compared to bottom-emitting devices with similar layer structure. The devices show an enhanced emission in forward direction compared to an ideal Lambertian emitter, which is highly preferred for lighting applications. The color quality - especially for devices based on a pure Al anode - is showing excellent color coordinates near the Planckian locus and color rending indices up to 77. The introduction of an additional yellow emitter material improves the luminous efficacy up to values of 16.1 lm/W and external quantum efficiencies of 5.9 %. With the choice of a all-phosphorescent approach, using orange-red, light blue and green emitter materials, luminous efficacies of 21.7 lm/W are realized with external quantum efficiencies of 8.5 %. Thereby, color coordinates of (x, y) = (0.41, 0.45) are achieved. Moreover, the application of different crystalline capping layers and alternative cathode materials aim at a scattering of light that further reduces the angular dependence of emission. Experiments with the crystallizing material BPhen and thin carbon nanotube films (CNT) are performed. Heated BPhen capping layer with a thickness of 250 nm show a lower color shift compared to the NPB reference capping layer. Using CNT films as cathode leads to a broadband white emission at a cavity thickness of 160 nm. However, due to very high driving voltages needed, the device shows low luminous efficacy. Finally, white top-emitting organic LEDs are successfully processed on metal substrates. A comparison of three and four color based hybrid devices reveal similar performance for the devices on glass and metal substrate. Only the devices on metal substrate show slightly higher leakaged currents. During repeated mechanical bending experiments with white devices deposited on 0.3 mm thin flexible Alanod substrates, bending radii up to 1.0 cm can be realized without device failureDiese Arbeit richtet ihren Schwerpunkt auf die Entwicklung von top-emittierenden weißen organischen Leuchtdioden (OLEDs), welche auch auf Metallsubstraten gefertigt werden können. Im Laufe der letzten Jahre wurden bottom-emittierende OLEDs sehr intensiv studiert, da sie vielversprechende Perspektiven für zukünftige kommerzielle Anwendungen in der Allgemeinbeleuchtung bieten. Trotz der Möglichkeit, OLEDs auch auf kostengünstigen lichtundurchlässigen Substraten fertigen zu können, blieb die Entwicklung von top-emittierenden Bauteilen dabei allerdings zurück. Dies läßt sich auf die enormen Herausforderungen von top-emittierenden OLEDs zurückführen, ein breites und ausgeglichenes weißes Abstrahlungsspektrum in Gegenwart einer Mikrokavität zu generieren. Die folgende Arbeit liefert einen Beitrag zum detaillierten Verständnis und der Optimierung von weißen top-emittierenden OLEDs. Zunächst werden die verfügbaren Metallsubstrate und abgeschiedenen Silberelektroden auf ihre Oberflächeneigenschaften und Morphologie mikroskopisch untersucht, um damit ihre Verwendbarkeit für organische Dünnfilmstrukturen in OLEDs einzuschätzen. Die Untersuchung zeigt eine Eignung von unbehandelten Alanod Metallsubstraten auf, welche eine niedrige Oberflächenrauigkeit und fast keine Oberflächendefekte besitzen. Bei den abgeschiedenen Silberelektroden zeigen Untersuchungen mit dem Rasterkraftmikroskop eine starke Beeinflussung der Oberflächenrauigkeit durch die Aufdampfrate. Im Hauptteil der Arbeit werden top-emittierende Dioden mit hybrid und voll-phosphoreszenter Architektur untersucht, in welcher drei oder vier Emittermaterialien verwendet werden, um eine optimale Leistungscharakteristik zu erreichen. Die Realisierbarkeit von top-emittierenden weißen OLEDs in Dioden erster und zweiter Ordnung wird durch optische Simulation am Beispiel einer dreifarb-OLED mit Hybridstruktur ermittelt. Dabei ist das Konzept der dielektrischen Deckschicht - aufgebracht auf die Kathode - ein essenzielles Kriterium für breitbandige und annähernd winkelunabhängige Lichtemission. Der Schwerpunkt im Hinblick auf die Untersuchung von hergestellten Dioden liegt in der Optimierung der organischen Schichtstrukturen, um hohe Effizienzen sowie exzellente warmweiße Farbqualität zu erreichen. Im Rahmen der Optimierung von hybriden Schichtstrukturen basierend auf drei Emittermaterialien resultiert die Verwendung eines kombinierten Aluminium-Silber Anodenspiegels in einer Lichtausbeute von 13.3 lm/W und einer externen Quanteneffizienz von 5.3 %.Eine optische Analyse mit Hilfe von Simulationen zeigt eine überlegene Stellung hinsichtlich der internen Quanteneffizient verglichen mit bottom-emittierenden Dioden ähnlicher Schichtstruktur. Die Dioden zeigen eine verstärkte vorwärts gerichtete Emission im Vergleich zu einem idealen Lambertschen Emitter, welche in hohem Maße für Beleuchtungsanwendungen erwünscht ist. Es kann eine ausgezeichnete Farbqualität erreicht werden - insbesondere für Dioden basierend auf einer reinen Aluminiumanode - mit Farbkoordinaten nahe der Planckschen Strahlungskurve und Farbwiedergabeindizes bis zu 77. Die weitere Einführung eines zusätzlichen gelben Emittermaterials verbessert die Lichtausbeute auf Werte von 16.1 lm/W und die externe Quanteneffizient auf 5.9 %. Mit der Wahl eines voll-phosphoreszenten Ansatzes unter der Verwendung eines orange-roten, hellblauen und grünen Emittermaterials werden Lichtausbeuten von 21.7 lm/W und externe Quanteneffizienten von 8.5 % erzielt. Damit werden Farbkoordinaten von (x, y) = (0.41, 0.45) erreicht. Darüberhinaus zielt die Verwendung von verschiedenen kristallinen Deckschichten und alternativen Kathodenmaterialien auf eine Streuung des ausgekoppelten Lichts ab, was die Winkelabhängigkeit der Emission vermindern soll. Experimente mit dem kristallisierenden Material BPhen und dünnen Filmen aus Kohlenstoffnanoröhren werden dabei durchgeführt. Geheizte BPhen Deckschichten mit einer Schichtdicke von 250 nm zeigen eine geringere Farbverschiebung verglichen mit einer NPB Referenzdeckschicht. Die Verwendung von Kohlenstoffnanoröhren als Kathode führt zu einer breitbandigen weißen Emission bei einer Kavitätsschichtdicke von 160 nm. Schließlich werden weiße top-emittierende organische Leuchtdioden erfolgreich auf Metallsubstraten prozessiert. Ein Vergleich von drei- und vierfarb-basierten hybriden Bauteilen zeigt ähnliche Leistungsmerkmale für Dioden auf Glas- und Metallsubstraten. Während wiederholten mechanischen Biegeexperimenten mit weißen Dioden auf 0.3 mm dicken flexiblen Alanodsubstraten können Biegeradien bis zu 1.0 cm ohne Bauteilausfall realisiert werden
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Yu, Xiaoming. "Organic light emitting diodes (OLEDs) for lighting /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20YU.
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Scheffel, Marcus. "Charakterisierung und Optimierung der Emissionseigenschaften organischer Leuchtdioden (OLEDs) /." Aachen : Shaker, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=012949633&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Zuniga, Carlos A. "Solution-processable charge transport layers for phosphorescent OLEDs." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/43671.
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The development of new charge transport materials for use in phosphorescent organic light-emitting diodes (OLEDs) remains an important area of research. In this thesis, several examples of carbazole-containing norbornene-based side-chain polymers were synthesized and studied. In addition, several examples of ambipolar transport moieties were produced by combining hole- (carbazole) and electron- (oxadiazole or triazole) transport groups and examined as both small molecules and as norbornene-based side-chain polymers. UV-visible absorption, fluorescence spectroscopy, cyclic voltammetry, and other methods were used to evaluate the properties of the charge transport materials for use as hole- and/or host layers. It was found that side-functionalization produced polymers with photophysical and electrochemical properties corresponding to the charge transport side groups attached. In addition, several crosslinkable hole-transporting materials (copolymer or small molecule-based) incorporating either benzocyclobutenes, trifluorovinyl ethers, oxetanes, or bis(styrene)s were developed. Thin-films of the crosslinkable materials were shown to be readily insolubilized by thermal treatment permitting the deposition of a subsequent layer from solution onto the crosslinked layer. OLEDs fabricated using several of these materials produced efficient devices. Overall, it was shown that side-chain functionalization can be used to afford solution-processable charge transport polymers where the properties are determined mainly by the side group attached. As such, this approach could be extended to additional examples of charge transport moieties.
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Dinis, João Gonçalo Côrte-Real. "Desenvolvimento e caracterização de OLEDs para fins decorativos." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/11727.
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Mestrado em Engenharia FísicaEste trabalho foca essencialmente o fabrico e completa caracterização de OLEDs para fins de iluminação decorativa. Os dispositivos foram fabricados por evaporação térmica usando small molecules. Foram obtidos resultados que mostram a viabilidade das soluções de estrutura que foram usadas, nomeadamente o brilho, a pureza de cor e as relativamente boas curvas de corrente-tensão que mostram igualmente a possível viabilidade em termos comerciais. Como conclusão final, este trabalho mostra que efetivamente é possível com soluções de estruturas simples fabricar e desenvolver OLEDs para os fins acima descritos.
This work focuses essentially on the conception and complete characterization of OLEDs for luminous decoration purposes. The devices were produced by thermal evaporation of small molecules. The results obtained demonstrate that the viability of the used structures, mainly the brightness levels, the colour purity and the reasonably acceptable current-voltage behaviour show that these devices are equally viable to extend to commercial production. As a final conclusion, this work shows that effectively it is possible with simple structure solutions to produce and develop OLEDs for the purposes described above.
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Sykora, Benedikt Reinhold. "Influence of emitter orientation in perylene based OLEDs." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/11828.
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Mestrado em Ciência e Engenharia de MateriaisOs díodos orgânicos emissores de luz (organic light-emitting diodes ou OLEDs) têm como elemento funcional um filme fino de um semicondutor orgânico para a criação de excitões (pares electrão-lacuna), que emitem luz quando relaxam. O objetivo desta dissertação de mestrado é investigar o efeito da orientação dipolar de filmes baseados em perilenos de tetraphenyldibenzoperiflanthene (DBP) e diindenoperylene ( DIP), e das mesmas moléculas dispersas numa ma matriz de 5,6,11,12- tetraphenylnaphthacene (rubreno). O estudo tenta identificar uma possível relação entre o comportamento destes filmes e a eficiência do respetivo OLED. Observa-se que os filmes de DBP são amorfos, apresentam uma superfície lisa e absorvem mais luz do que os filmes de DIP, que se caracterizam por uma estrutura cristalina e uma superfície irregular. Os resultados combinados de simulações e de medições de fotoluminescência com dependência angular revelam que as moléculas de DBP apresentam orientação horizontal, estando as moléculas de DIP orientadas verticalmente. Este facto pode explicar o acoplamento mais forte das moléculas de DIP aos plasmões de superfície, em comparação com o DBP. As características gerais dos filmes de DBP ou DIP mantêm-se mesmo quando estes são depositados nos substratos de N, N '-di(1-naftil-N,N-difenil-(1,1'- bifenil)-4,4' –diamina utilizados ma preparação dos OLEDs, o que permite a comparação direta entre as duas configurações. Os resultados obtidos com os OLEDs baseados em filmes puros de DBP ou DIP apresentam valores de eficiência quântica externa (EQE) da ordem de 0,2 e 0,04 %, respetivamente. Estes valores baixos podem explicar-se pela orientação vertical dos dipolos do DIP, conduzindo a um fator de emissão de 27% (light outcoupling), claramente superior ao obtido com o OLED baseado no DBP (16%). Estas diferenças acentuam-se quando na comparação destes filmes com o comportamento dos filmes rubreno equivalentes dopados com 1% de DBP e DIP. Se por um lado não se observa nenhuma orientação dipolar preferencial no caso do DIP, as moléculas de DBP na matriz de rubreno estão quase na sua totalidade orientadas horizontalmente, o que aumenta o factor de emissão. A forte orientação preferencial no caso do DBP pode igualmente justificar o aumento de EQE de 0,2 % e 0,04% nos OLEDs com os filmes puros de DBP e DIP, para 3% e 0,5% no caso dos OLEDs com os filmes dopados. O aumento da eficiência pode também dever-se ao aumento da transferência energética da matriz de rubreno para os centros emissores. O forte efeito da orientação horizontal do emissor na eficiência dos OLEDs manifesta-se igualmente no notável aumento do factor de emissão de luz observado entre os filmes de DBP (fortemente orientados) e DIP (pouco orientados), que é de cerca de 70% no caso das camadas de emissão baseadas nos filmes puros, e de 44 % no caso dos filmes dopados.
Organic light-emitting diodes (OLEDs) contain thin films of organic semiconductors to create excitons (electron-hole-pairs), which will emit light if they de-excite. The aim of this master thesis is to investigate a possible link between the dipole orientation of perylene based films of tetraphenyldibenzoperiflanthene (DBP) and diindenoperylene (DIP), and of the same molecules dispersed in a 5,6,11,12-tetraphenylnaphthacene matrix. The study also compares the behavior of these films with that of the corresponding OLEDs. It is shown that DBP neat films are essentially amorphous, with a rather smooth surface and they absorb more light than the DIP films, which are crystalline and have a rough surface. Simulation results and angle-dependent p-polarised photoluminescence measurements reveal that the DBP molecules have a horizontal orientation, while the DIP molecules are vertically oriented. This explains the stronger coupling of DIP molecules to the surface plasmons, when compared to the DBP molecules. The general characteristics of the DBP or DIP films do not change when these are deposited onto N,N’-di(1-naphtyl-N,N’-diphenyl-(1,1’-biphenyl)-4,4’diamine hole transport layers used as substrates in OLEDs, thus allowing a direct comparison between both configurations. The OLEDs comprising neat films of DBP or DIP have small external quantum efficiency (EQE) values of 0.2 and 0.04%, respectively. This is probably due to the strong vertical molecular orientation of the DBP, leading to a high lightoutcoupling factor of 27%, when compared to 16% of the DIP OLED. These differences are accentuated when comparing the behavior of the neat films with equivalent rubrene films doped with 1% of DBP or DIP. While the DIP exhibits a rather isotropic orientation, the DBP molecules are fully horizontal within the doped film, thus improving the light-outcoupling. This may partly justify the increase of EQE from 0.2% and 0.04% of the neat film OLEDs to 3% and 0.5% for the doped DBP and DIP OLEDs, respectively. The improvement of the efficiency may also be due to the enhancement of the energy transfer from the rubrene matrix to the emitter dyes. The horizontal orientation of the emitter has a huge effect on the efficiency of perylene-based OLEDs, apparent also on the remarkable increase of the lightoutcoupling of strongly oriented DBP dipoles in comparison to the weakly oriented DIP, which is of the order of 70% in the case of the neat emission layers, and of 44% in the case of the doped counterparts.
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Oliveira, Daniel Filipe Martins de. "OLEDs on stainless steel: implementation and degradation studies." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/9541.
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Mestrado em Engenharia FísicO objetivo deste trabalho consistiu em contribuir para o desenvolvimento de um novo dispositivo, com fins decorativos, baseado num Díodo Emissor de Luz Orgânico (em inglês: OLED) construído sobre um ladrilho de (aço) inox. Este estudo enquadra-se num projecto SI I&DT (Sistema de Incentivos a Investigação e Desenvolvimento Tecnológico) Individual com uma empresa portuguesa da area dos ladrilhos metálicos. O inox possui características ópticas particulares que deveriam ser mantidas após a construção do OLED. Um dos principais problemas consiste na transparência ótica, na gama do visível, das várias camadas que constituem o dispositivo. Neste trabalho foram abordados essencialmente dois problemas: o isolamento elétrico da superfície de inox e a eficácia de uma barreira flexível que deverá proteger o OLED da exposição ambiental. Deste modo, a primeira parte deste trabalho focou-se na avaliação da possibilidade de crescimento de uma camada isolante no ladrilho de inox, espessa o suficiente para aplanar a sua rugosidade mas sem comprometer severamente a sua identidade característica. A ultima camada de um OLED e uma barreira protetora que tem como objetivo evitar a exposição ambiental que afecta o tempo de vida do dispositivo. Para esse fim, testou-se uma barreira comercial flexível. Por conseguinte, a segunda parte deste trabalho focou-se no estudo da degradação de um OLED, comparando para isso OLEDs não encapsulados com encapsulados - com vidro (uma barreira de referência) ou com a nova barreira flexível. A comparação baseou-se na evolução temporal do consumo de corrente eléctrica e da electroluminescência do dispositivo. Adicionalmente, utilizaram-se imagens de microscópio para compreender melhor a evolução da degradação. Os resultados sugerem que a degradação dos dispositivos é governada por diferentes processos, quer nos encapsulados ou não encapsulados. No entanto, a barreira encapsulante utilizada permitiu alterar (ou eliminar) os tempos de ativação de alguns desses processos. Estes processos de degradação foram estudados e analisados de forma a permitir uma compreensão mais clara da progressão da degradação que afeta o tempo de vida do OLED tão severamente.
The goal of this work was to contribute to the development of a new device, for decorative purposes, based on an Organic Light-Emitting Diode (OLED) built on top of a stainless steel (StS) tile. The framework of these studies was a SI I&DT (Sistema de Incentivos a Investiga c~ao e Desenvolvimento Tecnol ogico) Individual Project with a Portuguese company in the area of metallic tiles. StS possesses particular optical characteristics that were supposed to be maintained after the OLED was built. One of the major problems is the optical transparency, in the visible range, of the several layers that constitute the device. In this work two particular issues have been addressed: the electric insulation of the StS surface and the e ectiveness of a exible barrier to protect the OLED from environmental exposure. Therefore, the rst part of this work focused on evaluating if an insulating layer could be grown on a StS tile, thick enough to smooth its roughness but without compromising its characteristic identity too severely. The last layer in an OLED is a protective barrier which aims to avoid ambient exposure that a ects the life time of the device. In order to accomplish that, a very thin exible commercial barrier was tested. Hence the second part of this work focused on studying the OLED degradation by comparing notencapsulated OLEDs with encapsulated ones - either by glass (a reference barrier) or the new exible barrier. The comparison was based on the time evolution of the electric current consumption and the electro-luminescence of the device. Plus, microscopy images were used to better understand the evolution of the degradation. Results suggest that di erent processes rule the degradation of the devices, either encapsulated or not. However, the encapsulation barrier used was able to change (or eliminate) the activation timings of some processes. These degradation processes were studied and analysed in order to accomplish a clear understanding of the degradation's progression that severely a ects OLED life time.
Books on the topic "OLEDs"
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Koden, Mitsuhiro. Flexible OLEDs. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2.
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Yersin, Hartmut, ed. Highly Efficient OLEDs. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2018. http://dx.doi.org/10.1002/9783527691722.
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Buckley, Alastair. Organic light-emitting diodes (OLEDs): Materials, devices and applications. Oxford: Woodhead Publishing, 2013.
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International Display Research Conference (20th 2000 Palm Beach, Fla.). Conference record of the 20th International Display Research Conference: September 25-28, 2000, Palm Beach, Florida, USA : featuring invited symposia on microdisplays, technologies for electronic paper, OLEDs, and substrates and electronics for flexible displays. San Jose, CA: Society for Information Display, 2000.
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Aub, Max. Cuentos mexicanos (con pilo n). Me xico, D.F: Consejo Nacional para la Cultura y las Artes, Direccio n General de Publicaciones, 1990.
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North, Raynette. So great a cloud of witnesses ...: A history of St. John's Anglican Church, Olds, Alberta, 1894-1994. [S.l: s.n., 1994.
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Tsujimura, Takatoshi. OLED Displays. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118173053.
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Templier, François, ed. OLED Microdisplays. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781119004745.
Full textBook chapters on the topic "OLEDs"
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Koden, Mitsuhiro. "Encapsulating Technologies." In Flexible OLEDs, 71–79. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_6.
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Koden, Mitsuhiro. "OLEDs with On-Demand Patterns by Ink-Jet Printing." In Flexible OLEDs, 97–104. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_8.
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Koden, Mitsuhiro. "Flexible Substrates." In Flexible OLEDs, 35–51. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_4.
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Koden, Mitsuhiro. "History of Flexible OLEDs." In Flexible OLEDs, 19–33. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_3.
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Koden, Mitsuhiro. "Fundamentals of Flexible OLEDs." In Flexible OLEDs, 5–18. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_2.
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Koden, Mitsuhiro. "Introduction." In Flexible OLEDs, 1–4. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_1.
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Koden, Mitsuhiro. "Novel Electrode Technologies." In Flexible OLEDs, 81–95. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_7.
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Koden, Mitsuhiro. "Gas Barrier Technologies." In Flexible OLEDs, 53–69. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3544-2_5.
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Yersin, Hartmut, Rafał Czerwieniec, Marsel Z. Shafikov, and Alfiya F. Suleymanova. "TADF Material Design: Photophysical Background and Case Studies Focusing on Cu(I) and Ag(I) Complexesa." In Highly Efficient OLEDs, 1–60. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2018. http://dx.doi.org/10.1002/9783527691722.ch1.
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Kim, Hwang-Beom, Dongwook Kim, and Jang-Joo Kim. "Exciplex: Its Nature and Application to OLEDs." In Highly Efficient OLEDs, 331–76. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2018. http://dx.doi.org/10.1002/9783527691722.ch10.
Full textConference papers on the topic "OLEDs"
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Chao, Paul C. P., Yen-Ping Hsu, Yung-Hua Kao, and Kuei-Yu Lee. "A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays." In ASME 2014 Conference on Information Storage and Processing Systems. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/isps2014-6964.
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Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.
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Aziz, Hany. "OLEDs." In Organic Photonics and Electronics. Washington, D.C.: OSA, 2006. http://dx.doi.org/10.1364/ope.2006.opma4.
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Furong Zhu, Ong Kian Soo, Tan Li Wei, Hao Xiaotao, and Liew Pooi Kwan. "High-contrast OLEDs." In 2005 IEEE LEOS Annual Meeting. IEEE, 2005. http://dx.doi.org/10.1109/leos.2005.1548142.
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Jacobs, Joep, Dirk Hente, and Eberhard Waffenschmidt. "Drivers for OLEDs." In 2007 IEEE Industry Applications Annual Meeting. IEEE, 2007. http://dx.doi.org/10.1109/07ias.2007.180.
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Burrow, Paul. "UV-Emitting OLEDs." In Frontiers in Optics. Washington, D.C.: OSA, 2005. http://dx.doi.org/10.1364/fio.2005.stub2.
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Jacobs, Joep, Dirk Hente, and Eberhard Waffenschmidt. "Drivers for OLEDs." In 2007 IEEE Industry Applications Annual Meeting. IEEE, 2007. http://dx.doi.org/10.1109/ias.2007.180.
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Boerner, Herbert. "OLEDs for lighting." In Photonics Europe, edited by Paul L. Heremans, Michele Muccini, and Eric A. Meulenkamp. SPIE, 2006. http://dx.doi.org/10.1117/12.667217.
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Callens, M. K., D. Yokoyama, and K. Neyts. "Anisotropy in OLEDs." In SPIE Organic Photonics + Electronics, edited by Franky So, Chihaya Adachi, and Jang-Joo Kim. SPIE, 2015. http://dx.doi.org/10.1117/12.2189031.
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Visser, Robert Jan. "Encapsulation of OLEDs." In Organic Photonics and Electronics. Washington, D.C.: OSA, 2006. http://dx.doi.org/10.1364/ope.2006.optua1.
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Kreye, D., M. Toerker, U. Vogel, and J. Amelung. "Full colour RGB OLEDs on CMOS for active-matrix OLED microdisplays." In SPIE Optics + Photonics, edited by Zakya H. Kafafi and Franky So. SPIE, 2006. http://dx.doi.org/10.1117/12.680758.
Full textReports on the topic "OLEDs"
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Anil Duggal, Don Foust, Chris Heller, Bill Nealon, Larry Turner, Joe Shiang, Nick Baynes, Tim Butler, and Nalin Patel. OLEDS FOR GENERAL LIGHTING. Office of Scientific and Technical Information (OSTI), February 2004. http://dx.doi.org/10.2172/836831.
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Hippola, Chamika. OLEDs on Flexible Substrates. Ames (Iowa): Iowa State University, January 2018. http://dx.doi.org/10.31274/cc-20240624-1076.
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Cai, Yuankun. Organic light emitting diodes (OLEDS) and OLED-based structurally integrated optical sensors. Office of Scientific and Technical Information (OSTI), January 2010. http://dx.doi.org/10.2172/985317.
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Joseph Shiang, James Cella, Kelly Chichak, Anil Duggal, Kevin Janora, Chris Heller, Gautam Parthasarathy, Jeffery Youmans, and Joseph Shiang. High Efficiency, Illumination Quality OLEDs for Lighting. Office of Scientific and Technical Information (OSTI), March 2008. http://dx.doi.org/10.2172/951274.
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