Category Archives: LED Manufacturing

Researchers from the University of Alabama in Huntsville and the University of Oklahoma have found a new way to control the properties of quantum dots, those tiny chunks of semiconductor material that glow different colors depending on their size. Quantum dots, which are so small they start to exhibit atom-like quantum properties, have a wide range of potential applications, from sensors, light-emitting diodes, and solar cells, to fluorescent tags for biomedical imaging and qubits in quantum computing.

This image shows the experimental set-up researchers used to analyze the behavior of quantum dots placed on metal oxides. A laser illuminated the quantum dots to make them glow and a spectrometer was used to analyze the light they emitted. Credit: Seyed Sadeghi/ University of Alabama, Huntsville

This image shows the experimental set-up researchers used to analyze the behavior of quantum dots placed on metal oxides. A laser illuminated the quantum dots to make them glow and a spectrometer was used to analyze the light they emitted. Credit: Seyed Sadeghi/ University of Alabama, Huntsville

A key property of quantum dots that makes them so useful is their fluorescence. Scientists can “tune” quantum dots to emit a specific color of light by adjusting their size — small dots glow blue and large dots glow red. However, the dots’ ability to glow can change over time with exposure to light and air.

Seyed Sadeghi, a physicist at the University of Alabama in Huntsville, wondered if it would be possible to better control how quantum dots react to their environment. His team had previously found that placing quantum dots of a certain type on nanometer-thin layers of chromium and aluminum oxides significantly altered the dots’ behavior: the aluminum oxide increased their emission efficiency, while the chromium oxide increased the dots’ degradation rate when exposed to air. The researchers decided to extend their investigations to quantum dots with different structures.

Quantum dots come in a variety of shapes, sizes, and materials. For Sadeghi and his colleagues’ most recent studies, published in the Journal of Applied Physics, from AIP Publishing, the researchers probed the behavior of four different types of commercially available quantum dots. Some of the quantum dots had protective shells, while others did not. Additionally, some of the dots had cores made of binary materials (two types of semiconductors), while others had ternary material cores (three types of semiconductors). All of the quantum dots had been manufactured by chemical synthesis.

The researchers found that ultrathin aluminum oxide could make quantum dots glow brighter and that the effect was much more significant for quantum dots without protective shells. They also found that while quantum dots with both binary and ternary cores shrink after reacting with the oxygen in air, ternary core dots placed on aluminum oxide glowed brighter despite the shrinkage. This observation surprised the researchers, Sadeghi said, and while they don’t yet have an explanation for the difference, they are continuing to study it.

“The results of these studies can serve to enhance emission efficiency of quantum dots, which is an important feature for many applications such as light emitting devices, sensors, detectors, photovoltaic devices, and the investigation of a wide range of quantum and nano-scale physical phenomena,” Sadeghi said. Quantum dots have already helped increase the efficiencies of many optical devices, he noted, and the further development and application of quantum dots’ unique properties, including in the fields of biological imaging and medicine, continues to be a prime focus of scientific study. As a next step in their own research, Sadeghi and his colleagues plan to investigate how metal oxides might affect the behavior of quantum dots when they are close to metallic nanoparticles.

Soraa, a developer of GaN on GaN LED technology, announced today new psychophysical research proving that whiteness and color rendering have a strong effect on the perception of energy-efficient LED lighting. The study was approved by an Institutional Review Board and led by Kevin Houser at Penn State University.

Compared with conventional blue-based LEDs, study participants overwhelmingly preferred the whiteness and color rendering of Soraa’s full visible spectrum lamps with Violet-Emission 3-Phosphor (VP3) technology. Like conventional electric light sources such as incandescent and halogen lamps, Soraa’s lamps emit full visible spectrum light which renders warm, saturated colors—including important colors like reds and bright greens. Furthermore, these lamps excite Optical Brightening Agents (OBAs) in white objects like clothing, paper and plastics, making them look intentionally whiter. However, in their race to create maximally efficient, cheap products, most LED manufacturers skipped parts of the spectrum. This has resulted in blue-LED based lighting products that cannot truly render whiteness or colors.

Uniquely, Soraa’s full visible spectrum lamps with VP3 Natural White are engineered to emit all colors of the rainbow, including violet, which excites OBAs and perfectly renders whites. The research study at Penn State showed that the vast majority of participants preferred objects rendered under Soraa’s full visible spectrum light over standard LED light that lacked the short wavelength range of the spectrum. In fact, whether looking at a white dress shirt or their own smile, 90% of users preferred the whiteness rendering provided by Soraa’s lamps.

As for colors, study participants commented that colors were more saturated, vibrant and attractive under Soraa’s full visible spectrum LED lamps with VP3 Vivid Color (color rendering index (CRI) of 95 and R9 of 95) versus the blue-based LED lamps with a standard CRI of 85 and R9 of 0. The research showed that the company’s VP3 technology rendered colors with high fidelity and no change in saturation; and the colors accurately matched the reference halogen lamp. This was true not only for colored objects, but also for participants’ skin complexions.

“There are those who’ve asked: does color and whiteness rendering really matter?  Well, it does, and we now have the data to prove it,” said Mike Krames, CTO of Soraa. “Because all of our lamps render the entire visible spectrum, white fabrics and paper goods pop, plastics are brilliant and people’s smiles are whiter, and colors are more natural and beautiful.  That’s good news for consumers and retailers, who want and deserve the enormous economic and environmental benefits of LED lighting, but are unwilling to sacrifice the sales benefits of excellent light quality in return.”

Kateeva  announced that it has closed its Series D round with $38 million in financing. The newest participant is Samsung Venture Investment Corporation (SVIC). Existing investors also contributed. They include: Sigma Partners, Spark Capital, Madrone Capital Partners, DBL Investors, New Science Ventures, and VEECO Instruments, Inc.

The company has raised more than $110 million since it was founded in 2008.

Kateeva makes the YIELDjet™ platform — a precision deposition platform that leverages inkjet printing to mass produce flexible and large-size OLED panels. The new funds will be used to support the company’s manufacturing strategy and expand its global sales and support infrastructure. Production systems are currently being built at the company’s facility in Menlo Park, Calif. to fulfill early orders.

The funding news coincides with the 2014 OLEDs World Summit taking place this week in Berkeley, Calif.

“Kateeva is a technology leader and has built a significant business in the OLED space,” said Michael Pachos, Senior Investment Manager at SVIC. “The company has demonstrated both a technical and business vision in driving adoption of OLED displays and lighting, and we look forward to contributing to its progress.”

“We believe that OLEDs on flexible substrates play a major role in the insatiable quest for ultra-durable, high-performance, and unbreakable mobile displays, and Kateeva has proven to hold the keys to a critical industry problem,” said Fahri Diner, Managing Director of Sigma Partners and a member of the Board of Directors of Kateeva. “Moreover, we are very excited about Kateeva’s impressive innovations that are poised to make large-panel OLED televisions finally an affordable reality — perhaps the Holy Grail of the display world. In partnership with SVIC, we’re delighted to offer continued support to Kateeva as they rapidly scale operations to support accelerating demand for OLED manufacturing solutions,” Diner continued.

Kateeva Chief Executive Officer Alain Harrus said: “SVIC’s investment speaks volumes about our technology’s enabling value to world-class OLED producers. It will reinforce our leading position and help serve all our customers better. Also, we appreciate our existing investors for their enduring commitment and trusted guidance. Thanks to their confidence in our technology and execution, mass producing OLEDs will be much smoother for leading display manufacturers.”

CEA-Leti and LUCIOM, which develops visible-light communication using light-emitting diodes (LEDs), have launched a project to develop high-data-rate LiFi transceivers. With this technology, LUCIOM expects to offer in mid-2015 one of the first high-data-rate bidirectional light-fidelity, or LiFi, products that can work with different LED lighting sources, and on mobile devices.

Visible light communications (VLC) has gained significant momentum in recent years, primarily because of expectations that LEDs will become predominant in the lighting market. As LiFi benefits from this rapid market penetration of LED lighting sources and their reduced cost, it will become more efficient and economical compared to wireless RF communications.

Moreover, because LEDs can be modulated at very high frequencies and their oscillations are invisible to humans, they permit information transmission at very high data rates.

Earlier this year, Leti demonstrated a new prototype for wireless high-data-rate Li-Fi transmission. The technology employs the high-frequency modulation capabilities of LED engines used in commercial lighting. It achieves throughputs of up to 10Mb/s at a range of three meters, suitable for HD video streaming or Internet browsing, using light power of less than 1,000 lumens and with direct or even indirect lighting. This technology will be adapted to meet the needs of LUCIOM’s transceivers.

LUCIOM’s technology allows the convergence of light-emitting diodes with the worldwide proliferation of mobile devices to make any LED lighting source a high-speed data transmitter that is both secure and environmentally friendly.

Based on integrated circuits and transceivers, the technology turns LED light sources into positioning beacons, which transmit signals. This allows smartphones and tablets to become LiFi enabled, thanks to a receiver that is implemented in a 3.5mm audio jack dongle. The compact size of the receiver eases the integration in the device. In addition, the audio remains accessible from the audio interface, even when the LiFi application is launched from a smartphone.

LUCIOM’s technology can be combined with the use of gyro-sensors present in smartphones and tablets to predict movement between two beacons and provide a very accurate position to the user. This way, communication between phones and smart indoor LED lighting can be used inside buildings when GPS technology is no longer effective. The localization application can also be used to provide additional personalized services or information to customers as well as information to the infrastructure manager.

In addition to these indoor-positioning applications, the company is targeting high-data-rate video transfer.The project between Leti and LUCIOM builds on their previous collaboration in which Leti developed an optical over-the-air data link for the company that allows the transmission of true HD video from a lamp to a handheld receiver.

“Our indoor geo-localization could guide shoppers through the maze of large shopping malls to the stores they are seeking, and LED lighting in museums could be used to guide visitors through an enriched tour of the displays and exhibits,” said Michel Germe, CEO of LUCIOM. “Working again with Leti, we will be able to bring new, bidirectional transceivers that enable these applications to market in 2015.”

“LUCIOM was one of the first companies to see that LEDs and LiFi can offer a powerful, secure and highly energy-efficient communications alternative to WiFi,” said Leti CEO Laurent Malier. “With Leti’s first proof of concept developed earlier this year and its expertise in RF communications, we expect data-transmission rates in excess of 100Mb/s with traditional lighting based on LED lamps.”

Intematix Corporation, a manufacturer of phosphor solutions for LED lighting, has collaborated with SABIC’s Innovative Plastics business to create the ChromaLit Linear – a LED offering developed for the lighting industry.  By using Intematix’s remote phosphor technology and SABIC’s LEXAN LUX resins, lighting customers can now achieve the energy efficiency and reliability benefits of LEDs, while also experiencing increased optical efficiency and better light uniformity-a critical factor for commercial environments.

“SABIC is excited to have worked with Intematix to design a solution that successfully addresses a historic challenge with LED lighting used in commercial applications. In addition to being more efficient, the new LED system can be both extruded and injection molded,”  said Venugopal Koka, Director of Electrical Industrial and Lighting Marketing for SABIC’s Innovative Plastics business.

Remote phosphor is a lighting system technology that uses a phosphor component separated from the blue LED energy source. The independent phosphor emits light when excited by blue light. When the phosphor has been separated from the energy source it results in better lighting uniformity and consistency. Intematix selected SABIC’s LEXAN LUX transparent, diffusion and reflective grades for their ChromaLit Linear remote phosphor offering for their superior efficiency and flexible processing capabilities. In addition, the LEXAN LUX base material provides a UL94 flame rating of V0.

Linear light sources are in widespread use for illuminating commercial and industrial applications worldwide. Office lighting and other commercial applications have been challenging for white LEDs because of the need to diffuse the point sources, reducing system efficacy.  The ChromaLit Linear product delivers naturally uniform, high-quality light with conversion efficacy of up to 215 lumens per radiant watt or up to 163 lumens per system watt when used with the most efficient blue LEDs available.

“We expect a whole new set of valuable remote phosphor solutions to emerge as we draw upon SABIC’s world-class expertise in advanced thermoplastics,” said Mark Swoboda, Chief Executive Officer for Intematix. “Our experience has demonstrated that bringing our two companies’ innovations together results in ground-breaking products that accelerate market adoption of LED-based lighting systems.”

Following Intematix’s successful commercialization of the ChromaLit Linear, SABIC’s Innovative Plastics business and Intematix will continue to collaborate on new technology developments to help enable lighting OEMs to take advantage of expanded remote phosphor solutions for solid-state lighting (SSL). The continued collaboration will allow Intematix and SABIC to further combine their complementary expertise driving the development of new applications, technologies and materials which can hasten and optimize the commercialization of new LED products, platforms and lighting applications.

Cree, Inc. has announced that its C2M, 1200V, 80mOhm SiC MOSFETs have been selected by Sanix Corporation, Japan, to be designed into their new 9.9kW three-phase solar inverters for use in the construction of commercial photovoltaic systems in the fast-growing Japanese solar energy market.

“Through this partnership with Cree and their SiC technology, Sanix is able to capture more market share in the competitive Japan solar market,” said Hiroshi Soga, general manager, Sanix Incorporated. “Cree’s silicon carbide MOSFETs were critical for Sanix to meet our efficiency and thermal design targets. SiC switches reduced losses in our inverter electronics by more than 30 percent versus the silicon super-junction MOSFETs we were considering. In addition to providing a large efficiency gain, Cree’s latest generation C2M SiC MOSFETs were priced competitively, making it possible to replace lower voltage, less rugged, and less efficient silicon MOSFETs.”

Utilized in the primary power conversion stage of the solar inverter, Cree’s 1200V C2M0080120D MOSFETs feature faster switching characteristics and up to one-third the switching losses of comparably-rated 900V silicon super-junction MOSFETs. By significantly reducing switching losses, Cree’s SiC MOSFETs enable lower total system energy losses, higher frequency switching, and cooler operating temperatures. These benefits improve conversion efficiency and reduce the system’s size, weight, complexity, and thermal management requirements. At the system level, performance is improved, cost is decreased, and lifetime of the inverter is extended.

“Cree is extremely pleased that Sanix has chosen to specify our C2M, 1200V SiC MOSFET technology in its new 9.9kW solar inverters. Cree SiC power devices can provide significant advantages with regard to PV inverter efficiency, reliability, and cost, and will provide Sanix with a critical competitive advantage as they continue to expand their share of the Japanese solar market,” said Cengiz Balkas, general manager and vice president, Cree Power and RF.

Demonstrated to achieve up to three times the power density of typical silicon technology, Cree’s C2M family of SiC MOSFETs are available in 1200V and 1700V, ranging from 1Ω to 25 mΩ. C2M MOSFETs have been designed into a range of industrial power applications since their March 2013 market introduction and continue to experience increasing demand. Cree is currently delivering production volumes of SiC MOSFETs to Sanix and other PV inverter manufacturers, as well as to makers of industrial power supplies, auxiliary power converters, battery chargers, and motor drives.

Seoul Semiconductor announced the release of a new LED light engine with Acrich 3 technology on August 27, 2014. The new light engine is comprised of an LED module with Acrich MJT 5050 series LED, Acrich3 IC technology, and a heat sink and secondary optics. The Acrich light engine does not require a complex AC/DC converter and can be operated directly from the AC mains which simplifies designs, reduces component count and improves on the reliability of the luminaire. This new 30W Acrich light engine delivers a typical luminous flux of 3000 lumens at 120VAC operation at 5000K corresponding to a typical efficiency of 100 lumens per watt. When operated in a power compensation mode the Acrich3 technology can adapt to variations in the line-voltage as great as 20% and still deliver power-level regulation within 5% to ensure uniformity of the light output.

The new Acrich3 solution enables smart lighting control systems where the Acrich3 technology can interface through a wide variety of wireless networks such as IEEE 802.15.4, WiFi, and Bluetooth to control dimming, and further optimize on energy savings. This IP67 light engine is available in various color temperatures and beam patterns.

Seoul Semiconductor Executive Vice President of Lighting sales division, Jay Kim has stated that, “The payback period for streetlights can be significantly reduced with this new Acrich light engine. By eliminating AC/DC converters in streetlights, maintenance costs can be lowered and reliability can be improved without compromising on price, quality and energy savings to dramatically improve the lighting experience for customers. This product will enable the market to come up with the next generation of high quality, energy efficient and competitively priced LED lamps.”

Read more: Seoul Semiconductor moves in to the Top 5 global LED manufacturers

SemiLEDs Corporation, a global provider of vertical LED technology solutions, today announced sampling and volume availability of the first in its new Enhanced FlipChip, or EF, LED series.

The series launches with the EF-B40, a blue 40-mil flip chip that simplifies the packaging and integration process by eliminating wire-bonding while increasing both lumen-density and decreasing the lumen-per-dollar value proposition while enabling packagers to use standard surface mount assembly techniques.

“SemiLEDs’ unique flip chip approach combines a sapphire front surface and proprietary back side architecture that provides the electrical contacts exclusively on the bottom of the chip, making it fully compatible with chip-on-board (COB) surface mount processes,” Mark Tuttle, General Manager for SemiLEDs Optoelectronics Co., Ltd., explained. “Eliminating wire-bonds also lowers the profile of the chips, and allows them to be placed more closely together, which results in higher lumen-density and reduces the complexity of the optics. The EF series is an ideal platform for COB assemblies, or really for any approach that calls for either secondary optic design or high-density mounting.”

Flip chip construction presents what was originally the bottom sapphire layer in a horizontal LED structure as the top surface of the chip. By “flipping” the chip in this manner, the electrical pads become part of the bottom of the device rather than running bonding wires from the top surface of the chip down to the package or board. Not only are delicate areas of the chip protected by the clear sapphire layer, but by eliminating wire bonds, arguably the most failure-prone part of any LED assembly, both reliability and overall design flexibility of the packaged device are increased. In addition, individual chips may be more closely mounted, opening the door to more densely packed arrays of LED chips. The nearly continuous light emitting surface, unbroken by gaps, bonding wires, or top electrodes, can greatly simplify the mounting and mixing requirements of the optics, producing smooth lighting effects. In addition, in a flip chip structure, the heat-generating junction is positioned adjacent to the substrate, increasing thermal conductivity and allowing improved device performance at high currents.

The EF-B40 is available in wavelengths from 445 to 460nm, with outputs of up to 300 lumens at 1A as a packaged emitter. The SAC compatible chips are offered with standard Au bonding pads, or are available with an AuSn option to further reduce thermal resistance and add to system reliability. A 140-degree viewing angle makes the EF ideal for general and commercial lighting, while the lowered profile addresses the application needs of LED backlight, smartphone flash or LED projector.

SemiLEDs’ EF series of LED chips are RoHS compliant with production quantities available now.

Quantum Materials Corporation today announced the purchase of five diverse sets of patent families from Bayer Technology Services GmbH, the global technological backbone and major innovation driver for Bayer AG of Leverkusen, Germany.

The patents acquired provide broad intellectual property protection for advances Quantum Materials has achieved in economical high-volume quantum dot (QD) manufacturing. In addition, the Bayer patents cover volume production technology for heavy metal-free (HMF) quantum dots and nano-particles; increasing quantum yields for HMF quantum dots; and hybrid organic quantum dot solar cell (QDSC) production as well as a surface modification process for increased efficiency of high performance solar cells and printed electronics. The patent families were acquired through a cash purchase agreement and financial details will remain private.

“We acquired these patents to not only expand our technology portfolio in heavy metal-free and QDSC production, but also to protect the advances we have made to date in the volume manufacturing of nanoparticles, including quantum dots,” said Stephen Squires, Quantum Materials CEO and president.  “Bayer is a research pioneer in the nanotech and QD fields and these early filings were awarded with broad claims. It will be very difficult for competitors to produce materials in volume similar to ours without breaching our patents.”

“Bayer Technology Services has been successfully working in the field of nanotechnology for more than 30 years. We are very happy that Quantum Materials is also using our patents to invest into new markets Bayer is not focusing on,” adds Dr. Guenter Bachlechner, Head of Technology Development and Senior Vice President of Bayer Technology Services GmbH.

The quantum dot-related patents extend Quantum Materials’ ability to synthesize numerous heavy metal-free organic periodic table groups in addition to its own inorganic Group II-VI composites. The company intends to incorporate each patent into its advanced production processes, including high yield InP/ZnS nanocrystals, a heavily researched QD in high demand in optoelectronics.

The solar-related patents describe the fundamental design of quantum dot solar cells and processes for optimizing quantum dots for solar and other printed electronics applications. The solar patents enhance Quantum Material’s licensed patent on printing OLED and QD solar cells and other printed electronic devices by gravure or high-speed roll-to-roll.

David Doderer, Quantum Materials VP of Research and Development, added, “The heavy metal-free organic nanomaterials expand our high performance product offerings, and the automated processes will bring down their cost so manufacturers can begin planning adoption into real products at price points that expand market penetration of quantum dot  technologies significantly. Combining the solar patents with our automated volume QD production process opens the door for us to establish joint ventures for Quantum Dot Solar Cell (QDSC) pilot plants worldwide.”

USHIO INC. announced that its wholly owned subsidiary USHIO OPTO SEMICONDUCTORS, INC., headquartered in Tokyo, has signed a demerger agreement with Oclaro Japan, Inc. Through this agreement, USHIO OPTO SEMICONDUCTORS will acquire the LED, red, violet and part of the infrared laser diode business from Oclaro Japan. The acquired activity is primarily located in Komoro, Japan and includes approximately 80 employees.

Since it was founded five decades ago, USHIO has developed, manufactured, and marketed a variety of successful and highly popular lamps and solid-state light sources. USHIO has long been one of the world’s leading manufacturers of industrial light sources. By this transfer, USHIO is aiming at further expansion of its solid-state light sources business. USHIO will receive transfer of the business related to the development, manufacture, and sales of semiconductor lasers and LEDs (other than Oclaro Japan’s optical communication business) from Oclaro Japan.

“Today, optical processes and applications have become more and more diversified and important in the industry. We at USHIO will provide a variety of light sources, including high-brightness and high-quality LEDs and LDs, as well as our existing lamp products to meet the diversified needs of our customers,” commented Shiro Sugata, President and CEO, USHIO INC.

“We are pleased to sign this agreement with Ushio, it was critical for Oclaro Japan to find a respected partner that would provide new opportunities to our Komoro employees and continued support and innovation to our customers.” commented Tadayuki Kanno, President of Oclaro Japan.

The closing of the transaction is expected to occur during the fourth calendar quarter of 2014.