Organic Light Emitting Devices

Organic Light Emitting Devices

Recent developments, however, make it possible to manufacture organic light-emitting devices that are thin, bright, efficient, and stable and that produce a broad range of colors. This book surveys the current status of the field.

Author: Joseph Shinar

Publisher: Springer Science & Business Media

ISBN: 9780387217208

Category: Technology & Engineering

Page: 309

View: 391

Although it has long been possible to make organic materials emit light, it has only recently become possible to do so at the level and with the efficiency and control necessary to make the materials a useful basis for illumination in any but the most specialized uses. This book surveys the current status of the field.
Categories: Technology & Engineering

Organic Light Emitting Devices

Organic Light Emitting Devices

This book reflects a decade of intense research on organic light emitting devices (OLEDs), culminating in excellent successes over the last few years which have resulted in the first commercializations of organic displays.

Author: Klaus Müllen

Publisher: John Wiley & Sons

ISBN: 9783527607235

Category: Science

Page: 426

View: 734

This high-class book reflects a decade of intense research, culminating in excellent successes over the last few years. The contributions from both academia as well as the industry leaders combine the fundamentals and latest research results with application know-how and examples of functioning displays. As a result, all the four important aspects of OLEDs are covered: - syntheses of the organic materials - physical theory of electroluminescence and device efficiency - device conception and construction - characterization of both materials and devices. The whole is naturally rounded off with a look at what the future holds in store. The editor, Klaus Muellen, is director of the highly prestigious MPI for polymer research in Mainz, Germany, while the authors include Nobel Laureate Alan Heeger, one of the most notable founders of the field, Richard Friend, as well as Ching Tang, Eastman Kodak's number-one OLED researcher, known throughout the entire community for his key publications.
Categories: Science

Device Architecture and Materials for Organic Light Emitting Devices

Device Architecture and Materials for Organic Light Emitting Devices

Device Architecture and Materials for Organic Light-Emitting Devices focuses on the design of new device and material concepts for organic light-emitting devices, thereby targeting high current densities and an improved control of the ...

Author: Sarah Schols

Publisher: Springer Science & Business Media

ISBN: 9400716087

Category: Science

Page: 154

View: 296

Device Architecture and Materials for Organic Light-Emitting Devices focuses on the design of new device and material concepts for organic light-emitting devices, thereby targeting high current densities and an improved control of the triplet concentration. A new light-emitting device architecture, the OLED with field-effect electron transport, is demonstrated. This device is a hybrid between a diode and a field-effect transistor. Compared to conventional OLEDs, the metallic cathode is displaced by one to several micrometers from the light-emitting zone, reducing optical absorption losses. The electrons injected by the cathode accumulate at an organic heterojunction and are transported to the light-emission zone by field-effect. High mobilities for charge carriers are achieved in this way, enabling a high current density and a reduced number of charge carriers in the device. Pulsed excitation experiments show that pulses down to 1 μs can be applied to this structure without affecting the light intensity, suggesting that pulsed excitation might be useful to reduce the accumulation of triplets in the device. The combination of all these properties makes the OLED with field-effect electron transport particularly interesting for waveguide devices and future electrically pumped lasers. In addition, triplet-emitter doped organic materials, as well as the use of triplet scavengers in conjugated polymers are investigated.
Categories: Science

High Efficiency Organic Light Emitting Devices for Lighting

High Efficiency Organic Light Emitting Devices for Lighting

Incorporate internal scattering layers and microlens arrays in high efficiency OLED to achieve up to 70% EQE.

Author:

Publisher:

ISBN: OCLC:1065998666

Category:

Page:

View: 700

Incorporate internal scattering layers and microlens arrays in high efficiency OLED to achieve up to 70% EQE.
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Advances in Organic Light emitting Devices

Advances in Organic Light emitting Devices

Organic electroluminescence (OEL) is the phenomenon of electrically-driven emission of light from organic materials; including both fluorescent and phosphorescent organic solids.

Author: Youngkyoo Kim

Publisher: Trans Tech Publication

ISBN: 0878494839

Category: Technology & Engineering

Page: 140

View: 998

Organic electroluminescence (OEL) is the phenomenon of electrically-driven emission of light from organic materials; including both fluorescent and phosphorescent organic solids. The organic light-emitting device (OLED), which exploits OEL emission from organic semiconducting thin films (with thicknesses of less than a few hundred nanometers), sandwiched between electrodes, has attracted keen interest in its application to flat-panel displays, due to its high luminous efficiency, low driving voltage, tunable colors as well as a convenient device-structure design and low fabrication costs when compared with every other known display device.
Categories: Technology & Engineering

Organic Light Emitting Materials and Devices

Organic Light Emitting Materials and Devices

As researchers continue to develop novel applications for these materials, feasible solutions for large-scale manufacturing are increasingly important. Organic Light-Emitting Materials and Devices covers all aspects o

Author: Zhigang Li

Publisher: CRC Press

ISBN: 9781420017069

Category: Science

Page: 673

View: 538

New advances offer flexible, low-cost fabrication methods for light-emitting materials, particularly in display technologies. As researchers continue to develop novel applications for these materials, feasible solutions for large-scale manufacturing are increasingly important. Organic Light-Emitting Materials and Devices covers all aspects o
Categories: Science

OLED Fundamentals

OLED Fundamentals

A Comprehensive Source for Taking on the Next Stage of OLED R&DOLED Fundamentals: Materials, Devices, and Processing of Organic Light-Emitting Diodes brings together key topics across the field of organic light-emitting diodes (OLEDs), from ...

Author: Daniel J. Gaspar

Publisher: CRC Press

ISBN: 9781466515192

Category: Technology & Engineering

Page: 494

View: 502

A Comprehensive Source for Taking on the Next Stage of OLED R&D OLED Fundamentals: Materials, Devices, and Processing of Organic Light-Emitting Diodes brings together key topics across the field of organic light-emitting diodes (OLEDs), from fundamental chemistry and physics to practical materials science and engineering aspects to design and manufacturing factors. Experts from top academic institutions, industry, and national laboratories provide thorough, up-to-date coverage on the most useful materials, devices, and design and fabrication methods for high-efficiency lighting. The first part of the book covers all the construction materials of OLED devices, from substrate to encapsulation. For the first time in book form, the second part addresses challenges in devices and processing, including architectures and methods for new OLED lighting and display technologies. The book is suitable for a broad audience, including materials scientists, device physicists, synthetic chemists, and electrical engineers. It can also serve as an introduction for graduate students interested in applied aspects of photophysics and electrochemistry in organic thin films.
Categories: Technology & Engineering

A New Generation of Organic Light Emitting Materials and Devices

A New Generation of Organic Light Emitting Materials and Devices

This Research Topic mainly focus on this new generation of organic light-emitting materials and devices, including design, synthesis, and characterization of light-emitting organic molecules with tunable excited states, and their structural ...

Author: Shi-Jian Su

Publisher: Frontiers Media SA

ISBN: 9782889631636

Category:

Page:

View: 653

Since the invention of the first efficient organic light-emitting diodes (OLEDs) by C. T. Tang and S. VanSlyke, OLEDs have attracted close interest as a promising candidate for next-generation full-color displays and future solid-state lighting sources because of a number of advantages like high brightness and contrast, high luminous efficiency, fast response time, wide viewing angle, low power consumption, and light weight. The recombination of holes and electrons under electrical excitation typically generates 25% singlet excitons and 75% triplet excitons. For traditional fluorescent OLEDs, only 25% singlet excitons can be utilized to emit light, while the other 75% triplet excitons are generally wasted through nonradiative transition. By adopting noble metal phosphorescent complexes, an internal quantum efficiency (IQE) of 100% could be achieved by utilizing both the 25% singlet excitons and 75% triplet excitons. However, these phosphors usually contain nonrenewable and highcost iridium or platinum noble metals. Most recently, unity IQE has been readily achieved through noble metal-free purely organic emitters, such as thermally activated delayed fluorescence (TADF) emitters, hybridized local and charge-transfer state (HLCT) “hot exciton” emitters, binary- or ternary-mixed donor-acceptor exciplex emitters, and neutral p radical emitters, etc. In addition, the combination of conventional p-type hole-transport and n-type electron-transport materials in an appropriate device structure can also provide an uncommon efficiency. Both strategies are essential and attractive for high-performance and low-cost full-color displays and white OLED applications. This Research Topic mainly focus on this new generation of organic light-emitting materials and devices, including design, synthesis, and characterization of light-emitting organic molecules with tunable excited states, and their structural, electrical, and photophysical properties. Contributions relating to carrier transporting materials and corresponding device engineering are also included. Two mini reviews and thirteen original research articles by recognized academic experts in their respective fields are collected in this Research Topic, which will offer a broad perspective of noble metal-free organic light emitters, including conventional fluorescent emitters, TADF emitters, HLCT emitters, exciplex emitters, aggregation-induced emission (AIE) luminogens, and their corresponding devices. We believe this eBook should attract the attention of multidisciplinary researchers in the fields of materials science, organic synthesis, and electronic device engineering, especially for those engaged in OLED-related areas.
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Ultrahigh Efficiency White Organic Light Emitting Devices

Ultrahigh Efficiency White Organic Light Emitting Devices

These are achievable through well designed device architectures.

Author: Yiru Sun

Publisher: Proquest, UMI Dissertation Publishing

ISBN: 1243569522

Category:

Page: 244

View: 537

Organic light emitting devices (OLEDs) have been intensively studied for more than 20 years, for they offer a broad range of emitting colors, high efficiency, wide viewing angle, and ultra-thin thickness that enable new-generation devices such as transparent and rollable displays and lighting panels. Indeed, efficient electrophosphorescent white OLED (WOLED) has led to commercial flat panel displays whose internal quantum efficiency (IQE) is approaching to 100%, while exhibits superior color balance along with desirable features such as continuous brightness control, high contrast, and no turn-on delay. In the past decade, with the steadily improved external efficiency of WOLED, the application of WOLED to reduce the energy consumption of interior lighting, which now costs more than $230 billion annually, has attracted considerable interest as well, since WOLED has surpassed the efficiency of commonplace fluorescent lamps. This Thesis mainly focuses on the improvement of one of the most important characteristics of WOLED, external quantum efficiency (EQE), which is a product of IQE and the light outcoupling efficiency (etaout). Issues such as proper combination of host and dopant materials, balanced charge recombination in the emission region, efficient utilization of excitons, etc., can lead to improved IQE of WOLED. These are achievable through well designed device architectures. In this Thesis, methods such as utilization of fluorescence filtered phosphorescence, a stepped progression of energy barriers to charges to form multiple exciton generation regions, and vertically stacked iv WOLED connected by non-metal charge generation layers, are presented. On the other hand, etaout for OLEDs fabricated on conventional flat glass substrates is only ∼20%, mainly due to the optical characteristics of the active layers and the substrate of OLED. This leaves considerable opportunity for improvement of EQE. This Thesis presents potentially low-cost methods to outcouple the light originally confined in the substrate, as well as the light originally in the waveguided modes in the organic and anode layers, without changing the emitting spectrum. These methods result in an enhancement factor of (2.3+/-0.2) in the external quantum and power efficiencies. Through these approaches, a better understanding of WOLED operation, and several record efficiencies of WOLEDs have been demonstrated.
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Enhanced Efficiency of Organic Light emitting Devices by Employing a Periodically Corrugated Conductive Photoresist

Enhanced Efficiency of Organic Light emitting Devices by Employing a Periodically Corrugated Conductive Photoresist

Abstract: Photons trapped in the form of waveguide (WG) modes associated with the organic/organic interface and in the form of surface plasmon polariton (SPP) modes associated with the metallic electrode/organic interface result in a large ...

Author:

Publisher:

ISBN: OCLC:1053742033

Category:

Page:

View: 417

Abstract: Photons trapped in the form of waveguide (WG) modes associated with the organic/organic interface and in the form of surface plasmon polariton (SPP) modes associated with the metallic electrode/organic interface result in a large energy loss in organic light-emitting devices (OLEDs). We demonstrate the efficient outcoupling of WG and SPP modes by integrating a wavelength-scale periodically corrugated conductive photoresist into the device structure. The corrugated OLEDs with appropriate grating periods lead to a 15.9% increase in efficiency compared with the planar OLEDs. The efficient outcoupling of the WG and SPP modes is verified by the numerical simulation of both the emission spectra and the field distribution.
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Organic Light Emitting Materials and Devices

Organic Light Emitting Materials and Devices

This book should attract the attention of materials scientists, synthetic chemists, solid-state physicists, and electronic device engineers, as well as industrial managers and patent lawyers engaged in OLED-related business areas.

Author: Zhigang Rick Li

Publisher: CRC Press

ISBN: 9781439882801

Category: Science

Page: 813

View: 102

Organic Light-Emitting Materials and Devices provides a single source of information covering all aspects of OLEDs, including the systematic investigation of organic light-emitting materials, device physics and engineering, and manufacturing and performance measurement techniques. This Second Edition is a compilation of the advances made in recent years and of the challenges facing the future development of OLED technology. Featuring chapters authored by internationally recognized academic and industrial experts, this authoritative text: Introduces the history, fundamental physics, and potential applications of OLEDs Reviews the synthesis, properties, and device performance of electroluminescent materials used in OLEDs Reflects the current state of molecular design, exemplifying more than 600 light-emitting polymers and highlighting the most efficient materials and devices Explores small molecules-based OLEDs, detailing hole- and electron-injection and electron-transport materials, electron- and hole-blocking materials, sensitizers, and fluorescent and phosphorescent light-emitting materials Describes solution-processable phosphorescent polymer LEDs, energy transfer processes, polarized OLEDs, anode materials, and vapor deposition manufacturing techniques employed in OLED fabrication Discusses flexible display, the backplane circuit technology for organic light-emitting displays, and the latest microstructural characterization and performance measurement techniques Contains abundant diagrams, device configurations, and molecular structures clearly illutrating the presented ideas Organic Light-Emitting Materials and Devices, Second Edition offers a comprehensive overview of the OLED field and can serve as a primary reference for those needing additional information in any particular subarea of organic electroluminescence. This book should attract the attention of materials scientists, synthetic chemists, solid-state physicists, and electronic device engineers, as well as industrial managers and patent lawyers engaged in OLED-related business areas.
Categories: Science

Polymers for Light emitting Devices and Displays

Polymers for Light emitting Devices and Displays

Audience Engineers, polymer chemists, materials scientists, research scholars and graduate students working in the area of organic electronics, optoelectronics, and display technology, will find this book to be very useful.

Author: Inamuddin

Publisher: John Wiley & Sons

ISBN: 9781119654605

Category: Technology & Engineering

Page: 288

View: 673

Polymers for Light-Emitting Devices and Displays provides an in-depth overview of fabrication methods and unique properties of polymeric semiconductors, and their potential applications for LEDs including organic electronics, displays, and optoelectronics. Some of the chapter subjects include: • The newest polymeric materials and processes beyond the classical structure of PLED • Conjugated polymers and their application in the light-emitting diodes (OLEDs & PLEDs) as optoelectronic devices. • The novel work carried out on electrospun nanofibers used for LEDs. • The roles of diversified architectures, layers, components, and their structural modifications in determining efficiencies and parameters of PLEDs as high-performance devices. • Polymer liquid crystal devices (PLCs), their synthesis, and applications in various liquid crystal devices (LCs) and displays. • Reviews the state-of-art of materials and technologies to manufacture hybrid white light-emitting diodes based on inorganic light sources and organic wavelength converters.
Categories: Technology & Engineering

Realization of White Organic Light emitting Devices Using Single Green Emitter by Coupled Microcavities with Two Modes

Realization of White Organic Light emitting Devices Using Single Green Emitter by Coupled Microcavities with Two Modes

Abstract: We fabricated a novel white organic light-emitting diode (WOLED) structure based on a single green emitting layer through coupled microcavities with two modes.

Author:

Publisher:

ISBN: OCLC:1053749987

Category:

Page:

View: 916

Abstract: We fabricated a novel white organic light-emitting diode (WOLED) structure based on a single green emitting layer through coupled microcavities with two modes. By optical simulation and experiment, we showed that the two resonant modes can be adjusted by varying the thickness of the special layer to shape white light using only a single green emitter. Utilizing tris(8-hydroxyquinoline)aluminum (Alq3 ) as an emitting layer, we obtained a series of WOLEDs whose Commission Internationale de L'Eclairage (CIE) coordinates are on the Planckian curve from to with current efficiencies in the range of 1.45–2.52 cd A −1 . A maximum current efficiency of 10.12 cd A −1 and warm white emission at CIE have been demonstrated using bis(2-phenylpyridine)(acetylacetonate)iridium(III) [Ir(ppy)2 (acac)] as an emitter material.
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