Trends

Hermetic Polymer-Free White LEDs for Harsh Environments

AlGaInN-based white LED can easily achieve lifetimes of up to 100,000 h depending on junction temperature and current density. However, state of the art silicone encapsulated LEDs with powder-based phosphors reveal a strong dependence of field lifetimes on environmental conditions such as humidity, corrosive gas and air pollutant exposure. Dr. Michael Kunzer, Group Leader LED Modules at Fraunhofer Institute for Applied Solid State Physics and his colleagues, Ralf Schmidt, Andreas Zibold, Vasileios Georgiou-Sarlikiotis, Michael Arnold and Isabel Kinski propose luminescent ceramics as an interesting alternative to polymer-dispersed phosphors. This provides entirely new opportunities for the manufacturing of white LEDs. The authors explain the properties and advantage of this hermetic, light converting cap material and how to completely avoid polymers. Read more »

A New Approach for Fast and Accurate Measurement of Light Emitting Diodes Junction Temperatures

LpR 73 Article, page 48: Junction temperature of LEDs is one crucial parameter to being thoroughly observed. In this paper, Ahmet Mete Muslu, Onuralp Isil and Prof. Mehmet Arik from the Energy Efficient Electronics and Lighting Technologies Center (EVATEG), Department of Mechanical Engineering at the College of Engineering Ozyegin Universitywill at first describe the importance of Tj for LED systems including RGB and white LEDs. Then they will present techniques from literature and recently in-house developed novel methods and a new Junction Temperature Measurement Device (EVAtherm). Results in selected general lighting and automotive lighting applications will be demonstrated. Read more »

Flickering Light Mobilizes Brain Chemistry that May Fight Alzheimer's

For over a century, Alzheimer's disease has confounded all attempts to treat it. But in recent years, perplexing experiments using flickering light have shown promise. The promise of flickering light to treat Alzheimer's takes another step forward in this new study, which reveals stark biochemical mechanisms: 40 Hertz stimulus triggers a marked release of signaling chemicals. Read more »

ENABLED – A New Funded Research Program to Design Fluorescent Proteins for White LEDs

A joint research project between Spain, Italy and Austria will work to replace inorganic phosphor filters in LEDs by those nature uses deed down the sea. The ENABLED project, coordinated by the Spanish research center IMDEA Materials Institute, has a budget of € 2.7 million euros, will run for the next 3 years and is funded by the European Commission under the Future and Emerging Technologies programme. Read more »

Technologies | Light Generation | LEDs | Phosphors | Jan 22, 2020

Researchers from Hokkaido University Let Europium Shine Brighter

A stacked nanocarbon antenna makes a rare earth element shine 5 times more brightly than previous designs, with applications in molecular light-emitting devices. - The europium Eu(III) complex with nanocarbon antenna emitting fine red light. Read more »

Technologies | Horticulture | Standardization | Jan 09, 2020

Researchers Call for Greenhouses LED Lighting Standards

While LED lighting can enhance plant growth in greenhouses, standards are needed to determine the optimal intensity and colors of light, according to Rutgers research that could help improve the energy efficiency of horticultural lighting products. Read more »

Technologies | Micro-LEDs | LED Modules | Displays | Jan 09, 2020

SSC Develops World's First One Pixel Micro LEDs for 4K Resolution TV from 42" to 220"

Seoul Viosys Co., Ltd. (CEO Young Joo Lee) and Seoul Semiconductor Co., Ltd. (CEO Chung Hoon Lee), leading global innovators of LED and UV LED technologies, announced the new concept display, 'Micro Clean LED' at CES 2020, the biggest global consumer electronics and technology show, running from January 7th through January 10th. Read more »

HCL-Research | HCL | Health + Environment | Dec 19, 2019

Research Confirms that Light Pollution Can Suppress Melatonin Production in Humans and Animals

Melatonin sets the internal clock. Researchers from IGB in an international team have analyzed data on the impact of light pollution on melatonin formation in humans and vertebrates. They found that even the low light intensities of urban skyglow can suppress melatonin production. Melatonin influences the metabolism and other body functions. Read more »

HCL | HCL-Research | Biological Effects | Health | Dec 18, 2019

University of Manchester Scientists Suggest Blue Light Not So Disruptive to Sleep as Thought

Contrary to common belief, blue light may not be as disruptive to our sleep patterns as originally thought. According to the team, using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial to our health. Twilight is both dimmer and bluer than daylight, they say, and the body clock uses both of those features to determine the appropriate times to be asleep and awake. Read more »

HCL | HCL-Research | Health | Dec 18, 2019

Tailored Light Improves Sleep Quality, Depression, Agitation in Older Adults with Alzheimer's Disease

Most people associate Alzheimer's disease with profound memory loss, but it is often the symptoms - sleep disturbances, depression, and agitation - that are a challenge to treat, and can significantly reduce the quality of life for both the affected individual and their family members and caregivers. In a research project funded by the National Institute on Aging (NIA), Dr. Mariana Figueiro, Professor and Director at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute, is investigating whether a tailored lighting intervention can lessen the impact of these symptoms in older adults living with Alzheimer's disease and related dementias (ADRD). Read more »

Resources | Tech-Talks Bregenz | Laser Technology | Dec 16, 2019

Tech-Talks BREGENZ - Julian Carey, Marketing Manager at SLD Laser

In 2016, Nobel Laureate, Professor Shuji Nakamura held a key note speech at LpS. As the founder of Soraa and SLD Laser, he named laser lighting as the next, innovative step and disruption in lighting. He emphasized the need to focus on light quality and the tailoring of LED lighting to the natural needs of humas, providing light that mimics sunlight as closely as possible. It was therefore self-evident that LED professional would invite Julian Carey, the Product and Technical Marketing Manager at SLD Laser, for a Tech-Talk when he was at the LpS 2018 in Bregenz. We asked him for an update on the status of laser lighting, business strategies and future prospects and how laser lighting has developed since Professor Nakamura's statements in 2016. Read more »

Hella Announces Development of High-Resolution Lighting System Digital Light SSL|HD

With the new high-resolution lighting system "Digital Light SSL|HD", the lighting and electronics expert HELLA is making a further significant contribution to greater safety and comfort in road traffic. With this lighting technology, more than 30,000 pixels can be controlled intelligently and individually, thus bringing about numerous new safety functions like optical lane markings. Furthermore, original equipment manufacturers and end customers can use SSL|HD technology to implement and experience further options allowing enhanced individualisation, such as coming and leaving home animations as well as communication functions. Read more »

Vitrek's New Ultra High Accuracy Power Analyzer Sets New Standard for Price/Performance

Vitrek, the leader in high-voltage test and measurement equipment, introduces the PA920 Series Ultra High Accuracy Power Analyzer. The PA920 sets the new standard for accuracy (0.024% of reading) in the graphical power analyzer market. It integrates an ultra-high accuracy, wideband waveform digitizer with advanced computational capability, a large high-resolution display and a full-color touchscreen user interface. Read more »

Chinese Researchers Propose Method to Overcome Low Efficiency of High-Power Flip-Chip LEDs

Chinese scientists from different research centers recently published a co-authored paper on "Highly Efficient GaN-based High-Power Flip-Chip LEDs" in Optics Express Vol. 27, Issue 12, pp. A669-A692 (2019)under the terms of the OSA Open Access Publishing Agreement. High-power flip-chip light-emitting diodes (FCLEDs) suffer from low efficiencies because of poor p-type reflective ohmic contact and severe current crowding, they propose an improvement by using an Ag film. Read more »

Cree Expands Design Possibilities for Architectural Lighting with the Worldwide Proven CLQ6A LED

These SMD LEDs are packaged in an industry standard PLCC8 package. These high performance 4 color SMT LEDs are designed to work in a wide range of applications. A wide viewing angle and high brightness make these LEDs suitable for signage applications. Read more »

Study Reveals How Age Affects Perception of White LED Light

Although LEDs are increasingly used in low-energy lighting and displays, consumers sometimes find their light harsh or unpleasant. Findings from a new study point to the need to take age-related perception differences into account when designing white LED lighting that is more pleasing to the eye. Read more »

BTS256-EF Measures New Flicker Metrics for Compliance with Ecodesign Directive

The European Commission´s proposed regulation of lighting under the Ecodesign Directive will establish mandatory product performance and quality requirements on all lighting products. This new EU directive will include strict requirements for flicker and stroboscopic effect, collectively referred to as temporal light artefacts (TLA). Simple measures such as flicker index and modulation depth will not be adequate as they do not distinguish the possible TLA effects and do not account for the effect of frequency-dependent sensitivity or the wave shape of light output. The BTS256-EF spectral light and flicker meter measures the specific metrics required by the regulation, PstLM and SVM. Read more »

Plessey - Native Blue and Native Green Emission microLEDs from the same Wafer

Plessey, an embedded technologies developer at the forefront of microLED technology for augmented and mixed reality (AR/MR) display applications has extended the capability of their proprietary GaN-on-Silicon process to enable Native Blue and Native Green emission from the same wafer. Read more »

Fraunhofer Shows Modular OLED Light Strips

At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37. Read more »

Resources | LpR Article | Research | Thermal Management | Sep 17, 2019

Thermal and Optical Challenges for SSL in Automotive Applications

LpR 72 Article, page 50: Solid State Lighting changed the lighting environment in automotive lighting almost more than in the field of general lighting. While efficiency of the devices increased and every few weeks new improvements are reported, thermal management remains crucial and a critical part of the system. Umut Zeynep Uras, Ahmet Mete Muslu and Mehmet Arik, from the Energy Efficient Electronics and Lighting Technologies Center (EVATEG), Department of Mechanical Engineering, College of Engineering at Ozyegin University, and Fatih Goren from the FARBA Corporation, explain the dependencies between photometric, electrical and thermal parameters of an automotive lighting application. Read more »

Resources | LpR Article | Technologies | DC-Grids | Sep 17, 2019

LED Lighting Systems in Smart Buildings with DC Microgrids

LpR 72 Article, page 60: While electric motors for ventilation and air-conditioning systems were already DC-based in the past, powerful IT systems, LED lighting systems, photovoltaic systems with batteries and charging systems for electro mobility are now increasingly being used in modern building environments. They all need direct current (DC). Therefore, an obvious step is to equip modern buildings with DC grids. Carsten Moellers from Abalight discusses a number of unresolved questions and presents possible solutions in this article. Read more »

Resources | LpR Article | Research | Micro-Optics | Aug 13, 2019

Semi-Empirical Characterization of Freeform Microlens Arrays

LpR 72 Article - page 42: Microlens arrays (MLA) have been used for imaging and non-imaging applications for a long time as cost-effective solutions. Non-symmetrical beam shapes require more advanced non-symmetrical freeform microlens arrays (FMLA). The required FMLA molding tools convey a high cost and an iteration process is required for the final design. Oscar Fernández, Tamara Aderneuer, Rolando Ferrini from the Centre Suisse d'Electronique et de Microtechnique, CSEM, and Julien Duchene from ANSYS proposed a method to overcome these limitations based on 3D surface sampling, computer generation of a ray-traceable model and ray-tracing performance simulation and demonstrate feasibility for several commercially available freeform asymmetric thin-film diffusers. Read more »

High Performance from Extraordinarily Thick Organic Light Emitting Diodes with Perovskite Layers

By combining thin organic layers with thick layers of hybrid perovskite, researchers at Kyushu University in Japan have developed micrometer-thick organic light-emitting diodes that could improve the affordability and viewing angles of high-performance displays and televisions in the near future. Read more »

ALAN May Be Increasing West Nile Virus Spillover from Wild Birds

We're in the midst of summertime mosquito bite season and cities across the country are reporting a heightened number of West Nile Virus (WNV) cases. The house sparrow is one of the most common carriers of WNV in urban areas. Mosquitos feed off the infected birds and spread the virus to humans. New research finds house sparrows exposed to artificial light at night, such as what's used in parking lots, maintain higher burdens of WNV for longer than those who spend their nights in the dark. Read more »

Flex LED Based Smart Light System for Healing of Chronic Wounds

LpR 71 Article - page 48: Chronic wounds are notoriously challenging to treat, because they do not follow the typical healing process or time-frame. The resulting burden is significant, affecting over 40 million patients. Blue light is known for its anti-microbial and anti-inflammatory effects in the initial stages of the healing process. David Kallweit, researcher at CSEM, reports about the joint development of a chronic wound treatment device with their MEDILIGHT partners, URGO RID, University of Heidelberg, SignalGenerix, Microsemi, Technical University of Berlin, and Amires. He furthermore shows how it works and discusses future prospects. Read more »

Technologies | Smart Lighting + IoT | Resources | LpR Article | Jul 29, 2019

Voice Controlled Lighting that Protects Privacy and Data

LpR 71 Article - page 54: Intelligent lighting systems undoubtedly offer high comfort and energy efficiency. But especially conventional voice control systems like Amazon Alexa, Apple Siri or OK Google, with connected lamps and lighting fixtures are also becoming targets for uninvited guests. The benefits and technology of a new approach offering local voice control and artificial intelligence will be explained by Genia Shipova, Director Global Communications at Snips. Read more »

Thermal Management | Forge Europe | Technologies | Jun 11, 2019

Get Your Thermals Sorted

Long-lasting LED solutions require superb thermal design – Forge ensures the thermal design is a fundamental design process for every LED solution they manufacture. Read more »

LEDs | Solar Systems | Technologies | Jun 04, 2019

Organic Solar Cells and Light-emitting Diodes United

In the past 25 years of research on organic semiconductors, it was thought that organic solar cells and organic light-emitting diodes (OLEDs) could not be combined in a single device. A team of physicists headed by Prof. Koen Vandewal from Technische Universität Dresden has now succeeded in manufacturing an organic solar cell that simultaneously functions as an efficient OLED. Their findings were recently published in the internationally renowned journal Nature Materials. Read more »

Implications for Human-Centric Lighting Design in Tropical Nursing Homes: A Pilot Study

Light synchronizes our physiological and psychological rhythms to the 24-hour rhythm of the ambient changes. For the elderly, adequate environments to compensate for increasing frailty and sensory loss are crucial. Dr. Szu-Cheng Chien, Assistant Professor at the Singapore Institute of Technology reports from a pilot study that aimed to explore HCL design strategies in nursing homes in Singapore. Pre-/post implementation user surveys and quantitative evaluations were conducted. Read more »

Scientific Study Demonstrates Positive Effects of Daylight LED on Visual Comfort, Melatonin, Mood, Waking Performance, and Sleep

There has been an increase in research activity on the relationship between light and human bio-function, including a recent scientific study focusing on the effects of light spectrum on sleep quality, visual comfort, well-being and daytime alertness conducted by Prof. Christian Cajochen and his team at the University of Basel in Switzerland, entitled: "Effect of Daylight LED on Visual Comfort, Melatonin, Mood, Waking Performance, and Sleep." Read more »