White Papers

White Paper | Technology | Jan 09, 2015

Compute Simulation Sheds Light On Why Blue LEDs Are So Tricky To Make

New research from academics from the University of Bath Department of Chemistry has uncovered the mystery of why blue light-emitting diodes (LEDs) are so difficult to make: (1) Calculated spin density resulting from (a) a Mg0Ga-associated hole localized on a neighboring N in the basal plane, (b) a Mg0Ga-associated hole localized on a neighboring axial N, and (c) a N vacancy. Light gray (green) [darker gray (blue)] spheres represent Ga (N) atoms. The darkest gray sphere represents a Mg atom in (a) and (b) (purple) and a vacancy in (c) (orange). Spin densities are indicated by (red) isosurfaces of density (au) 0.05, 0.025, and 0.01 for (a) and (b) and 0.01, 0.005, 0.0025 for (c). (2) Formation energy of VN (black line) and MgGa [light gray (red) line] as a function of Fermi energy above the VBM. Anion-rich conditions are assumed. The position of the conduction band minimum (CBM) is indicated by the broken line. For each value of Fermi energy, only the most stable defect charge state is shown, with a change in slope indicating a change in charge state Researchers in our Department of Chemistry have collaborated with groups at University College London (UCL) and Daresbury to uncover the mystery of why blue light-emitting diodes (LEDs) are so difficult to make, by revealing the complex properties of their main component – gallium nitride – using sophisticated computer simulations. Read more »

White Paper | Standardization & Regulation | Dec 11, 2014

Zhaga Consortium Starts Work on New Specification for COB LED Arrays

Zhaga is now writing a Book on COB LED arrays In response to feedback from a broad range of stakeholders, the Zhaga Consortium, which develops specifications for interchangeable LED light sources, is now working on a new Book that will include Chip-on-Board (COB) LED arrays. The new Zhaga Book will specify a family of six rectangular or square LED modules with different dimensions. Read more »

White Paper | Technology | Nov 21, 2014

Thermoresponsive PDLC Coating for Smart CCT-Tunable LED Applications

Thermoresponsive scattering coating for smart CCT-changing white LEDs: a) basic working mechanism; b) demonstrator using coated (bottom) and uncoated (top) warm white LEDs operating at a low current (~20 mA/LED - top picture) and at a high current (~80 mA/LED - the bottom); c) associated CCT vs. current diagram When the 2014 Nobel Prize in physics was awarded this October to three Japanese-born scientists for the invention of blue light emitting diodes (LEDs), the prize committee declared LED lamps would light the 21st century. Now researchers from the Netherlands propose a novel way to ensure the lights of the future not only are energy efficient but also emit a cozy warmth. Cornelissen and his colleagues from the Eindhoven University of Technology, Netherlands describe their new LEDs in a paper published in The Optical Society's (OSA) open-access journal Optics Express. Read more »

Resources | White Papers | Optics & Opt. Materials | Engineering | Simulation Tools

WHITE PAPER: "Optimization of LED Lens Components using TracePro® Illumination Design and Analysis Software"

Side Emitting lens and reflector combination initial configuration with large angular output and 62% efficiency. TracePro® is award-winning opto-mechanical design software for layout, optimization, & analysis of illumination systems. This white paper illustrates how TracePro’s 2D & 3D optimization utilities are designed to help CAD designers without optical engineering expertise design a variety of LED optical components – including practical examples. The capabilities of TracePro lead the designer through a process to maximize the technical merits of the device/system in the shortest amount of time. Read more »

White Paper | Technology

WHITE PAPER: Intelligent Over Temperature Protection for LED Lighting Applications

Application circuit with the new ILD6070 driver: The current reduction is triggered at a threshold of the solder point temperature of the LED driver IC which is adjustable using an external resistor connected to the Tadj pin LED lighting is becoming increasingly popular. It offers numerous advantages over conventional lighting, but there are still some issues. One is thermal management. Bernd Pflaum and Hakan Yilmazer from Infineon Technologies explain how LED driver ICs with smart over temperature protection help to increase lifetime and optimize system costs of LED lighting systems. Read more »

White Paper | Technology | Aug 28, 2014

Osram Opto Demonstrates "3D nano LEDs" for White Light and Sees Series Maturity in Coming Years

Osram researchers make a 3D nano LED for white light shine on the wafer using two tiny, energized needles.The needles are pressed onto the contact surfaces of the chips, and the distance between the contact points corresponds approximately to the thickness of three sheets of stacked writing paper By making use of nanotechnology, Osram hopes to produce significantly more LED chips with its existing production plant. Osram researchers have for the first time succeeded in manufacturing a so-called "3D nano LED" for white light. The productivity boost is possible due to the special surface characteristics of the LED chip – in contrast to today's standard models, this is not smooth but consists of many adjacent, microscopically small columns with a three-dimensional structure, thus increasing its light-generating area. The new technology is expected to achieve series maturity in coming years, and Osram would then be one of the first companies to use this technology. Read more »

White Paper | IP, Reports & Roadmaps | May 22, 2014

Yole Releases New Nanowire LED IP Study - Startups Compete with Asian LED Giants in the IP Landscape

Timeline of patent publications for active devices Asian giants Samsung, Panasonic and LG are the top three patent assignees for Nanowire LED technology. Facing them are several startups including glo, Aledia and Ecospark, which between them have raised more than $150M - thus confirming their serious interest in this field. However, these newcomers face strong technological challenges. Read more »

White Paper | IP, Reports & Roadmaps | Apr 23, 2014

GaN-on-Silicon Substrate Patent Investigation - Knowmade & Yole See More Players on the Playground

Evolution of patent publications related  to GaN-on-Si technology from the earliest beginning in the seventies until today GaN-on-Si technology appeared naturally as an alternative to GaN-on-Sapphire—the main stream technology for LED applications. Today, despite potential cost benefits, the mass adoption of GaN-on-Si technology for LED applications remains unclear. Most major LED makers have a patenting activity related to GaN-on-Si technology, but so far, few have made it the core of their strategy and technology roadmap. Contrary to the LED industry, we expect GaN-on-Si to be widely adopted by Power Electronics and RF applications because of its lower cost and CMOS compatibility. Read more »

White Paper | Standardization & Regulation | Apr 08, 2014

EEPCA & LightingEurope Announce ENEC+ - The First European Mark That Certifies the Initial Performance of LEDs and Other Luminaires

ENEC+ is complementary to the ENEC Mark EEPCA, the European Electrical Products Certification Association, in cooperation with LightingEurope, today announced the launch of ENEC+, the first pan-European mark capable of certifying the initial performance of traditional and LED luminaires. The new performance rating provides the market with certification as to the compliance of LED light fixtures and other luminaires, proving compliance with European safety standards and ensuring the reliability of their stated performance characteristics at the beginning of their life cycle. Read more »

White Paper | Standardization & Regulation | Apr 08, 2014

Zhaga Starts Work on New Books

The Zhaga Consortium, which develops specifications for interchangeable LED light engines, has started to write Books 9, 10 and 11 The Zhaga Consortium, a global lighting-industry organization that is enabling interchangeable LED light engines, has started the development of three new interface specifications, known as Books. The new Books are designated numbers 9, 10 and 11. Read more »

White Paper | IP, Reports & Roadmaps | Mar 20, 2014

Yole Développement's GaN-on-Si Report Forecasts Future of power Electronics and LEDs

Voltage and current requirements for different applications and the GaN-on-Si power device development status at the present time Yole Développement releases this week the GaN-on-Si Substrate Technology and Market for LED and Power Electronics report. Under this report, Yole Développement reviews the GaN-on-Si technology growth, challenges and solutions. Dr Hong Lin and Dr Eric Virey, Yole Développement’s analysts give an overview of GaN-on-Si epiwafer playground. This report also provides an in-depth analysis of the GaN-on-Si technology for LED and power electronic applications, including technology and cost aspect. Yole Développement’s analysts, both develop possible business models for the adoption of GaN-on-Si technology. GaN-on-Si substrate technology and market for LED and Power Electronics report also includes market volume and revenue forecast to 2020. Read more »

White Paper | Standardization & Regulation | Mar 17, 2014

Zhaga Aims to Enable Independent Interchangeability of LED Modules and Drivers

Current situation: According to current Zhaga Books, full interchangeability applies only to the complete LED light engine (LLE). It may not be possible to interchange the LED module(s) without also changing the driver, or vice versa. Future situation: Zhaga aims to enable full and independent interchangeability of LED modules and drivers The Zhaga Consortium, which develops specifications for interchangeable LED light engines, has decided that it will also aim to enable LED modules and drivers that are independently interchangeable. This is in addition to Zhaga’s stated aim to enable interchangeability of LED light engines. Read more »

White Paper | Technology | Mar 13, 2014

Quantum Materials Secures Los Alamos Thick-Shell Quantum Dot Technology to Increase Brightness

Quantum materials optioning Thick-Shell 'Giant' Quantum Dot patented technology promises improvement in solid-state brightness over conventional nanocrystal quantum dots (QD) Quantum Materials Corporation and Los Alamos National Laboratory's today announce Quantum Materials optioning Thick-Shell 'Giant' Quantum Dot patented technology with the potential of 10 to 100-fold improvement in solid-state brightness over conventional nanocrystal quantum dots (QD). High brightness leads to efficient use of materials and increased performance in electronic displays and solid state (LED) lighting. Read more »

Fundings & Projects | White Paper | Feb 13, 2014

New Research Initiative: LASSIE-FP7 To Develop LED-Based Modules for Professional and Architectural Lighting

CSEM announces the launch of LASSIE-FP7, a research project funded by the European Commission to develop a unique integrated solid-state module that will constitute a breakthrough in professional and architectural lighting. Read more »

Fundings & Projects | White Paper | Feb 11, 2014

CPI Manufactures Flexible OLED Lighting Demonstrators

The Centre for Process Innovation (CPI) has produced a range of flexible Organic Light Emitting Diode (OLED) demonstrators on substrates with thickness ranging from 50µm to 125µm The Centre for Process Innovation (CPI) has produced a range of flexible Organic Light Emitting Diode (OLED) demonstrators. Manufactured on CPI’s OLED/OPV Prototyping Line, the devices have been built on a range of substrates with thickness ranging from 50µm to 125µm. The device structure consists of an Indium Tin Oxide anode, evaporated hole injection layer, co-evaporated emissive layer and a conventional cathode. The device chemistry can be modified to produce a variety of colours and is encapsulated using a pressure sensitive adhesive and a commercially available barrier material. Read more »

White Paper | Products, Materials & Tools | Feb 11, 2014

WHITE PAPER: "LED Reflector and Lens Simulation using TracePro® Illumination Design and Analysis Software"

Luxeon LED as modeled as a surface source using the Tracepro Bridge in SolidWorks TracePro® is award-winning opto-mechanical design software for layout, optimization, & analysis of illumination systems. This white paper illustrates how TracePro allows users to begin a project with an initial or basic design for LED lighting systems, use software simulation prior to building hardware, and easily create complex reflector shapes. TracePro’s reflector and lens simulation utilities are specifically designed to help CAD designers without traditional optical engineering expertise design LED optical components quickly. Read more »

White Paper | Technology | Jan 24, 2014

Cree Sets New Efficiency Benchmark with First 200 lpw LED Luminaire Prototype

Cree, Inc. raises the performance bar again with the demonstration of the first 200 lumen-per-watt (LPW) LED concept luminaire, which is more than twice the efficiency of the best linear fluorescent luminaires. The latest Department of Energy (DoE) projections* had estimated that this level of luminaire efficiency would not occur until after 2020, but Cree’s latest innovation has made this possible six years sooner than projected. The prototype leverages Cree’s vertical integration with innovations in LED chips, optics, materials technology and novel system design to deliver unprecedented performance. Read more »

White Paper | Technology | Dec 11, 2013

The Right Choice of Current-Limiting Resistors for Constant Voltage LED Drivers

There are different resistor types for LED lighting available (Img: Riedon Inc) While LEDs are mostly driven by current sources, there are also several applications where constant voltage drivers are used. In that case current limiting resistors are mandatory. But that raises the question which resistor is the right one to guarantee reliable and accurate control while not compromising efficiency. Phil Ebbert, VP of Engineering at Riedon Inc. explains what to take care of and how to determine the correct parameters. Read more »

White Paper | Lighting Applications | Dec 06, 2013

LED Lighting Masters the Art of In-Flight Calm on Airbus A380s and Boeing 787s

A380 Airbus Cabin Aboard a state-of-the-art aircraft might be the last place you would think of yourself enjoying a warm “candlelit” dinner, followed by a good night’s sleep under a starry night sky. The truth is, the latest aircraft cabins seek to provide just that – a revolutionary in-flight experience through the use of mood lighting. Mood lighting uses the full spectrum of colors and the ability to change these colors continuously with LEDs to mimic or enhance a sunrise morning or a bright, fresh afternoon or a cool evening that winds down the day. These lighting effects even seek to reduce your likelihood of jetlag. LED lighting programs can be specifically designed to gradually shift your waking and sleeping biorhythms to match that of your destination city. Read more »

White Paper | Standardization & Regulation | Dec 03, 2013

The Connected Lighting Alliance Extends Scope to Indoor Professional Lighting

The Connected Lighting Alliance aims to define and endorse standards of wireless lighting controls for different applications Following its endorsement of ZigBee Light Link as the preferred common open standard for residential connected lighting applications, The Connected Lighting Alliance announced today the launch of a new initiative focused on the indoor professional lighting market. The Alliance will analyze market requirements for indoor professional lighting applications and identify standard development organizations to engage with. As an open association, the Alliance invites interested companies to join the industry initiative and share their expertise in this field. The contribution of multiple companies in the lighting industry will greatly benefit the global adoption of wireless lighting solutions. Read more »

White Paper | Standardization & Regulation | Dec 03, 2013

The Connected Lighting Alliance Extends Scope to Indoor Professional Lighting

The Connected Lighting Alliance aims to define and endorse standards of wireless lighting controls for different applications Following its endorsement of ZigBee Light Link as the preferred common open standard for residential connected lighting applications, The Connected Lighting Alliance announced today the launch of a new initiative focused on the indoor professional lighting market. The Alliance will analyze market requirements for indoor professional lighting applications and identify standard development organizations to engage with. As an open association, the Alliance invites interested companies to join the industry initiative and share their expertise in this field. The contribution of multiple companies in the lighting industry will greatly benefit the global adoption of wireless lighting solutions. Read more »

White Paper | Standardization & Regulation | Nov 14, 2013

Zhaga Publishes Book 7 and Book 8 Interface Specifications for LED Light Engines

Zhaga Logo Two more interface specifications for LED light engines have been published by the Zhaga Consortium. Zhaga is an international organization that is enabling the interchangeability of LED light sources made by different manufacturers. The interface specifications, designated Book 7 and Book 8, can now be downloaded from the Zhaga website . Read more »

White Paper | Standardization & Regulation | Nov 14, 2013

Zhaga Publishes Book 7 and Book 8 Interface Specifications for LED Light Engines

Zhaga Logo Two more interface specifications for LED light engines have been published by the Zhaga Consortium. Zhaga is an international organization that is enabling the interchangeability of LED light sources made by different manufacturers. The interface specifications, designated Book 7 and Book 8, can now be downloaded from the Zhaga website . Read more »

White Paper | Technology | Nov 04, 2013

UC Santa Barbara: Optimizing Phosphors Using Simple Guidelines Improves Efficiency of Solid-State Lighting

This illustration demonstrates how bright blue LED light, shone through its complementary yellow phosphor, yields white light By determining simple guidelines, researchers at UC Santa Barbara's Solid State Lighting & Energy Center (SSLEC) have made it possible to optimize phosphors –– a key component in white LED lighting –– allowing for brighter, more efficient lights. Read more »

White Paper | IP, Reports & Roadmaps | Oct 28, 2013

DOE Publishes Report on Color Stability of LED Lighting Products

Chromaticity over time for a subset of the lamps. When intermediate points are shown, the color shift appears unpredictable (a). Δu'v' for the best and worst performing lamps (b). Baseline and final (25,000-hour) chromaticity coordinates for each lamp sample (c). Initial and final chromaticity of lamps tested by CALiPER in 2008–2010 (d) The U.S. Department of Energy (DOE) has published a new report, Color Maintenance of LEDs in Laboratory and Field Applications. Although concern for parametric failure of LED lighting products has largely been focused on lumen maintenance, color shift is a cause of early failure for some products, especially in applications where visual appearance is critical. Read more »

White Paper | Technology | Oct 28, 2013

Los Alamos National Laboratory Announces Dramatic Improvements in QD Technology

Postdoctoral researcher Young-Shin Park characterizing emission spectra of LEDs in the Los Alamos National Laboratory optical laboratory. Inset: The quantum dot device structure shown with a transmission electron microscopy (TEM) image of a cross-section of a real device Dramatic advances in the field of quantum dot light emitting diodes (QD-LEDs) could come from recent work by the Nanotechnology and Advanced Spectroscopy team at Los Alamos National Laboratory. Read more »

White Paper | Technology | Oct 23, 2013

Latest LRC Program Aims to Fine Tune Light for Greenhouse Crops & Medicinal Plants

Light and plants expert Tessa Pocock, Ph.D., recently joined the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute as a senior research scientist, leading the development of a new plant physiology lighting program. Her research focuses on plant photosynthesis, and plant development and regulation by light for traditional greenhouse crops and the emerging field of medicinal plants. Read more »

White Paper | Technology | Oct 08, 2013

Two-Switch Flyback Solution for LED Street Lighting

Won-Seok Kang has worked for Fairchild Semiconductor since 2006 and is currently an Industrial Senior Application Engineer for Fairchild’s Switch Mode Power Supply in the Power Conversion Division located in Korea. His research interests are in functional power module, LED drivers, resonant and soft switching dc/dc converters, and electronic ballast. He has a B.S. and M.S. degree in electronics engineering LEDs provide high efficiency and long life compared to conventional lighting sources. Therefore, they are becoming first priority of lamp types to reduce energy consumption for internal or external lighting. This is also the case in street lightings where better efficiency and longer life are essential for less cost. A switching power supply designed to power up LED lamp should also have high efficiency and robustness to assure maintenance free lifetime as long as LED lamp. Resonant converters are one of the most popular power supply topologies here since their performance delivers increased power efficiency. LLC resonant converter has drawn attention thanks to its features such as high power conversion efficiency and low voltage stress on secondary rectifier. However, complicated design and high manufacturing cost of LLC resonant converters have been obstacles to fast time-to-market and cost reduction. Another problem of LLC resonant converter is large circulating current that is required to maintain zero voltage switching (ZVS). It causes relatively high power consumption at light load. LLC resonant converter also has potential failure issue when MOSFET with poor body diode performance is used. Two-switch flyback converter is proposed as an alternative solution to overcome the limitations of the LLC resonant converter. With additional switch on the high side, leakage inductance energy is clamped and recycled back to input to improve efficiency. The dissipative snubber circuit is no longer needed. A 120W rated switching power supply is designed utilizing two-switch flyback topology. The details of design specification and test results are presented. Read more »

White Paper | Technology | Oct 08, 2013

Why Pin Fin LED Coolers Perform Better Under Tilted Position?

For passive cooling, both, simulation and measurement results demonstrate the advanages of a pin fin design over conventional fins when tilted more than 50° For the experiment we compare the ModuLED 9980 with the LPF11180-ZHE. The ModuLED 9980 is a passive LED cooler from extruded aluminium with a diameter. of 99mm and a height of 80 millimeter, thermal resistance under vertical position 1.02°C/W. The LPF11180-ZHE is a passive LED cooler with pin fin structure with a diameter of 111mm and a height of 80mm, thermal resistance under vertical position 1.07°C/W. Read more »

White Paper | IP, Reports & Roadmaps | Sep 12, 2013

New Comprehensive Investigation on LED Phosphors and Down-Converters Patents

Basic phosphor respectively light conversion IP licensing structure Yole Développement announces its new market & technology patent investigation, LED Phosphors and Down-Converters. Hundreds of companies are involved in LED phosphor IP. Most of the major LED players are present in the list of the top patent assignees. But independent phosphor manufacturers are also emerging as major forces in the IP landscape. Read more »

FEATURED

Epoxy Features Very Low Coefficient of Thermal Expansion

Epoxy Features Very Low Coefficient of Thermal Expansion Master Bond EP30LTE-2 has been developed for joining dissimilar substrates exposed to thermally or mechanically induced stresses. It can be used for sealing, coating and encapsulating, especially for small to medium sized castings where a very low coefficient of thermal expansion (CTE) is required. Read more »

FEATURED

New BJB LED Connector for Linear LED Modules: Book 21 Compliant

New BJB LED Connector for Linear LED Modules: Book 21 Compliant Lampholders were standard in older, traditional lighting systems. Modern LED fixtures that utilize non-replaceable LEDs create several assembly and field-replacement disadvantages. Zhaga Book 21 addresses these shortcomings by standardizing linear 'socketable' LED modules. In accordance with Book ... Read more »

FEATURED

EzyLED™ Now Stocked at Digi-Key

EzyLED™ Now Stocked at Digi-Key American Bright, a global LED lighting solutions manufacturer, announced a series of EzyLED 3030. American Bright's EzyLED™ is a proprietary LED device with a built-in IC. This patented design drastically reduces the need for additional circuitry and other on-board components making it the ideal ... Read more »

FEATURED

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

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 »

FEATURED

Measuring the Oxygen Content of Blood with LEDs

Measuring the Oxygen Content of Blood with LEDs Pulse oximetry is a non-invasive method for determining haemoglobin (Hb) saturation through oxygen in the blood and heart frequency. It uses the fact that oxygen-rich and oxygen-poor haemoglobin absorb red and infrared light differently. In order to measure the oxygen content reliably, LEDs with ... Read more »

EDITORIAL

The 2019 LpS & TiL Award Winners: Celebrating the Complete Spectrum of Light

The 2019 LpS & TiL Award Winners: Celebrating the Complete Spectrum of Light It is a great pleasure for the LpS and TiL organization committee to announce the award winners for 2019. For the second time in a row, after the traditional cruise on the lake from Bregenz to Lindau, the gala dinner at the Eilgut Halle has proven to being a great place for the LpS & TiL award ... Read more »

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