Tag Archives: letter-leds-tech

DuPont Displays today announced the opening of a state-of-the-art, scale-up manufacturing facility designed to deliver production scale quantities of advanced materials that enable large-format, solution-based printed Organic Light Emitting Diode (OLED) displays. These materials are designed to help manufacturers develop OLED displays that are brighter, more vivid, longer lasting and significantly less expensive than the OLED TVs on the market today. The facility is located at the DuPont Stine-Haskell Research Center (Stine-Haskell) in Newark, Del., near DuPont’s global headquarters in Wilmington.

“Materials are critical to the performance of an OLED TV and we are confident that DuPont has the best performing solution OLED materials available in the market today,” said Avi Avula, global business director, DuPont Displays. “Our vision is that OLEDs will become the display standard and to make that vision a reality, we are focused on helping our customers bring the cost of large sized OLED TVs down to less than $1000 by 2020.”

DuPont’s new scale-up facility is sized to meet the future growth expectations of the OLED TV industry, which analysts predict will increase by over 70 percent for the next several years and will require large quantities of highly sophisticated OLED materials. DuPont has been developing its suite of advanced OLED materials for the last 15 years. These materials are highly regarded for both solution and evaporative applications due to their long lifetime and deep color. In addition to its recently announced collaboration with an inkjet equipment maker to advance solution printed displays, DuPont is actively engaged with the leading OLED display manufacturers to bring solution printed OLED technology to market as quickly as possible.

DuPont’s new OLED facility at Stine-Haskell has large-scale formulation systems and can support simultaneous production of multiple product lines. It was designed with a focus on employee safety, environmental responsibility and producing superior quality materials with the highest possible purity. The project was partially funded by a grant from the state of Delaware in 2012, with DuPont investing more than $20 million in the facility.

DuPont Displays brings more than 15 years of experience in enabling evaporative and solution-based OLED technologies through advanced materials that deliver the color, efficiency and lifetime performance that display manufacturers and consumers demand. DuPont offers highly engineered, next-generation OLED materials as well as solution process know-how that makes the promise of lower cost OLED technology commercially feasible for TVs and other large-format displays.

A screen-printable functionalized graphene ink supplied by Goodfellow performs better than normal carbon-based ink, opening the door to innovative applications that require exceptional electrical conductivity, excellent ink coverage, and high print resolution. Such applications are found in light flexible displays, plastic electronics, printed circuit boards, thin film photovoltaics, sensors, electrodes, and OLEDs.

The ink is made with HDPlas (R) functionalized graphene nanoplatelets and is optimized for the viscosity and solid contents required of semi-automatic and manual screen-printing equipment. Substrates that can be printed include but are not limited to polymers, ceramics, and papers.

In addition to the distinguishing characteristics stated above, functionalized graphene ink is:

  • Flexible on appropriate substrates
  • Metal-free, 100% organic (non-tarnishing)
  • Curable at low temperatures
  • Environmentally friendly

The ink is fully customizable and can be modified for specific applications. Scientists and printers running trials with the small quantities available from Goodfellow (100g to 1000g) can, if desired, consult with Goodfellow to further tailor performance in order to meet individual needs.

As a response to meet the increasing demands (higher heat/brightness characteristics) of cutting-edge LED technologies, Shin-Etsu Silicones of America (SESA), a U.S. subsidiary of Shin-Etsu Chemical Co. Ltd. of Japan, has recently introduced its new optically clear LIMS (Liquid Injection Molding System) X-34-1972-3 material.

With a transparency of 95%, the new material is ideal for expanding LED applications in street lighting, automotive, and exterior illumination. Notably, its high temperature resistance, compared to thermoplastic resins, allows molded silicone optics to be positioned in close proximity to the LED light source without yellowing or cracking over extended operating life spans.

According to SESA’s North America Marketing Manager, Eric Bishop, “Next-generation HBLED systems are getting hotter as light output continues to increase. The advanced engineering properties of our X-34-1972-3 material delivers unparalleled heat resistance and clarity at these higher operating temperatures.”

Bishop also noted that the material has been tested in-house and at customers with promising results.

The optically clear LIMS X-34-1972-3 material will be on display during SESA’s open-house demonstration at their LIMSTM Technical Center in Akron, Ohio on Monday, October 12 (1:00 pm – 5:00 pm). The informal event will feature the production of 100% silicones magnifying lenses and the opportunity to network with industry suppliers and associates.

X-34-1972-3 properties:

  • Viscosity (A/B): 450/450 Pa.s
  • Hardness: 70 A
  • Tensile Strength: 7.5 MPa
  • Tear Strength: 12kN/m
  • Refractive Index: 1.41
  • Transparency: 95%

Researchers at Aalto University and VTT Technical Research Centre of Finland have succeeded in developing a method which helps to improve the relative uncertainty in measuring the luminous efficacy of LEDs from the approximate five percent of today to one per cent in the future. The results were just published in the Light: Science & Applications journal.

Thus far, solutions based on incandescent lamps have been used in photometry, i.e. in measuring light detected by the human eye, explains Tomi Pulli, a doctoral student at Aalto University.

“The photometers that lamp manufacturers use for calibrating their devices have been produced and calibrated for incandescent lamps, which results in errors when measuring the efficacy of LEDs. In our research, we used a LED lamp with a well-defined spectrum and a PQED detector, which we developed together with VTT MIKES Metrology and European partners, and whose spectral responsivity can be determined highly accurately. Therefore, there was no need for the problematic optical filters used in applications based on incandescent lamps. Indeed, accurately determining and analyzing the spectrum of the LED was the most challenging and crucial part of the research,” he revealed.

The detector used in measurements by Pulli and his co-researchers measures the illuminance of LEDs in a very small area. According to Professor Erkki Ikonen, the head of research, the next step will be to move onto measurements corresponding to real-life conditions for lighting.

“LED lamps emit light to all directions. In order to measure the luminous efficacy, we thus use a device called an integrated sphere, which takes into account light coming from different directions,” he specifies, and reminds that the history of LEDs is still short when compared to incandescent and fluorescent lamps. Therefore, there is still little information available on their actual efficacy and aging properties. Indeed, it is essential to determine luminous efficacy as accurately as possible so that such lamps can be introduced in the market that transform as much electrical energy into light useful to the human eye as possible.

So far, the portion of LEDs has been around 10 percent globally, but the amount is increasing at a rapid pace, Ikonen explains. Lighting amounts to approximately 20 percent of the electricity consumption in the world. Once the share of LEDs increases close to 50 percent, an improvement of as little as one percent in the accuracy of measuring the luminous efficacy of the lamps introduced in the market will mean saving billions of euros each year.

Until now, transparent electrode materials for OLEDs have mainly consisted of indium tin oxide (ITO), which is expected to become economically challenging for the industry due to the shrinking abundance of indium. Therefore, scientists are intensively looking for alternatives. One promising candidate is graphene, whose application fields are more closely investigated in the project GLADIATOR (“Graphene Layers: Production, Characterization and Integration”).

The project GLADIATOR, which is funded by the European Commission, has reached its midterm and has already achieved some successes. The aim of the project is the cost-effective production of high quality graphene at large area, which can then be used for numerous electrode applications. The usability of such applications will be demonstrated at the Fraunhofer FEP by integrating this graphene in OLEDs.

With graphene as an electrode, the researchers at the Fraunhofer FEP hope for flexible devices with higher stability. Beatrice Beyer, project coordinator, says: “Graphene is a very interesting material with many possibilities. Because of its opto-electrical properties and its excellent mechanical stability, we expect that the reliability of flexible electronics will be improved many times over.”

Graphene is a rediscovered modification of carbon with two-dimensional structure, which has gained enormously in popularity since its successful isolation in 2004. Such so-called “monolayer” graphene is synthesized on a metal catalyst via a chemical vapor deposition (CVD) process and transferred by a further process step to a target substrate, such as thin glass or plastic film. Here, it is very important that no defects are added which might reduce the quality of the electrode. In order to compete with the reference material ITO, the transparency and conductivity of graphene must be very high. Therefore, not only is the process of electrode manufacturing being optimized, but also different ways of doping graphene to improve its properties are being examined.

At the same time, the developed process steps must be easily scalable for later industrial use. These many challenges are faced by a project consortium consisting of 16 partners from six EU member states and Switzerland.

The Fraunhofer FEP is coordinating the GLADIATOR project and acts as an end-user of the graphene electrode. Scientists examine the integration of graphene and compare it to the reference material ITO. The sophisticated material properties of graphene must be maintained during the integration in organic devices. To this end, several methods for cleaning and structuring the graphene must be modified. In addition, the processes for different target substrates such as glass or flexible foil must be adapted and optimized. The first hurdles have been overcome thanks to a close cooperation between the consortium partners and the first defect-free OLEDs on transparent graphene electrodes have been realized on small areas. The target of the next one and a half years is to successfully illuminate large area OLEDs.

The GLADIATOR project will run until April 2017. By this time several types of OLED will have been made using graphene electrodes: a white OLED with an area of about 42 cm2 to demonstrate the high conductivity, and a fully-flexible, transparent OLED with an area of 3 cm2 to confirm the mechanical reliability.

With the help of a semiconductor quantum dot, physicists at the University of Basel have developed a new type of light source that emits single photons. For the first time, the researchers have managed to create a stream of identical photons. They have reported their findings in the scientific journal Nature Communications together with colleagues from the University of Bochum.

A single-photon source never emits two or more photons at the same time. Single photons are important in the field of quantum information technology where, for example, they are used in quantum computers. Alongside the brightness and robustness of the light source, the indistinguishability of the photons is especially crucial. In particular, this means that all photons must be the same color. Creating such a source of identical single photons has proven very difficult in the past.

However, quantum dots made of semiconductor materials are offering new hope. A quantum dot is a collection of a few hundred thousand atoms that can form itself into a semiconductor under certain conditions. Single electrons can be captured in these quantum dots and locked into a very small area. An individual photon is emitted when an engineered quantum state collapses.

Noise in the semiconductor

A team of scientists led by Dr. Andreas Kuhlmann and Prof. Richard J. Warburton from the University of Basel have already shown in past publications that the indistinguishability of the photons is reduced by the fluctuating nuclear spin of the quantum dot atoms. For the first time ever, the scientists have managed to control the nuclear spin to such an extent that even photons sent out at very large intervals are the same color.

Quantum cryptography and quantum communication are two potential areas of application for single-photon sources. These technologies could make it possible to perform calculations that are far beyond the capabilities of today’s computers.

Researchers from Holst Centre (set up by TNO and imec), imec and CMST, imec’s associated lab at Ghent University, have demonstrated the world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles. This paves the way to wearable displays in clothing providing users with feedback.

Wearable devices such as healthcare monitors and activity trackers are now a part of everyday life for many people. Today’s wearables are separate devices that users must remember to wear. The next step forward will be to integrate these devices into our clothing. Doing so will make wearable devices less obtrusive and more comfortable, encouraging people to use them more regularly and, hence, increasing the quality of data collected. A key step towards realizing wearable devices in clothing is creating displays that can be integrated into textiles to allow interaction with the wearer.

“Wearable devices allow people to monitor their fitness and health so they can live full and active lives for longer. But to maximize the benefits wearables can offer, they need to be able to provide feedback on what users are doing as well as measuring it. By combining imec’s patented stretch technology with our expertise in active-matrix backplanes and integrating electronics into fabrics, we’ve taken a giant step towards that possibility,” says Edsger Smits, Senior research scientist at Holst Centre.

The conformable display is very thin and mechanically stretchable. A fine-grain version of the proven meander interconnect technology was developed by the CMST lab at Ghent University and Holst Centre to link standard (rigid) LEDs into a flexible and stretchable display. The LED displays are fabricated on a polyimide substrate and encapsulated in rubber, allowing the displays to be laminated in to textiles that can be washed. Importantly, the technology uses fabrication steps that are known to the manufacturing industry, enabling rapid industrialization.

Following an initial demonstration at the Society for Information Display’s Display Week in San Jose, USA earlier this year, Holst Centre has presented the next generation of the display at the International Meeting on Information Display (IMID) in Daegu, Korea, 18-21 August 2015. Smaller LEDs are now mounted on an amorphous indium-gallium-zinc oxide (a-IGZO) TFT backplane that employs a two-transistor and one capacitor (2T-1C) pixel engine to drive the LEDs. These second-generation displays offer higher pitch and increased, average brightness. The presentation will feature a 32×32 pixel demonstrator with a resolution of 13 pixels per inch (ppi) and average brightness above 200 candelas per square meter (cd/m2). Work is ongoing to further industrialize this technology.

The world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles developed by Holst Centre, imec and CSMT.

The world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles developed by Holst Centre, imec and CSMT.

A coalition of leaders from the tech industry and academia, led by the Semiconductor Industry Association (SIA) and Semiconductor Research Corporation (SRC), today released a report highlighting the urgent need for robust investments in research to advance the burgeoning Internet of Things (IoT) and develop other cutting-edge innovations that will sustain and strengthen America’s global technology leadership into the future. The report, titled “Rebooting the IT Revolution: A Call to Action,” calls for a large-scale, public-private research initiative called the National Computing and Insight Technologies Ecosystem (N-CITE).

“The United States stands at a crossroads in the global race to uncover the next transformative innovations that will determine technology leadership,” said John Neuffer, president and CEO of the Semiconductor Industry Association, which represents U.S. leadership in semiconductor manufacturing, design, and research. “We either aggressively invest in research to foster new, semiconductor-driven technologies such as the Internet of Things that will shape the future of the digital economy, or we risk ceding ground to competitors abroad. The findings and recommendations in the Rebooting the IT Revolution report will help the United States rise to this bold challenge, choose the right path forward, and harness the new technologies that will keep America at the tip of the spear of innovation.”

Basic scientific research funded through agencies such as the National Science Foundation (NSF), the National Institute of Standards and Technology (NIST), the Defense Advanced Research Projects Agency (DARPA), and the Department of Energy (DOE) Office of Science has yielded tremendous dividends, helping launch technologies that underpin America’s economic strength and global competiveness. The U.S. semiconductor industry has been a reliable partner in funding research, investing about one-fifth of revenues each year in R&D – the highest share of any industry.

“The IoT — from ubiquitous sensor nodes to the cloud — will be orders of magnitude larger and more complex than anything we know today. Moreover, as the demand for more energy-efficient yet more powerful computing grows, new approaches such as brain-inspired computing have the potential to transform the way systems are designed and manufactured,” said Ken Hansen, president of Semiconductor Research Corporation (SRC), the world’s leading university research consortium for semiconductor technologies. “Addressing the fundamental research challenges outlined in this report is essential to creating the infrastructure that will enable the conversion of data to insight and actionable information with appropriate security and privacy. While some areas are moving forward quickly, others require collaborative research among industry, academia and government to capture the untold benefits of this distributed, intelligent ecosystem.”

The report contains opinions from industry, academic and government leaders who participated in the Rebooting the IT Revolution Workshop on March 30–31, 2015. The workshop was sponsored by SIA and SRC and supported by NSF.

Participants stressed the need for fundamental research in the following areas in order to fully realize IoT breakthroughs and sustain America’s technology leadership: energy-efficient sensing and computing, data storage, real-time communication ecosystem, multi-level and scalable security, a new fabrication paradigm, and insight computing. Many of these areas align with Federal research initiatives, including the National Strategic Computing Initiative, the BRAIN Initiative, and the National Nanotechnology Initiative Grand Challenges.

“IoT technology will connect directly to both the physical and social worlds by advancing disruptive hardware, cross-field networking, insight-generating IT, and principles of convergence, which are at the core of future U.S. technology and economic development,” said Mihail C. Roco, Senior Advisor for Science and Engineering at NSF and a key architect of the National Nanotechnology Initiative. “The report’s contents reflect a new way of thinking to create an interdependent, scientific-technological-social ecosystem driven by the emergent confluence of IT with nanotechnology, advanced manufacturing, cognitive sciences, sustainability, and safety. All are in response to an increasingly interconnected, knowledge-driven and demanding society. In the longer term, implementation of the report would support global human progress.”

SUSS MicroTec, a global supplier of equipment and process solutions for the semiconductor industry and related markets, and the Singh Center for Nanotechnology at the University of Pennsylvania (Penn) are announcing a cooperation agreement in the field of nanoimprint technologies. As part of this cooperation, Penn has recently received the equipment set and the technology know-how for Substrate Conformal Imprint Lithography (SCIL), that will expand the capabilities of the recently installed MA/BA6 Gen3 Mask Aligner from SUSS MicroTec at Penn.

Substrate Conformal Imprint Lithography (SCIL) is a nanoimprint technique combining the advantages of both soft and rigid stamps, allowing large-area patterning and sub-50nm resolution to be achieved at the same time. SCIL is applied in diverse fields, ranging from HB LEDs, Photovoltaics, MEMS, NEMS and mass production of optical gratings for gas sensing and telecommunications.

The Singh Center for Nanotechnology will implement SCIL for use in plasmonic devices, semiconductor nanowires, flexible nanocrystal electronics, biodegradable sensors and MEMS batteries.  In addition, Lithography Manager Dr. Gerald Lopez will lead the Center’s efforts in qualifying new nanoimprint materials and related process technology development in close cooperation with SUSS MicroTec.

As a further important part of the cooperation, SUSS MicroTec`s customers will gain direct access to the cleanroom facilities and the equipment set installed at Penn, serving as a demonstration center for North American customers. The experience and high technology level of Penn allows the customer to see the entire process flow, the imprinting process itself and the subsequent steps up to a finished device.

“We are pleased to collaborate with SUSS MicroTec for developing applications with SCIL. By combining our strengths in micro- and nanofabrication, we are able to provide superior nanoimprint capabilities to our researchers,” stated Professor Mark Allen, Scientific Director of the Singh Center for Nanotechnology and Alfred Fitler Moore, Professor of Electrical and Systems Engineering. “This industrial partnership enhances our ability to demonstrate how nanoimprint technology serves as a catalyst in research and its translation into the commercial sector.”

“We are very happy about the cooperation with the Singh Center for Nanotechnology. Their work will contribute strongly to further commercialize this large area nano-patterning technique in order to accelerate the adoption for volume production. In addition, our customers do not just benefit from the possibility to use Penn’s facilities and get insights to the entire imprinting process, but also from Penn´s knowledge, by having an experienced partner at hand”, says Ralph Zoberbier, General Manager Exposure and Laser Processing of SUSS MicroTec.“

Pixelligent Technologies, a manufacturer of high index materials for demanding optoelectronics applications, announces the addition of four new OLED lighting products to its PixClear Zirconia nanocrystal family. These new products will deliver light extraction and efficiency for a wide variety of OLED lighting applications.

“Our new family of high index products for OLED lighting expands upon Pixelligent’s leadership position in the solid state lighting market, and we believe it will help accelerate the adoption of OLED lighting,” said Craig Bandes, President and CEO of Pixelligent.

The new PixClear for OLED products can be incorporated into OLED lighting panels as an internal light extraction and smoothing layer, delivering more than twice the amount of light currently extracted in OLED lighting devices. The product line includes two solvent-based and two formulated materials, available both as samples and at commercial scale.

“The OLED lighting market is ripe for accelerated growth and broad-user adoption and Pixelligent is delivering the functionality required to help OLED lighting manufacturers deliver substantially more lumens-per-watt,” added Bandes.