Bringing Quantum Dots into Sharp Focus: QD Makers Scale Up to Meet Demand: $9.6B Display Market by 2023


QDOT images 3When Amazon.com Inc was developing its most advanced tablet to date, it asked a little-known company to solve a tricky problem with the screen: how to produce rich colors without draining battery life.

With the help of Milpitas, California-based Nanosys Inc, the Kindle Fire HDX 7 became one of Amazon’s best-selling tablets, winning critical acclaim for its vibrant display.

The answer? Quantum dots, which are semiconductor crystals 10,000 times finer than a human hair. They convert electrical energy into light and can be manipulated to produce precise colors.

“If you put a regular LCD display next to a quantum-dot LCD display, your grandmother can tell the difference,” said Jason Carlson, chief executive officer of QD Vision Inc, which makes quantum dots for Sony Corp’s Triluminos TV.

3D Printing dots-2

So explosive is demand for this technology that the few companies able to make quantum dots are struggling to keep up. Most are partnering with big display makers to set up industrial-scale manufacturing.

QD Vision and Nanosys are considering going public in the next year or so.

But while quantum dots are cheaper and consume less power than organic light-emitting diodes (OLED), their rival technology at the sharp end of the display business, they cannot yet be produced in the same quantities.

Quantum dots from most suppliers also contain cadmium, a toxic metal whose use is restricted in many countries.

A recent survey by DisplayMate Technologies rated Amazon’s Kindle Fire display as the clear winner in color reproduction against Apple Inc’s iPad mini and Google Inc’s Nexus 7. (bit.ly/1tn58ze)

Smartphone and TV consumers also like quantum dots for their low price. A 65-inch quantum-dot display TV would cost about $3,500, half as much as an OLED-display model of the same size, said Nutmeg Consultants founder Ken Werner.

Werner said quantum dots would retain that pricing advantage for at least three years.

For that reason, the OLED market cannot match the growth rates forecast for quantum dots.

Touch Display Research analyst Jennifer Colegrove said she expected a $9.6 billion market for quantum-dot displays and lighting components by 2023, compared with sales of just $75 million last year. (bit.ly/1mceJ7j)

By contrast, Transparency Market Research projects annual sales of OLED displays at $25.9 billion by 2018 versus $4.9 billion in 2012.

QUANTUM LEAP

Although quantum dots have been in development since the 1980s, they have only made the leap from laboratory to market in the last decade.

Nanosys shelved its plan to go public in 2004 for want of a viable product. Now the company says an initial public offering is its next step.

Lexington, Massachusetts-based QD Vision considers an IPO to be a possibility in 2015, Carlson said.

Two other quantum dot makers plan to shift their listings to larger exchanges, their CEOs told Reuters. Nanoco Group Plc will move to the London Stock Exchange from the bourse’s AIM, and San Marcos, Texas-based Quantum Materials Corp will go to the New York Stock Exchange or Nasdaq from over the counter.

To supply the volumes needed for large-scale manufacturing, QD Vision has partnered with LG Display Co Ltd, while Nanosys has a manufacturing partnership with a unit of 3M Co.

The shift from OLED technology toward quantum dots has been especially prevalent in TV, where OLED panels have proven expensive for large screens.

Sony and Panasonic Corp, Japan’s two largest consumer electronics companies, in December announced an end to their joint development of OLED TV screens.

PATENT POWER

Patents on the technology used to make quantum dots will make it tough for new entrants to unseat existing producers, said IHS Technology analyst Brian Bae.

Apple last year filed patents on quantum-dot technology, but they involve improving the brightness and quality of displays rather than manufacturing. (1.usa.gov/1rmlKlw)

Even cadmium, which the European Union and other countries restrict for use in electrical and electronic equipment, may not be much of a problem.

Oeko-Institut, an independent research institute hired by the EU, has recommended that quantum dots be exempt from wider legislation on hazardous substances until July 1, 2017, provided the cadmium content per square millimeter of display screen is below 0.2 micrograms.

That is above what is contained in displays with Nanosys and QD Vision’s technologies.

For Nanoco, however, the prospect of stricter regulation beyond 2017 might be an advantage. It is the only producer of cadmium-free quantum dots and has recently doubled capacity at its Runcorn plant in northwest England.

The company has a licensing deal with a unit of Dow Chemical Co, which holds exclusive worldwide rights for the sale of its quantum dots for use in electronic displays.

Nanoco CEO Michael Edelman said Dow Electronic Materials had “the engineering strength and muscle to scale into the volumes that are necessary – and quickly.”

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Perovskite: New Wonder Material to make Cheaper & Easier to Manufacture LED’s


 

 

ledsmadefromColourful LEDs made from a material known as perovskite could lead to LED displays which are both cheaper and easier to manufacture in future. 

A hybrid form of perovskite – the same type of material which has recently been found to make highly efficient solar cells that could one day replace silicon – has been used to make low-cost, easily manufactured LEDs, potentially opening up a wide range of in future, such as flexible colour displays.

This particular class of semiconducting perovskites have generated excitement in the solar cell field over the past several years, after Professor Henry Snaith’s group at Oxford University found them to be remarkably efficient at converting light to electricity. In just two short years, perovskite-based solar cells have reached efficiencies of nearly 20%, a level which took conventional silicon-based 20 years to reach.

ledsmadefrom

Now, researchers from the University of Cambridge, University of Oxford and the Ludwig-Maximilians-Universität in Munich have demonstrated a new application for perovskite , using them to make high-brightness LEDs. The results are published in the journal Nature Nanotechnology.

Perovskite is a general term used to describe a group of materials that have a distinctive crystal structure of cuboid and diamond shapes. They have long been of interest for their superconducting and ferroelectric properties. But in the past several years, their at converting light into electrical energy has opened up a wide range of potential applications.

The perovskites that were used to make the LEDs are known as organometal halide perovskites, and contain a mixture of lead, carbon-based ions and halogen ions known as halides. These materials dissolve well in common solvents, and assemble to form perovskite crystals when dried, making them cheap and simple to make.

“These organometal halide perovskites are remarkable semiconductors,” said Zhi-Kuang Tan, a PhD student at the University of Cambridge’s Cavendish Laboratory and the paper’s lead author. “We have designed the diode structure to confine electrical charges into a very thin layer of the perovskite, which sets up conditions for the electron-hole capture process to produce light emission.”

The perovskite LEDs are made using a simple and scalable process in which a perovskite solution is prepared and spin-coated onto the substrate. This process does not require high temperature heating steps or a high vacuum, and is therefore cheap to manufacture in a large scale. In contrast, conventional methods for manufacturing LEDs make the cost prohibitive for many large-area display applications.

“The big surprise to the semiconductor community is to find that such simple process methods still produce very clean semiconductor properties, without the need for the complex purification procedures required for traditional semiconductors such as silicon,” said Professor Sir Richard Friend of the Cavendish Laboratory, who has led this programme in Cambridge.

“It’s remarkable that this material can be easily tuned to emit light in a variety of colours, which makes it extremely useful for colour displays, lighting and optical communication applications,” said Tan. “This technology could provide a lot of value to the ever growing flat-panel display industry.”

The team is now looking to increase the efficiency of the LEDs and to use them for diode lasers, which are used in a range of scientific, medical and industrial applications, such as materials processing and medical equipment. The first commercially-available LED based on perovskite could be available within five years.

Explore further: Scientists develop pioneering new spray-on solar cells

More information: Nature Nanotechnology, www.nature.com/nnano/journal/v… /nnano.2014.149.html

Read more at: http://phys.org/news/2014-08-material-perovskite.html#jCp

Translating Science into Business: The Business of Organic Semiconductors


 

KAUST karl

“There are many things which can go wrong when starting a company; but the worst thing that can go wrong is to not do it,” said Prof. Karl Leo, Director of KAUST’s Solar & Photovoltaics Engineering Research Center, when speaking at an Entrepreneurship Center speaker series event this past spring. Wearing the dual hats of scientist and entrepreneur, Prof. Leo is the author of 440 publications, holds more than 50 patents, and has co-created 8 companies which have generated over 300 jobs.

A physicist by training, Prof. Leo highlighted the point that he is primarily a scientist who stumbled onto business by chance. “For me it’s always started with and been about the science,” he says. All his spin-off companies came about as a result of basic research he and his group conducted on organic semiconductors. Speaking specifically to the young KAUST researchers hoping to emulate his success as academics and entrepreneurs, Prof. Leo said: “The message I want to pass along is if you really want to do things, just be curious. Don’t say I want to do research to make a company. Do very basic research and the spin-off ideas will come along.”

The Growing Influence of Organic Semiconductors

Prof. Karl Leo started doing research on organic semiconductors about 20 years ago. He has since been passionate about this field’s developments and future potential. Despite his early skepticism resulting from the ephemeral lifetime of organic semiconductors in the ’90s, the performance levels of LED devices for instance have gone from just a few minutes of useful life then to virtually not aging today. “In the long-term, as in 20 to 30 years from now, almost everything will be organics,” he believes. “Silicon has dominated electronics for a long time but organic is something new.” Organic products have evolved into a variety of applications such as: small OLED displays, OLED televisions, OLED lighting, OPV and organic electronics.

Organics, as opposed to traditional silicon-based semiconductors, are by nature essentially lousy semiconductors. Mobility, or the speed at which electrons move on these materials, is a really important property. However, when looking at the electronic properties of semiconductors, carbon offers interesting developments for the performance of organics. For instance, graphene, which is a carbon-based organic material, has even higher mobility than silicon.

Organic Semi untitled

One of the companies Prof. Karl Leo co-founded and began operating out of Dresden, Germany in 2003, Novaled, became a leader in in organic light-emitting diode (OLED) field. OLEDs are made up of multiple thin layers of organic materials, known as OLED stacks. They essentially emit light when electricity is applied to them. Novaled became a pioneer in developing highly efficient and long-lifetime OLED structures; and it currently holds the world record in power efficiency. They key to Novaled’s success, as Prof. Leo explains, is “the simple discovery that you can dope organics.” This was a major breakthrough achieved simply adding a very little amount of another molecule.

This organic conductivity doping technology, used to enhance the performance of OLED devices, was the main factor leading to the company being purchased by Samsung in 2013.

Organic Photovoltaics: Technology of the Future

Following the successful commercial penetration of OLED displays in the consumer electronics market, Prof. Karl Leo has since turned his focus on organic photovoltaics. “I think organic PV is something that can change the world,” said Leo. Among the many advantages of organic photovoltaics are that they are thin organic layers which can be applied on flexible plastic substrates. They consume little energy, can be made transparent, and are compatible with low-cost large-area production technologies. Because they are transparent, they can be made into windows for instance, and also be manufactured in virtually any color. All these characteristics make organic PV ideal for consumer products.

Again based on basic research conducted by his group, Prof. Leo also started a company, Heliatek, which is now a world-leader in the production of organic solar film. Heliatek has developed the current world record in the efficiency of transparent solar cells. The company also holds the record for efficiency of opaque cells at 12 percent. Leo believes that it’s possible to achieve up to 20 percent efficiency in the near future, which will be necessary to compete with silicon and become commercially viable.

Don’t Believe Business Plans

Prof. Leo explained that the experience he and his team gained from launching a successful company like Novaled helped them to both define the objectives and obtain funding from investors for his solar cell company, Heliatek. “Once you create a successful company, things get much easier,” he said. But Leo also cautioned the budding entrepreneurs in the audience to be willing to adapt as they present and implement their ideas.

“If you have a good idea and you are convinced you have a good idea, never give up,” he said. But being able to adapt to market needs is also crucial. For instance, Leo’s original business plan for Novaled focused on manufacturing displays. But the realities of the market, and the prohibitive cost of manufacturing displays, convinced his team that the smarter way to go was to supply materials. At the end of the day, what really succeeded in getting a venture capital firm’s attention, after haven been told no 49 times, was his team’s ability to demonstrate the value of the technology.

“Business plans are useful but they must not be overestimated,” said Prof. Leo. Business plans are a good indicator of how entrepreneurs are able to structure their thoughts, identify markets and create a roadmap, but “nobody is able to predict the future in a business plan; it’s not possible.”

 

Definition of Organic Semi-Conductors: Background

An organic semiconductor is an organic material with semiconductor properties, that is, with an electrical conductivity between that of insulators and that of metals. Single molecules, oligomers, and organic polymers can be semiconductive. Semiconducting small molecules (aromatic hydrocarbons) include the polycyclic aromatic compounds pentacene, anthracene, and rubrene. Polymeric organic semiconductors include poly(3-hexylthiophene), poly(p-phenylene vinylene), as well as polyacetylene and its derivatives.

There are two major overlapping classes of organic semiconductors. These are organic charge-transfer complexes and various linear-backbone conductive polymers derived from polyacetylene. Linear backbone organic semiconductors include polyacetylene itself and its derivatives polypyrrole, and polyaniline.

At least locally, charge-transfer complexes often exhibit similar conduction mechanisms to inorganic semiconductors. Such mechanisms arise from the presence of hole and electron conduction layers separated by a band gap.

Although such classic mechanisms are important locally, as with inorganic amorphous semiconductors, tunnelling, localized states, mobility gaps, and phonon-assisted hopping also significantly contribute to conduction, particularly in polyacetylenes. Like inorganic semiconductors, organic semiconductors can be doped. Organic semiconductors susceptible to doping such as polyaniline (Ormecon) and PEDOT:PSS are also known as organic metals

 

Further Information

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SUBCOMMITTE EXAMINES BREAKTHROUGH NANOTECHNOLOGY OPPORTUNITIES FOR AMERICA

Chairman Terry: “Nanotech is a true science race between the nations, and we should be encouraging the transition from research breakthroughs to commercial development.”

WASHINGTON, DCThe Subcommittee on Commerce, Manufacturing, and Trade, chaired by Rep. Lee Terry (R-NE), today held a hearing on:

“Nanotechnology: Understanding How Small Solutions Drive Big Innovation.”

 

 

electron-tomography

“Great Things from Small Things!” … We Couldn’t Agree More!

 

Quantum Dots may turn House Windows into Solar Panels


 

New-QD-Solar-Cell-id35756-150x150A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work by researchers at Los Alamos National Laboratory in the US in collaboration with scientists from University of Milano-Bicocca (UNIMIB) in Italy.

Their work, published earlier this year in Nature Photonics, demonstrates that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight.

“The key accomplishment is the demonstration of large-area luminescent solar concentrators that use a new generation of specially engineered quantum dots,” said lead researcher Victor Klimov of the Center for Advanced Solar Photophysics at Los Alamos. Quantum dots are ultra-small bits of semiconductor matter that can be synthesized with nearly atomic precision via modern methods of colloidal chemistry.

A luminescent solar concentrator (LSC) is a photon-management device, representing a slab of transparent material that contains highly efficient emitters such as dye molecules or quantum dots. Sunlight absorbed in the slab is re-radiated at longer wavelengths and guided toward the slab edge equipped with a solar cell.

Quantum dots are embedded in the plastic matrix and capture sunlight to improve solar-panel efficiency.
Courtesy Los Alamos Lab.
 
LUMINESCENT SOLAR CONCENTRATOR AS LIGHT HARVESTER

Sergio Brovelli, a faculty member at UNIMIB and a co-author of the paper, explained, “The LSC serves as a light-harvesting antenna which concentrates solar radiation collected from a large area onto a much smaller solar cell, and this increases its power output. LSCs are especially attractive because in addition to gains in efficiency, they can enable new interesting concepts such as photovoltaic windows that can transform house facades into large-area energy-generation units.”

Because of highly efficient, color-tunable emission and solution processability, quantum dots are attractive materials for use in inexpensive, large-area LSCs. To overcome a nagging problem of light reabsorption, the Los Alamos and UNIMIB researchers developed LSCs based on quantum dots with artificially induced large separation between emission and absorption bands, known as a large Stokes shift.

These “Stokes-shift-engineered” quantum dots represent cadmium selenide/cadmium sulfide (CdSe/CdS) structures in which light absorption is dominated by an ultra-thick outer shell of CdS, while emission occurs from the inner core of a narrower-gap CdSe.

Los Alamos researchers created a series of thick-shell (so-called “giant”) CdSe/CdS quantum dots, which were incorporated by their Italian partners into large slabs (sized in tens of centimeters across) of polymethylmethacrylate. While being large by quantum dot standards, the active particles are still tiny, only about hundred angstroms across.

QUANTUM DOTS USED FOR NEW DISPLAYS

Quantum dots are ultra-small bits of semiconductor matter that can be synthesized with nearly atomic precision via modern methods of colloidal chemistry.

Their emission color can be tuned by simply varying their dimensions. Color tunability is combined with high emission efficiencies approaching 100%.3D Printing dots-2

These properties have recently become the basis of a new technology — quantum-dot displays — employed, for example, in the newest generation of the Kindle Fire e-reader.

In a new SPIE.TV video, Lawrence Berkeley National Lab director Paul Alivisatos demonstrates the Kindle Fire quantum-dot display.

 

DOI: 10.1117/2.4201407.10

Subcommittee Examines Breakthrough Nanotechnology Opportunities for America


Applications-of-Nanomaterials-Chart-Picture1SUBCOMMITTE EXAMINES BREAKTHROUGH NANOTECHNOLOGY OPPORTUNITIES FOR AMERICA
July 29, 2014

WASHINGTON, DCThe Subcommittee on Commerce, Manufacturing, and Trade, chaired by Rep. Lee Terry (R-NE), today held a hearing on “Nanotechnology: Understanding How Small Solutions Drive Big Innovation.” Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is approximately 1 to 100 nanometers (one nanometer is a billionth of a meter). This technology brings great opportunities to advance a broad range of industries, bolster our U.S. economy, and create new manufacturing jobs. Members heard from several nanotech industry leaders about the current state of nanotechnology and the direction that it is headed.UNIVERSITY OF WATERLOO - New $5 million lab

“Just as electricity, telecommunications, and the combustion engine fundamentally altered American economics in the ‘second industrial revolution,’ nanotechnology is poised to drive the next surge of economic growth across all sectors,” said Chairman Terry.

 

 

Applications of Nanomaterials Chart Picture1

Dr. Christian Binek, Associate Professor at the University of Nebraska-Lincoln, explained the potential of nanotechnology to transform a range of industries, stating, “Virtually all of the national and global challenges can at least in part be addressed by advances in nanotechnology. Although the boundary between science and fiction is blurry, it appears reasonable to predict that the transformative power of nanotechnology can rival the industrial revolution. Nanotechnology is expected to make major contributions in fields such as; information technology, medical applications, energy, water supply with strong correlation to the energy problem, smart materials, and manufacturing. It is perhaps one of the major transformative powers of nanotechnology that many of these traditionally separated fields will merge.”

Dr. James M. Tour at the Smalley Institute for Nanoscale Science and Technology at Rice University encouraged steps to help the U.S better compete with markets abroad. “The situation has become untenable. Not only are our best and brightest international students returning to their home countries upon graduation, taking our advanced technology expertise with them, but our top professors also are moving abroad in order to keep their programs funded,” said Tour. “This is an issue for Congress to explore further, working with industry, tax experts, and universities to design an effective incentive structure that will increase industry support for research and development – especially as it relates to nanotechnology. This is a win-win for all parties.”

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Professor Milan Mrksich of Northwestern University discussed the economic opportunities of nanotechnology, and obstacles to realizing these benefits. He explained, “Nanotechnology is a broad-based field that, unlike traditional disciplines, engages the entire scientific and engineering enterprise and that promises new technologies across these fields. … Current challenges to realizing the broader economic promise of the nanotechnology industry include the development of strategies to ensure the continued investment in fundamental research, to increase the fraction of these discoveries that are translated to technology companies, to have effective regulations on nanomaterials, to efficiently process and protect intellectual property to ensure that within the global landscape, the United States remains the leader in realizing the economic benefits of the nanotechnology industry.”

James Phillips, Chairman & CEO at NanoMech, Inc., added, “It’s time for America to lead. … We must capitalize immediately on our great University system, our National Labs, and tremendous agencies like the National Science Foundation, to be sure this unique and best in class innovation ecosystem, is organized in a way that promotes nanotechnology, tech transfer and commercialization in dramatic and laser focused ways so that we capture the best ideas into patents quickly, that are easily transferred into our capitalistic economy so that our nation’s best ideas and inventions are never left stranded, but instead accelerated to market at the speed of innovation so that we build good jobs and improve the quality of life and security for our citizens faster and better than any other country on our planet.”

Chairman Terry concluded, “Nanotech is a true science race between the nations, and we should be encouraging the transition from research breakthroughs to commercial development. I believe the U.S. should excel in this area.”

– See more at: http://energycommerce.house.gov/press-release/subcommittee-examines-breakthrough-nanotechnology-opportunities-america#sthash.YnSzFU10.dpuf

Flexible Glass for the Display Industry? Not So Fast!


EcoTCO1-250** From NanoMarkets LC July 21st, 2014

 

Flexible glass seemed like a natural fit for the display industry, combining the impermeability of glass with the flexibility of plastic. In 2012 it appeared as though flexible and ultrathin glass companies were going to benefit from the explosion of touch screens in displays of all sizes. Unfortunately, the market took a different turn. Now suppliers of ultrathin and flexible glass are looking for applications beyond displays to bring in revenue in the next few years, and one of the places they are looking is in semiconductor packaging.

For those who approach flexible glass from the point of view of a display, an application where the glass is hidden between layers of silicon and other materials may not seem to make a lot of sense. As far as NanoMarkets can tell, no one really thought about semiconductor packaging as a use for flexible glass until the display market failed to emerge as an opportunity.

Nonetheless, using ultrathin glass in semiconductor packaging may actually be a very good idea, even though its optical properties and flexibility are irrelevant in this application.

The Role of Glass in Interposers

For many years the semiconductor packaging industry has been developing packages that are smaller, thinner, and lighter than what has come before. Ultrathin glass, 30 to 100 μm, may be able to further progress toward this goal.

The target application is 2.5D or 3D multi-chip or chip scale packages (CSP), where semiconductor chips are placed in close proximity or stacked on top of each other to provide a space-saving configuration. Such packages traditionally use a layer of thinned silicon as an interposer to connect chips to each other and to the underlying organic substrate. Silicon has the advantage of being a familiar material with a well-established infrastructure in the semiconductor packaging industry, but it does have some drawbacks, the major one being cost.

Glass may be preferable to silicon as an interposer because it is a less expensive material, it can be provided in thin sheets (silicon has to be ground and polished to the proper thickness) and it is thermally insulating. Silicon is a semiconductor, not an electrical insulator, which can cause problems with crosstalk between chips.

Silicon conducts heat better than glass, making the semiconductor industry a bit suspicious of the ability of glass to conduct heat sufficiently to avoid hot spots in sensitive ICs. The answer is in the through-glass vias (TGV), channels drilled through the interposer that are filled with metal (usually copper) and form electrical connections between the chip and the organic substrate. Solid filled vias act like heat pipes to provide a path for heat conduction.

The potential cost advantages of glass can best be achieved using large sheets of glass, thus allowing facilities to process more units in parallel than is possible with silicon wafers. The largest possible cost savings of using flexible glass is realized if it can be integrated into a roll-to-roll production process. Several suppliers are producing flexible glass on rolls, but the semiconductor industry is not necessarily prepared to process it.

Re-evaluating the Supply Chain

While glass may be a compelling interposer material from the point of view of glass makers, lack of infrastructure in this application is a real problem. In order for glass to be useful as an interposer, someone needs to drill vias through the glass and metallize them, and it is not yet clear who that would be. Several industries could participate in the supply chain, but there are barriers in all cases:

Semiconductor packaging houses: This industry is not used to working with glass and is not inclined to do so. It is very resistant to change and may be especially averse to implementing R2R processing. Convincing semiconductor packaging facilities to process glass will clearly be an uphill battle.

Flat-panel display manufacturers: These companies have experience with glass but have not historically had anything to do with semiconductor packaging. It may be possible to build awareness in this sector, but the flat panel display industry prefers to sell large pieces of glass.

Printed circuit board manufacturers: The PCB industry currently makes organic interposers, geared toward applications where fine pitch is not required. Glass suppliers might be able to work with the PCB industry, which is used to large panels, if they want to supply sheets of glass. It still may be difficult, however, to implement very thin glass using this approach. It also will probably be difficult to integrate TGV production into a PCB-like process flow.

Organizations that are promoting ultrathin glass interposers are attempting to address the infrastructure challenge:

Georgia Tech: The Packaging Resource Center (PRC) at Georgia Tech has been working with industry partners on glass interposers since 2010 and has moved from initial trials with 180-μm thick glass down to the thinnest products that today’s glass suppliers are producing. The PRC is working with major glass suppliers such as Corning and Schott, who are interested in flexible glass interposers.

The PRC has been working on transferring the technology from prototype to low volume, and perhaps eventually high volume, commercial production. It has made some real progress in developing the technology and moving prototyping from labs into industry, but admits that the greatest challenge in moving forward is lack of infrastructure to support the transition.

Triton: Triton Micro Technologies, a subsidiary of nMode solutions that is partially funded by Asahi Glass Company, is providing some missing segments in the supply chain. Triton has developed a production process to create through glass vias (TGVs) that is sufficient for today’s 2.5D applications and it is making interposers for MEMS, RF, and optics at its manufacturing facility in Carlsbad, CA. According to Triton, the major advantage it provides over silicon is the ability to produce solid filled, hermetic TGVs.

Existing commercial products use glass interposers from Triton, but this is much thicker glass, typically 0.3 mm or greater. The glass is cut into wafers, matching the form factor of silicon but not requiring backgrinding. This provides the convenience of a process that fits easily into existing manufacturing lines but doesn’t take advantage of glass’ potential to provide thinner interposers at much lower cost than silicon. Triton can make large panels of 0.1-mm glass with TGVs, but customers do not know how to handle it and may not be inclined to learn.

NanoMarkets understands the potential advantage thin glass would have as an interposer, but is not especially optimistic about its future, especially in the near term. It seems very unlikely that flexible glass will be able to generate large revenues in this space, even if penetration rates get large. Each product uses a very small amount of glass compared to what would be needed for even a smart phone display.

The semiconductor packaging industry may be an even more difficult environment for introducing new processes than the display industry, and we know flexible glass has had challenges there. Still, we feel this sector is worth keeping an eye on to see if glass has an opportunity to succeed where silicon has not.

See More: http://nanomarkets.net/market_reports/report/flexible-glass-markets-2014-and-beyond

“Connecting” The Dots – New Nanotechs Team Up for Displays & SS Lighting


Connecting the Dots

Connecting the Dots image1By combining carbon dots that emit blue light and zinc copper indium sulphide quantum dots that emit in the green and red regions of the electromagnetic spectrum, researchers in China and the US have succeeded in making white light-emitting diodes with a high colour-rendering index of 93. The devices might find use in solid-state lighting and displays.

Lighting consumes around 20% of all globally generated electrical energy. Light-emitting diodes (LEDs), and especially white LEDs (WLEDs), could help reduce this figure.

At present, most WLEDs contain the YAG:Ce yellow phosphor, but this type of LED has a low colour-rendering index (CRI) because it only weakly emits in the red spectral region. Replacing YAG:Ce with semiconducting quantum dots (QDs) might be one way to overcome this problem, if it were not for the fact that most high quality QDs contain cadmium or lead, which are highly toxic.

Researchers have recently suggested using carbon dots (CDs), not only as more environmentally friendly alternatives, but also because they absorb light over a broad range of light wavelengths. However, there is another problem here in that these materials generate rather “cold” light, which is not very comforting. This is because they do not emit much light in the yellow and red regions.

Connecting the Dots image1

CD – QD WLED’s

Making cold light warmer

Although scientists have already overcome this drawback by combining these blue-emitting CDs with multi-colored QD phosphors to increase the CRI, such phosphors are still based on cadmium. So the problem has annoyingly come full circle.

A team led by Andrey Rogach of City University in Hong Kong and William Yu and Yu Zhang of Jilin University is now saying that it has found a way around this issue once and for all.

The researchers have fabricated WLEDs by combining carbon dots that emit blue light with yellow- and red-emitting Cd-free zinc copper indium sulphide core/shell QDs. The devices, which were made by mixing suitable quantities of the two types of material with the polymer PMMA on the surface of a blue LED chip, have a very high CRI of 93. This value is higher than the CRI (of less than 75) of the best YAG:Ce commercial WLED.

Emitting over a broad range of light wavelengths

“The high CRI in our WLEDs comes thanks to the fact that the ZnCuInS QDs emit over a broad range of light wavelengths,” explains Zhang. “The devices show promise for use in solid-state lighting and displays.”

The team, which includes researchers from Louisiana State University, says that it is now focusing on the structure and surface of its devices to further improve their efficiency.

“We are also trying to make the LEDs emit different colours by tuning the nanoparticle size, the thickness and number of emitting layers” Zhang tells nanotechweb.org. “Some of our recent work has already been published in Appl. Phys. Lett., ACS Nano and Phys. Chem. Lett., for example.”