Technologies & Research

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 »

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 »

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 | 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 »

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 »

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 »

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 »

Technologies | LEDs | Monolythic RGB LEDs | Color-Tuning | May 02, 2019

Controlling Current, Duty Cycle and Pulses Allows Color Tuning in Monolithic GaN LEDs

A new technique - the result of an international collaboration of scientists from Lehigh University, West Chester University, Osaka University and the University of Amsterdam - could pave the way for monolithic integration for simple color tuning of a light bulb, according to Volkmar Dierolf, Distinguished Professor and Chair of Lehigh's Department of Physics who worked on the project. Read more »

Technologies | Thermal Management | Material Science | Polymers | Apr 30, 2019

MIT Researchers Developed New Heat Conducting Polymer Films

Polymers are usually the go-to material for thermal insulation. Think of a silicone oven mitt, or a Styrofoam coffee cup, both manufactured from polymer materials that are excellent at trapping heat. Now MIT engineers have flipped the picture of the standard polymer insulator, by fabricating thin polymer films that conduct heat — an ability normally associated with metals. In experiments, they found the films, which are thinner than plastic wrap, conduct heat better than many metals, including steel and ceramic. Read more »

Technologies | Light Conversion | Phosphors | White LEDs | Apr 24, 2019

Energy-Saving New Red LED Phosphor Developed at University of Innsbruck

The human eye is particularly sensitive to green, but less sensitive to blue and red. Chemists led by Hubert Huppertz have now developed a new red phosphor whose light is well perceived by the eye. This increases the light yield of white LEDs by around one sixth, which can significantly improve the energy efficiency of lighting systems. Read more »

TU Vienna - New Method to Generate Light from Exotic Particle States

A new type of light-emitting diode has been developed at TU Wien. Light is produced from the radiative decay of exciton complexes in layers of just a few atoms thickness. Read more »

Standardized Programming of Lighting Components Using NFC Technology

LpR 70 Article, page 88: NFC programming of LED drivers is rapidly gaining popularity as a fast, feature-rich, flexible and easy method to set the operating characteristics of LED drivers inside luminaires. Arnulf Rupp, Chair of MD-SIG, describes how the MD-SIG specification for NFC programming of lighting components makes it easy for luminaire manufacturers to use NFC programming in a production line where multiple brand drivers are used one after the other. Read more »

Bluetooth Mesh Protocol as Applied to Lighting

Little more than one year ago, Bluetooth SIG released the Bluetooth Mesh standardization. Meanwhile, it has become widely adopted and is also one of the favorite systems for lighting controls. Russ Sharer, Vice President of Global Marketing and Business Development for Fulham, starts with an explanation of the Bluetooth Mesh protocol as applied to lighting control and defining its key elements. In a second portion of the article, he answers questions that lighting control evaluators could be asking their vendor. Read more »

3D Bio-Optical Models Reveals How the Human Body Uses the Entire Solar Spectrum

History teaches that global changes to the public's environment mandate a higher level of scrutiny to ensure that we first do no harm. In "Melatonin and the Optics of the Human Body" published in the journal Melatonin Research, Zimmerman and Reiter combine optical ray tracing from lighting and ESR data from the medical industry to model for the first time the 3D free radical distributions generate by lighting sources in the human body. Read more »

An Old Story Re-Edited? - Firefly-Inspired Surfaces Improve LED Efficiency

A new type of light-emitting diode lightbulb could one day light homes and reduce power bills, according to Penn State researchers who suggest that LEDs made with firefly-mimicking structures could improve efficiency. Read more »

Resources | LpR Article | Technologies | Thermal Management | Feb 01, 2019

Materials, Manufacturing and Technologies for Designing Passive Cooling Devices

Until recently, incandescent bulbs and fluorescent lights were the dominant light sources. Today it’s the energy efficient, durable and, in the meantime, cost effective, LED. But to achieve these attributes appropriate cooling is still necessary and due to progress over the last few years the need for active cooling solutions is limited to a few high power applications as long as the material and technology is carefully chosen. John Broadbent, Managing Director at Columbia-Staver Ltd., describes the different technologies and materials and gives practical advice on how to find the right solution for an application. Read more »

Qualified Bluetooth Mesh – Making Lighting Controls Future-Proof

LpR 69 Article, page 88: At Lightfair USA, Siegfried Luger met with Patrick Durand, Worldwide Technical Director at Future Lighting Solutions. One of Mr. Durand’s striking statements was: “Basically, what we need is to future-proof lighting control.” This was the first time that this important aspect was so clearly addressed by a representative of the industry. This led us to asking Mr. Durand to provide LED professional with a technical article to clarify the current situation, explain the technical background that led him to making that statement and to give an idea of which requirements a controls solution must fulfill to be truly future-proof. Read more »

The Possible Future of Lighting - Paint-On Semiconductors from Ornate Quantum Physics

LED lights and monitors, and quality solar panels were born of a revolution in semiconductors that efficiently convert energy to light or vice versa. Now, next-generation semiconducting materials are on the horizon, and in a new study, researchers have uncovered eccentric physics behind their potential to transform lighting technology and photovoltaics yet again. Read more »

Colloidal Quantum Dots Make LEDs Shine Bright in the Infrared

ICFO researchers report on the development of a colloidal quantum-dot light emitting diode with unprecedented quantum and power conversion efficiencies in the infrared range. The ideal optoelectronic semiconductor material should be a strong light emitter i.e. should emit light very efficiently upon optical excitation as well as be an efficient charge conductor to allow for electrical injection in devices. These two conditions when met can lead to highly efficient light emitting diodes as well as to solar cells with the possibility to approach the Shockley-Queisser limit. Until now the materials that have come close to meeting these conditions have been based on epitaxially-grown costly III-V semiconductors that cannot be monolithically integrated to CMOS electronics. Read more »

How to Use the Technologies for Adaptive Lighting

The technologies to provide adaptive lighting are already in the marketplace and are accepted by some jurisdictions. Nonetheless, we have an inadequate understanding of how best to use these technologies, meaning that installations might not serve users well, and in the worst case, might lead to harm. Lighting researchers can generate the knowledge needed to support the best application of adaptive lighting technologies. The International Commission on Illumination (CIE) understands the importance and urgency to deal with problems of adaptive, dynamic and intelligent lighting in all application fields. Hence, this topic is a highlight of CIE’s research strategy. Read more »

Researchers Push Perovskite LEDs' Efficiency To Rivaling Best OLEDs

Compared to OLEDs, which are widely used in high-end consumer electronics, the perovskite-based LEDs, developed by researchers at the University of Cambridge, can be made at much lower costs, and can be tuned to emit light across the visible and near-infrared spectra with high colour purity. Now, researchers have set a new efficiency record for LEDs based on perovskite semiconductors, rivalling that of the best Organic LEDs (OLEDs). Read more »

Researchers from the University of Surrey Find that Blue Light Can Reduce Blood Pressure

Exposure to blue light decreases blood pressure, reducing the risk of developing cardiovascular disease, a new study from the University of Surrey and Heinrich Heine University Duesseldorf in collaboration with Philips reports. Read more »

New Algorithm Can More Quickly Predict Phosphor Materials for LEDs

Jakoah Brgoch, assistant professor of chemistry at the University of Houston, and members of his lab published a paper on Oct. 22 in Nature Communications describing how machine learning speeds discovery of new materials. By scanning a huge number of compounds for their key attributes they were looking for a new light conversion material that could be used in white LEDs. Read more »

UV LED Technology for Emerging Applications in Agriculture

The Ultraviolet (UV) LED market has expanded five-fold in the past decade and is projected to grow to over $1 billion by 2025. A key trend expected to influence the market is the ability to expand into new applications, including agriculture. UV light, at proper frequency and dose, can increase the production of active substances in medicinal and traditional plants and it can also help maintain a healthy growing environment. But to fully take advantage of UV LEDs, some major re-design considerations are required. Terrance Berland, CEO of the Violet Defense Group, the parent company of Violet Gro, will explain which considerations these are; for instance, why it is crucial to incorporate the appropriate lens material. Read more »

Spanish Researchers Develop Sand that Produces White Sun-Like LEDs

The team led by the chemist-technologist Rubén Costa of IMDEA Materials (Madrid) and the chemists Jesús Berenguer of the University of La Rioja and Javier García of the University of Alicante has overcome one of the biggest obstacles in the progress towards new sources of healthier artificial lighting. Read more »

Dynamic In-Car Lighting Scenarios - Osram's Osire E4633i Prototype with Inova's Serial Control Driver

The more autonomous a car becomes, the more the way in which it is used will change. As developments continue toward autonomous driving, more and more attention is being focused on the passenger cell. Light will become an integral part of the passenger cell, taking on functional and design-specific tasks. Previously static light, which could only be switched on and off, has now been given a dynamic dimension with the prototype of the Osire E4633i – with countless design options for car manufacturer. Read more »