LEDs & OLEDs

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 »

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 »

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 »

Laser Technology for Lighting Applications: A Review and Analysis of a Promising Technology

LpR 68 Article, page 44: LEDs are currently the dominating light source: efficient and cost effective. But LEDs also have some drawbacks. Another interesting technology developed slowly in the shadow of LEDs and has become an interesting solution for some specific applications: GaN based blue solid state laser devices. Although this technology offers some very interesting advantages, it also has challenges. Nicola Trivellin, Matteo Buffolo, Carlo De Santi, Gaudenzio Meneghesso, Enrico Zanoni and Matteo Meneghini from the University of Padova and its spin-off LightCube have been working toward the development of experimental systems and demonstrators and disclose their findings of the comparison between LED and LD systems. 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 »

Electron Beam Patterning for Full-Color HR OLED Displays

OLED microdisplays are increasingly establishing themselves in consumer-ready wearables and data glasses. In order to meet the requirements for higher efficiency, higher contrast, and higher resolutions in these applications, Fraunhofer FEP scientists have developed a new micropatterning approach for OLEDs on silicon substrates. This might eliminate the use of color filters and shadow masks in the future and allow full-color displays to be developed by means of a new process. An increase in efficiency and considerably broader color gamut have already been demonstrated in first experiments. Read more »

Electrical Over Stress - How to Prevent an LED Failing Earlier than Expected

Article from LpR 66, page 70: While LEDS are, in general, very robust, failures still happen due to electrical over stress. Mauro Ceresa, EMEA Field Application Engineer Manager at Cree, will cover all aspects related to electrical over stress, or when an LED fails due to being subjected to a voltage beyond its specification limits. He will explain why the failure occurs and how to prevent this from happening. The article will explain the fundamental aspects of a good PCB layout design and how this is linked to the longevity of an LED. Read more »

Liquid-Suspended White QD LEDs Achieve Luminous Efficacy Record

Quantum dot (QD) white LEDs that show a luminous efficacy of 105 lm/W have been developed. The QDs are liquid-based and, according to researchers, could help the LEDs achieve an efficacy double that of LEDs that incorporate quantum dots in solid films. With further development, researchers say the new LEDs could reach an efficacy over 200 lm/W. Read more »

Technologies | Research Reports | LEDs | Manufacturing | Jul 12, 2018

InteGreat Project Successfully Researched New Approaches to LED Production

In the InteGreat research project, Osram Opto Semiconductors coordinated a consortium comprising seven partners from science and industry. Between December 2014 and February 2018 the project partners investigated time-honored manufacturing approaches and know-how along the entire LED production process with the aim of identifying potential areas for optimization. The new insights allow for LED products to be given additional superior properties that would have been difficult or even impossible to achieve with the technologies previously used to produce LEDs. Read more »

A Near Infrared Enhanced LED Lighting Approach

With the evolution of LED lighting, one topic has come more and more in the focus of the lighting industry: Human Centric Lighting (HCL). While HCL is not clearly defined, a common understanding is that this is light and lighting that supports health and the well-being of humans. Some new proposals are going beyond the approach of providing just visible light in adequate quality, but also to providing invisible radiation, UV and/or NIR that support health and well-being. Some research and the evolution of humans show clear evidence for positive effects of this kind of illumination. Scott Zimmerman, CEO at Silas, presents a new approach that adds NIR radiation to LED illumination. He explains the background of this idea, how it also improves the quality of visible light and discusses the health benefits. Read more »

Full-Color InGaN/AlGaN Nanowire Light-Emitting Diodes for SSL and Displays

III-nitride based nanowire light-emitting diodes (LEDs) have received a staggering response as a future candidate for solid-state lighting and full-color displays due to their unique and exceptional features including drastically reduced polarization fields, dislocation densities as well as the associated quantum confined Stark effect (QCSE) on account of their effective strain relaxation. Moab Rajan Philip and his supervisor Dr. Hieu P Nguyen in the Nano-Optoelectronic Materials and Devices Laboratory at the New Jersey Institute of Technology (NJIT) present astonishing ideas to fabricate and control the color emission of III-nitride nanowire LEDs via molecular beam epitaxy (MBE) growth techniques. The advantage of such LEDs and their characteristics is also discussed. Read more »

KAIST Team Develops Flexible Blue Vertical Micro LEDs

In CES 2018, micro LED TV was spotlighted as a strong candidate for replacing the active-matrix organic light-emitting diode (AMOLED) display. Micro LED is a sub-100 um light source for red, green and blue light, which has advantages of outstanding optical output, ultra-low power consumption, fast response speed, and excellent flexibility. Professor Keon Jae Lee from the Department of Materials Science and Engineering and his team have developed a low cost production technology for thin-film blue flexible vertical micro LEDs (f-VLEDs). Read more »

Smart Printing: Fraunhofer IAP Develops Power Generating Films and Luminescent Glass

New inks for inkjet printers make it possible to print organic displays or solar cells on film and glass for the use in architecture, the textile industry and many other industries. Read more »

Technologies | Light Generation | LEDs | Color LEDs | Mar 29, 2018

Scientists Reveal the Fundamental Limitation of In Concentration in InGaN Solid-State Devices

For the first time an international research group has revealed the core mechanism that limits the indium (In) content in indium gallium nitride ((In, Ga)N) thin films - the key material for blue light emitting diodes (LED). Increasing the In content in InGaN quantum wells is the common approach to shift the emission of III-Nitride based LEDs towards the green and, in particular, red part of the optical spectrum, necessary for the modern RGB devices. The new findings answer the long-standing research question: why does this classical approach fail, when we try to obtain efficient InGaN-based green and red LEDs? Read more »

Technologies | Light Conversion | LEDs | Quantum Dots | Feb 26, 2018

Realizing Highly Efficient QD LEDs with Metallic Nanostructures at Low Cost

The Korea Advanced Institute of Science and Technology (KAIST) announced that a team of their researchers have discovered a technology that enhances the efficiency of Quantum Dot LEDs. Professor Yong-Hoon Cho from the Department of Physics and his team succeeded in improving the efficiency of Quantum Dot (QD) Light-Emitting Diodes (LEDs) by designing metallic nanostructure substrates. Read more »

Technologies | Light Generation | Phosphors | Feb 22, 2018

Supercomputers Aid Discovery of New, Inexpensive Material to Make LEDs with Excellent Color Quality

A team led by engineers at the University of California San Diego has used data mining and computational tools to discover a new phosphor material for white LEDs that is inexpensive and easy to make. Researchers built prototype white LED light bulbs using the new phosphor. The prototypes exhibited better color quality than many commercial LEDs currently on the market. Read more »

Resources | IP Snapshot | LEDs | Nanowire | Feb 01, 2018

IP Snapshot: "Nanowired LEDs"

Abstract from the most cited patent (US20030168964A1, Solidlite Corp.) A nanowire light emitting device and display includes a cover substrate , and a transparent conductive substrate mounted on the transparent conductive film and having a surface plated with a metal layer, a nanowire light emitting member mounted on the transparent conductive substrate and having multiple nanowire light emitting diodes each having a structure of P-type, N-type and light emitting layer, and an insulation layer support post mounted between the transparent conductive substrate and the cover substrate for supporting the transparent conductive substrate and the cover substrate. Read more »

Resources | Tech-Talks Bregenz | Research | Light Generation | Jan 15, 2018

Tech-Talks BREGENZ - Julia Frohleiks, Researcher, University of Duisburg-Essen

In his commentary on technical progress and innovation, Dr. Sejkora said: “In the early stage, in the first phase of its life cycle, technology is mainly driven by fundamental research.” He went on to say that we can never predict how a technology will develop. Researchers from the University of Duisburg-Essen, working in the Nano Energy Technical Center (NETZ), worked on this type of fundamental technology and their submission received the LpS 2017 Scientific Award. Ms. Julia Frohleiks, a Ph.D. student, was a major contributor to this research in the group led by Dr. Ekaterina Nannen and accepted the award in Dr. Nannen’s name. In the following interview she gives some background information and discloses future research possibilities. Read more »

Technologies | LEDs | Light Generation | Dec 13, 2017

Atomistic Calculations Predict that Boron Incorporation Increases the Efficiency of LEDs

High-power white LEDs face the same problem that Michigan Stadium faces on game day -- too many people in too small of a space. Of course, there are no people inside of an LED. But there are many electrons that need to avoid each other and minimize their collisions to keep the LED efficiency high. Using predictive atomistic calculations and high-performance supercomputers at the NERSC computing facility, researchers Logan Williams and Emmanouil Kioupakis at the University of Michigan found that incorporating the element boron into the widely used InGaN (indium-gallium nitride) material can keep electrons from becoming too crowded in LEDs, making the material more efficient at producing light. Read more »

Phosphors & QDs LED Downconverters Report for Lighting & Displays from Yole Développement

“Volume saturation, price pressure and a shifting intellectual property landscape are forcing the LED phosphor & QDs industry into a rationalization phase,” announces Dr. Eric Virey, Senior Technology & Market Analyst, Yole Développement (Yole). Read more »

A New Technology Is Changing the Tunable White Solutions

Tunable white LEDs are one key element of human centric lighting. Until today, different solutions are currently available but none of them is easy to apply or cost effective enough to speed up the diffusion of human centric lights in building projects. A new approach for tunable white solutions is able to provide flexible lighting for multiple occasions without sacrificing output or going over project budget. Phil Lee, Senior Lighting Engineer from Meteor Lighting will compare this new technology, called ColorFlip™, to conventional tunable white solutions, and talk about current tunable white issues. Read more »

Resources | LpR Article | Research | Light Generation | Oct 31, 2017

Hybrid Quantum Dot Light Emitting Electrochemical Cells

Several new light generation technologies that are overshadowed by LEDs and OLEDs are investigated. Most of these technologies are in a very early stage of research. One such technology, the LEC technology, was presented at LpS 2017. Light emitting electrochemical cells can be compared to OLEDs, but they are based on a much simpler inorganic architecture. The innovation in the presented approach lies in the combination with quantum dots, resulting in a hybrid solution. This novel attempt with all its consequences and future prospects was the reason that the LpS Scientific Award jury voted to bestow the award on Dr. Ekaterina Nannen, Group Leader of the Research Group „Solid State Lighting“ at the Nano-Energie-Technik- Zentrum (NETZ) of the University Duisburg-Essen and her research team, Julia Frohleiks and Svenja Wepfer. Read more »

Technologies | LEDs | Light Generation | Automotive | Oct 02, 2017

Eviyos LED Prototype Revolutionizes Smart Headlights

The Eviyos prototype developed by Osram Opto Semiconductors is the world’s first hybrid LED and represents major progress toward the first market-ready smart controllable high-resolution LED. As soon as oncoming traffic is detected the appropriate pixels are automatically switched off so drivers of oncoming vehicles are not dazzled. The prototype, integrated in a demonstrator from Osram Specialty Lighting, were on show for the first time at ISAL from September 25 through 27, 2017 in Darmstadt. Read more »

Technologies | OLEDs | Flexible OLEDs | Sep 21, 2017

OLEDs Applied to Paper-Thin Stainless Steel

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of R&D in the field of organic electronics, will be presenting OLEDs on gauzy stainless steel foil during aimcal 2017 in Tampa/USA, from October 15-18, 2017. The novel application on display in Booth 22 was developed in cooperation with the Nippon Steel & Sumikin Materials Co., Ltd. (NSMAT) and Nippon Steel & Sumitomo Metal Corporation (NSSMC). Read more »

Technologies | LEDs | Light Generation | Sep 15, 2017

Tracing the Light Inside an LED

The performance of white LEDs can be improved, based on better knowledge of the absorption and scattering of light inside the LED. A new method, developed by the University of Twente in The Netherlands and Philips Lighting, can lead to efficiency improvement and powerful design tools. Read more »

Technologies | LEDs | Light Generation | Sep 15, 2017

Nanoparticles Could Spur Better LEDs, Invisibility Cloaks

In an advance that could boost the efficiency of LED lighting by 50 percent and even pave the way for invisibility cloaking devices, a team of University of Michigan researchers has developed a new technique that peppers metallic nanoparticles into semiconductors. Read more »

Light Generation | Technologies | OLEDs | Flexible OLEDs | Sep 12, 2017

Flexible OLEDs with Adjustable Colors – New Design Options for Lighting Designers

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, one of the leading R&D partners for surface technologies and organic electronics, specializes in the development and fabrication of OLED modules with unconventional properties for specific client designs. The Institute will debut flexible adjustable-color organic light-emitting diodes (OLEDs) at ISAL 2017 in Darmstadt, Germany from September 25-27, 2017 at its booth (No. 31). Read more »

Quantum Dot Based White LEDs for General Illumination

Colloidal quantum dot based white LEDs can be integrated into commercial products meeting the stringent reliability requirements for general illumination and providing LED efficiency gains of 5% to 15% over commercial phosphor based LEDs at CCT’s ranging from 5000 K to 2700 K. Unlike earlier demonstrations, the QD material is applied in an on-chip configuration resulting in drop-in fit, form, and function compatibility to existing LED based luminaires and lamps. Ken T. Shimizu, Director, Novel Technologies and Devices, Research and Development, M. Böhmer, D. Estrada, S. Gangwal, S. Grabowski, H. Bechtel, E. Kang, K. J. Vampola, D. Chamberlin, O. B. Shchekin, and J. Bhardwaj from Lumileds showcase the advantages of on-chip QD LEDs: A commercial lamp at 3000K color temperature and 90 CRI is substituted with QD based LEDs resulting in a system level efficiency gain up to 17%, attributed to the reduced blue LED droop from the lower drive current and the lower heat sink temperature when compared to the standard phosphor based LED lamp output. Read more »