Trends
Trends
LpR Article | Research
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Nov 28, 2016
The Perspective of Bio-Hybrid White Light-Emitting Diodes Based on Rubber-Like Down- Converting Coatings
At first, white LED technology seems to be mature. But in truth, the technology is still far from being perfect and research on all LED materials and components is ongoing. At the LpS 2016 the research of Rubén D. Costa, Lukas Niklaus, Katharina Weber and Prof. Uwe Sonnewald from the University of Erlangen-Nuremberg (FAU) was honored with the LED professional Scientific Award. These authors investigated the use of organic light conversion materials for white LEDs. Their research shows that these bio-hybrid white LEDs could lower costs and improve light quality. The article describes the current status of the research and future perspectives.
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Technologies | LECs | Light Generation
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Nov 28, 2016
LECs - The Light of the Future Thanks Nanostructures
In future they are to light up the inside of handbags or make evening joggers stand out in the dark: Light-emitting electrochemical cells, LECs, offer many advantages compared to familiar LEDs, but there's still something lacking – the right light. Until now only yellow light LECs are suitable for realistic use. But at least one other light colour is needed for more neutral light. Researchers in the Center for Nanointegration (CENIDE) of the University of Duisburg-Essen (UDE) have now been able to selectively change the colour for the first time and at the same time increase the performance of the LECs.
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LpR Article | Innovation
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Nov 24, 2016
On-Chip Beam Forming Optics Paves the Way for New Luminaire Designs
An LED luminaire’s optical system usually consists of primary and secondary optics. This concept always causes a trade-off between light quality, system size, efficiency and light distribution. New concepts to make secondary optics obsolete have already been researched. Paul Drosihn, Head of Modular Products, and Samir Mezouari, Optics & Lighting Design Specialist at Plessey Semiconductors present the first of its kind chip scale beam forming technology, StellarTM. They explain how it works and how it helps to overcome the limitations of traditional optical solutions for LED lighting.
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Technologies | OLEDs | Flexible OLEDs
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Sep 09, 2016
Researchers Propose Graphene Anode for Flexible OLEDs
In their research article, Tae-Hee Han, Min-Ho Park, Sung-Joo Kwon, Sang-Hoon Bae, Hong-Kyu Seo, Himchan Cho, Jong-Hyun Ahn and Tae-Woo Lee from the Pohang University of Science and Technology and the Yonsei University in Korea respectively investigated the use of praphene anodes for ultra-flexible OLED devices. The original article, "Approaching Ultimate Flexible Organic Light Emitting Diodes Using a Graphene Anode", is published in NPG Asia Materials (2016) 8, e303; doi:10.1038/am.2016.108 online on September 9, 2016.
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Lp Article | Technologies
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Sep 06, 2016
LightSpeed Experience Center
On August 26th, 2016 the editors of LED professional Review were invited by EBV Elektronik to visit their newly established “LightSpeed Experience Center” in Poing near Munich. It’s a very special meeting center, where you can view advanced and future technologies in the optoelectronics world. You could call it a tech incubator and think tank that enables innovation and creativity to combine.
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LpR Article | Technologies
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Sep 05, 2016
Technologies for Engineering an LED Light Closest to Sunlight
TRI-R is a next-generation LED light source made possible by Toshiba Materials technology and commercialization together with TOL STUDIO. Using natural light that recreates the solar spectrum, TRI-R suppresses glare, prevents the loss of object color, and gives fresher, clearer expression to textures and details. Based on professional research examining the relationship light has with humans and the environment, this is illumination technology that provides the world surrounding us with the true and real value of light. Masahiko Yamakawa, Senior Specialist of Toshiba Materials Co.LTD., presents how this technology was developed and applied in some projects.
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LpR Article | Research
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Aug 11, 2016
Quality and Health Aspects of LED Lamps for the European Residential Lighting Market
Because of shortfalls in regards to consumer information about high quality, energy efficient, substitute products for incandescent lamps, there has been a significant amount of irritation on the side of the consumer. As part of the Intelligent Energy Europe Program of the European Union, Prof. Dr. Georges Zissis from the Paul Sabatier - University Toulouse and his team investigated 370 LED lamps. All relevant parameters of 95 different lamp types from store shelves in 12 European countries were measured and evaluated regarding quality and health issues.
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LpR Article | Technologies | Medical
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Aug 11, 2016
High-End White Light Sources Fiber Optics Technology for Medical Applications
Often technologies that are too expensive for the mass market at the beginning are already adopted in medical applications. When reaching a certain level of maturity, costs usually become more reasonable and adaptations for the consumer market begins. Holger Laabs, Oliver Mehl and Henning Rehn from Osram GmbH present a light source technology and its prerequisites for fiber optics that could become one of these technologies.
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LpR Article | Technologies
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Aug 11, 2016
Concepts to Overcome Lifetime Issues of LED Drivers
Lighting technology has changed significantly in recent years after a century of little to modest advancements. LED luminaires offer advancement in lower power consumption and expected life. Maggie Nadjmi, EE Product Manager at SL Power Electronics, explains why this new technology will probably not meet the life and reliability expectations if no attention is paid to the drivers and power supplies used to power LEDs. She discusses the main components affecting lifetime and how to eliminate them or design a product to still achieve the desired lifetime.
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LpR Article | Research
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Aug 09, 2016
Flicker Beyond Perception Limits - A Summary of Lesser Known Research Results
Since the introduction of fluorescent lamps, the lighting industry knows about flicker issues. However, many aspects are still unclear. Especially effects beyond the flicker fusion threshold are mostly ignored, and sometimes even denied. Dr. Walter Werner, CEO of Werner Consulting, gives a summary of research results indicating that further research is needed and that for high quality lighting very likely a much higher PWM modulation frequency is required.
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Technologies | Thermal Management
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Jul 14, 2016
Engineered “Sand” May Help Cool Electronic Devices and LEDs
Giorgia Tech Research reports that Baratunde Cola, associated professor at the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology, would like to put sand into your computer and other electronic devices. Not beach sand, but silicon dioxide nanoparticles coated with a high dielectric constant polymer to inexpensively provide improved cooling for increasingly power-hungry electronic devices.
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Technologies | LEDs | Light Generation | Quality
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Jul 11, 2016
The Right Light for Fashion Retail, Fresh Food and Restaurants - More than just CCT and CRI
Lumileds recently introduced their Luxeon Stylist Series to support fashion, retail, fresh food sales and restaurants. Lumileds calls their proprietary technology for CoB LEDs CrispWhite Technology, CrispColor Technology™, FreshFocus Technology™ and AtmoSphere Technology™ depending on the focus. In preparation for the product release, Rick Hamburger, Senior Director of Product Management, Eric Senders, Product Line Director CoB, Luis Acena, Senior Manager, Luxeon Stylist Series, Kevin Lucido, Senior Director of Global Marketing Communications discussed the technology and features of the new product series with Arno Grabher-Meyer from LED professional.
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LpR Article | Technologies
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Jul 01, 2016
How Silicones are Evolving to Meet the Growing Needs of the LED Lighting Industry by Dow Corning
There are different materials for optics in lighting applications. The lighting application engineers François de Buyl, Martijn Beukema and Kevin van Tiggelen from Dow Corning are convinced that silicone’s unique qualities help to expand options in the design and molding of LED packaging components, as well as components for lamp and luminaire applications.
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LpR Article | Technologies
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Jun 29, 2016
Optical Lithography Method for Advanced Light Extraction in LEDs
Objective material selection for various target applications is key for successful product development. Efficient light extraction features are crucial for highly efficient LEDs. Thomas Uhrmann and Harun Solak, et.al* from EV Group and Eulitha AG will demonstrate a novel lithography method, PHABLE™, that enables the printing of sub-μm patterns in a non-contact, proximity process.
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LpR Article | Technologies
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Jun 28, 2016
High-Index Nanocrystals - Key to Next Generation Advancements in Lighting
Solid-State Lighting is destined to be a next generation lighting option. LEDs have already entered main stream applications and OLED technology has advanced greatly in the past few years in terms of efficacy and performance. Both technologies need to continue to improve performance to achieve high market acceptance. Dr. Gregory Cooper, Chief Technology Officer and Founder of Pixelligent Technologies LLC, illustrates how LED and OLED technology can advance to the next level by incorporating nanomaterials into existing packaging.
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LpR Article | Technologies
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Jun 28, 2016
MOCVD Platform for Cost-Effective Production of GaN-based HB LEDs
GaN-based blue and ultraviolet light emitting diodes (LEDs) are steadily becoming more widely used in solid-state lighting (SSL) applications [1-3]. Enabling dramatic energy savings when compared to contemporary incandescent bulbs and fluorescent lamps, these high-brightness LEDs (HB-LEDs) have a market potential in the billions of dollars. Yole Development estimates that by 2017, the market for LEDs will be approximately $75 billion [4, 5]. Shiping Guo, the Senior Technology Director of Advanced Micro-Fabrication Equipment Inc. presents a new approach to support this goal with a cost effective MOCVD solution for HB-GaN LED manufacturing.
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LpR Article | Technologies
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Jun 28, 2016
OLED Technology in Lighting Applications
Prototypes and niche applications with OLEDs for lighting have been demonstrated over the past few years. Now there are indications that OLED technology is ready for mass production or at least will be ready very soon. Franco Musiari, Technology Specialist at ASSODEL analyzed the current status and future perspectives of OLED technology.
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LpR Article | Technologies
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Jun 28, 2016
LED and Lens Degradation Through Volatile Organic Compounds
In general, LEDs are very resistant light sources. Nevertheless, glues, conformal coatings, o-rings, gaskets, and potting compounds, all materials that are frequently used in the construction of LED based luminaires or lamps and often contain volatile organic compounds (VOCs) may have a negative impact on performance, reliability and lifetime. Edward Steinke, application engineer at Cree, explains the set of problems and how to prevent these issues based on Cree’s products, using their test kit components, as well as components for lamp and luminaire applications.
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LpR Article | Technologies
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Jun 28, 2016
Reliability Oriented Design of LED-Based Light Sources
The transition from traditional light sources to SSL systems requires a different design philosophy to achieve the advantages offered by LED light sources. The key approach is based on the parallel design of thermal, electrical, optical and spectral properties of the light source. Matteo Meneghini, Gaudenzio Meneghesso, Enrico Zanoni and Matteo Dal Lago from the Department of Information Engineering at the University of Padova, and Nicola Trivellin from LightCube SRL explain this approach including the importance of the electrical management of LEDs, comparing modulation techniques to constant current, differentiating between versatility and efficiency.
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Technologies | LEDs | Light Conversion
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Jun 23, 2016
New Phosphor Promises Cheaper and more Efficient Next-Generation LED Lighting
Researchers from KU Leuven (Belgium), the University of Strasbourg, and CNRS have discovered a new phosphor that could make next-generation fluorescent and LED lighting even cheaper and more efficient. The team used highly luminescent clusters of silver atoms and the porous framework of minerals known as zeolites.
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Technologies | LEDs | Laser | Light Conversion | LiFi
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Jun 23, 2016
Perovskite Phosphor Provides High Quality White Light and Boosts VLC
Mark Peplow recently reported on the Chemical & Engineering News website about the latest encouraging research results from a research team from CEMSE and KAUST. The researchers found that combination of solution-processed CsPbBr3 perovskite nanocrystals (NCs) with a conventional red phosphor produces high quality white light when pumped with a blue LED or laser. Furthermore excited-state lifetime is short enough to provide record-breaking high bandwidth for visible light communication (VLC), aka LiFi.
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LpR Article | Technologies
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Jun 21, 2016
Safety Issues for LED Drivers with PWM Operation Modes by Product Approvals Ltd.
In many cases LED drivers manage their output power with PWM controlled switched mode power supply-topologies. The output voltages are filtered and normally DC voltages with low ripple apply at the output connectors of LED drivers. During dimming these circuits can behave very differently and therefore safety issues may arise. Siegfried Luger, CEO at Luger Research e.U. and John Showell, Product Safety Consultant at Product Approvals Ltd. have a closer look at those operation modes and the requirements on voltage limits.
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LpR Article | Technologies
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Jun 21, 2016
Optimization of SSL LED Devices by Osram Opto Semiconductors
There are different levers to improve LED performance. Ralph Bertram, application engineer for SSL products, and Alexander Wilm, key expert in the SSL application engineering department at Osram Opto Semiconductors, have a look into the device itself and explore the principal limitations of the different contributors to device efficacy. They show how to balance driving current and chip size to define the right LED, and explain the impact on performance and system costs of LED packages for the intended lighting task approaches for lighting strategies.
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LpR Article | Technologies
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Jun 20, 2016
LED Light Spectrum Enhancement with Transparent Pigmented Glazes
While LED bulbs have the distinct economic advantages of using less energy, producing less heat and lasting years longer than traditional incandescent bulbs, when objects are viewed under LED light, they frequently appear to be of different colors than when viewed in sunlight or with incandescent lights. Jan-Marie A Spanard from Light Spectrum Glazes proposes and explains an approach to optimize the spectral distribution of LED light to overcome this weakness.
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LpR Article | Technologies
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Jun 20, 2016
High Color-Rendering, Full-Visible-Spectrum LEDs by Soraa
The first wave of conventional white LEDs primarily focused on lumens per Watt. These LEDs were based on phosphor down-conversion using primary blue “pump” emission. Currently LEDs are catching up in regards to light quality using different approaches. Aurelien David, Senior Principal Scientist and Mike Krames, Chief Technology Officer at Soraa explain their technology approach of violet-pumped, full-visible-spectrum LEDs, and the interrelated challenges and advantages.
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Research
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Jun 09, 2016
Blue Wavelengths of LED Light Negatively Affect Milk Quality
Matt Hayes, managing editor and social media officer for the College of Agriculture and Life Sciences, and Alina Stelick, research support specialist in the Department of Food Science, report at the Cornell Chronicle of June 8th, 2016 that Cornell researchers in the Department of Food Science found exposure to light-emitting diode (LED) sources for even a few hours degrades the perceived quality of milk more so than the microbial content that naturally accumulates over time. Their study determined milk remained at high-quality for two weeks when shielded from LED exposure, and consumers overwhelmingly preferred the older, shielded milk over fresh milk stored in a typical container that had been exposed to LED light for as little as four hours.
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LpR Article | Technologies
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Jun 08, 2016
InGaN Nanowires Make Light Mixing Efficient and Smart
The correlated color temperature (CCT) of high color rendering index (CRI) LED lighting systems can, in principle, be tuned over a wide range. As an alternative approach to conventional phosphor based LEDs, a full-color LED array consisting of red, green and blue (RGB) InGaN based nanowire LEDs monolithically integrated on a micro-scale level has been proposed and fabricated. J. Lee from the Nano Electronics Lab at the Samsung Advanced Institute of Technology, Renjie Wang, Hieu P. T. Nguyen, Ashfiqua T. Connie, Ishiang Shih, and Zetian Mi from the Department of Electrical and Computer Engineering at McGill University in Montreal explain how this technology works and how the three multi-color subpixels on the same chip can be separately biased and can exhibit full-color emission which can be tuned controllably in a wide CCT range.
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LpR Article | Research
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Jun 08, 2016
A Graphene-Based, Spectrally Tunable, Flexible Field-Effect Light-Emitting Device by the Tsinghua University and the Tsinghua National Laboratory for Information Science and Technology
The continuous tuning of the emission spectrum of a single light-emitting diode (LED) by an external electrical bias is of great technological significance as a crucial property in high-quality displays and may be used in high quality lighting applications, yet this capability has not been demonstrated in existing LEDs. Graphene, a tunable optical platform, is a promising medium to achieve this goal. Xiaomu Wang, He Tian, Mohammad Ali Mohammad, Cheng Li, Can Wu, Yi Yang, and Tian-Ling Ren from the Institute of Microelectronics at the Tsinghua University in Beijing and the Tsinghua National Laboratory for Information Science and Technology (TNList) demonstrate a bright spectrally tunable electroluminescence from blue (~450 nm) to red (~750 nm) at the graphene oxide/reduced-graphene oxide interface.
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LpR Article | Technologies
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Jun 08, 2016
Mastering Thermal Issues in LED PCB Design & Laminate Selection by Ventec Europe
LED applications are not the only applications that are driving the need for thermal issues to be considered and mastered in PCB design, but they are certainly amongst the most challenging. Designing LED PCBs requires many considerations and key are those that arise from multiple heat sources in close proximity. Martin Cotton, Director OEM Technology of Ventec Europe describes the process and criteria used when designing PCBs (Printed Circuit Boards) for use in LED applications using thermally conductive IMS (Insulated Metal Substrates). He goes into technical detail with charts and diagrams that explain everything the designer would need to consider when selecting a laminate and commencing a design.
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LpR Article | Research
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Jun 07, 2016
Al2O3 Coated Europium- Activated Aluminum Silicon Nitride for COB LED Technology by the Graz University of Technology and Tridonic Jennersdorf
Eu2+ activated nitride phosphors have drawn much interest for solid state lighting because of their interesting photoluminescence. While they show excellent optical properties, they are hygroscopic and have the potential of being degraded by atmospheric moisture and high temperatures. A coating layer on the surface is an effective method to improve stability against moisture and oxidation. For use in chip on board technology, Nika Mahne, master student at the Institute of Inorganic Chemistry, A. Reichmann, B. Bitschnau, R. Fischer, from the Graz University of Technology, and F. Schrank from Tridonic Jennersdorf propose an approach where a CaAlSiN3:Eu2+ [1, 2, 3] phosphor was coated with Al2O3, obtained via a Brønsted precipitation reaction based on a solution-coating process from a mixture of aluminum halide with a base after annealing at a temperature of 400°C.
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