Copper Nanoparticle Inks and Applied Nanotech

As to copper inks (which I understand will be Applied Nanotech's future, making and salvation) I can find nothing in the literature about it, the Japanese partner or what is so valuable.

I did find this:
Nanosolar:
What is claimed is:
1. A method for fabricating coated nanoparticles, comprising the steps of: obtaining core nanoparticles containing one or more elements from group IB and/or IIIA and/or VIA and coating the core nanoparticles with one or more layers of metal from group IB, IIIA or an element from group VIA in a controlled fashion such that the resulting coated nanoparticles have a desired stoichiometric ratio of elements, wherein the core nanoparticles contain copper.
Source

And this - the Holy Grail - printing ICs:
The holy grail is a copper based ink, which has been available for some time, but not used because in the cure process the copper oxide layer that forms on the surface is not conductive. This then makes it difficult to achieve a good connection with the other components, and it is so unreliable that silver had been preferred as overall it offers better yield and reliability due to the interconnections involved.
Source

The cure processes:
1)
However, the Novacentrix PulseForge cures the copper ink so quickly that it does not have time for an oxide layer to form.
http://www.novacentrix.com/products/photonic.php

2)
M3D - Optomec another APNT cohort using a laser to sinter the copper:
Maskless Mesoscale Material Deposition (M3D) System
http://www.novacentrix.com/images/Characterization%20of%20Soft%20Magnetic%20Nano-Material%20Deposited%20with%20M3D%20Technology%20-%20ppt.pdf

And Cima NanoTech:
Technology Pioneer 2008 - Jon Brodd (Cima Nanotech)

YouTube Video:
http://www.youtube.com/watch?v=Rqnf9foDdi0

Interesting!

A competitor?

Ref:
Nano Materials in Printed Electronics: Bill Faulkner1; 1Cima Nanotech
The Global Electronics Industry is seeking next generation manufacturing methods to produce cheaper, smaller, and more flexible components. Industry leaders are ramping up significant development projects to eliminate the high capital costs, expensive processing, and environmentally damaging lithographic etching of electronics. Functionalized nano-materials are emerging a key component to meeting these goals. Printing technologies such as ink jet, gravure, flexo, and other graphic arts based systems are being optimized to achieve the higher resolution and operational demands of electronics. In many cases, the unique properties of nano materials are the necessary components in inks and coatings for these systems. The multi-billion dollar market opportunity includes components for flat panel displays, EMI shielding films, solar cells, printed thin film transistors, and RFID tags.Cima NanoTech is manufacturing & commercializing nano metal-based coatings and inks that enable self-assembling random patterns and direct printing of electronic circuits and films. The venture capital backed company is headquartered in St. Paul, Minnesota with R&D facilities in Caesarea, Israel, and toll manufacturing in Japan.
http://www.tms.org/Meetings/Specialty/nano06/PrelimTechProg.pdf

Cima NanoTech:
http://www.cimananotech.com/

NovaReady:
APNT is a customer of theirs for copper nanoparticles.

Japanese chemical cohort:
Unknown name.

All very interesting and VERY frustrating cause I have no idea whatsoever where APNT fits in and what they bring to the table.

Nanosolar Printing Video

Nanosolar's proprietary nanoparticle ink.

Here comes the sun

Posted: June 23, 2008, 9:15 PM by Chris Boutet

Nanosolar’s breakthrough technology is 10 times more powerful than a nuclear reactor and cheaper, too

By Lawrence Solomon

Go to YouTube and you can see a corporate video of a printing press running at 100 feet per minute, applying a nanoparticle ink to foil and producing solar cells. This machine is owned by Nanosolar Inc., which in turn is partly owned by Sergey Brin and Larry Page, the founders of Google. This one printing machine, Nanosolar claims, can produce solar cells with a capacity of 1,000 MW per year, the equivalent of a nuclear reactat Indian Point outside Manhattan or two nuclear reactors at Pickering outside Toronto.

Unlike nuclear reactors, which take a decade to build and billions of dollars in capital costs before delivering a single kilowatt-hour to a home or business, Nanosolar’s breakthrough technology can help meet society’s power needs soon after its ink has dried, and the press’s capital costs amount to a mere $1.65-million. Put another way, we can wait 10 years to get nuclear power up and running. Or, by relying on a single Nanosolar press, we can have the solar equivalent of a major nuclear plant in one year, and the equivalent of 10 major plants in a decade. Soon, says Nanosolar, its printing presses will be operating much faster — perhaps 20 times faster. Should this prove feasible, a single Nanosolar press would pump out in a single decade the equivalent of 200 nuclear plants — far more than now exist in all of North America.

To add to the slam-dunk superiority of Nanosolar-type technology over nuclear, solar cells produce power when we especially need it — when people are awake and industries are humming. During the low-value off-peak hours when power is in great surplus, the solar cells sleep, too. Nuclear reactors, by contrast, can’t ratchet down or turn off when their output isn’t needed. Off-peak nuclear power, in fact, is sometimes produced at a loss because its operating costs exceeds the pittance earned at, say, 3 a.m.

To get bang for the buck, and obtain the power that a growing economy needs, nuclear and solar are as different as night and day. Nuclear power, a half-century after the launch of the first generation of nuclear reactors, remains an immature technology, each successive generation proving to be not only unreliable but also subject to ever-higher costs. Solar technology, in contrast, becomes ever more reliable and ever less costly, and is only immature in the same way that computer technology is immature — there is no end in sight yet to how far and fast it can go.

Nanosolar, founded in 2002 by two Stanford PhD candidates applying Silicon Valley smarts, is a case in point. By the end of 2003, it had obtained 60 patents, By 2004, it had developed its printing method. By 2006, it had published its results in a peer-reviewed journal and, within months, raised $100-million. By the end of 2007 it had made its first commercial shipment. Now Nanosolar can’t keep up with the demand — its factory’s output for the next 12-months is pre-sold.

Nanosolar’s solar panels could go on rooftops but the company recommends against this — at least until building codes become flexible enough to accommodate panels without the need to battle municipal bureaucracies. Besides, it says, it is developing a residential product sure to wow the homeowner.

In the meantime, it touts small municipal solar power plants that can be up and running in one year on the outskirts of cities and towns, where land is readily available. Each would be between 2 MW and 10 MW in size — enough to power 1,000 to 5,000 homes. Put one of these in several hundred cities and a nuclear plant’s worth of power would be delivered, locally and in a decentralized manner, and without the expensive and unsightly transmission towers that accompany large nuclear plants.

As impressive as Nanosolar is, here’s something more impressive still: This company is but one of several with solar breakthroughs that stand to revolutionize the energy world. Some of the competing solar technologies are designed for large-scale applications, some small. In this dynamic new energy marketplace, some will prosper and, doubtless, some will fail, just as many of the computer pioneers in the 1970s and 1980s failed for one reason or another. But large or small, well capitalized or not, the solar technologies are working more impressively than anyone could have dreamed a decade ago and seem certain to overtake nuclear as a provider of additional power to our electricity systems. If the projections from Nanosolar and others prove accurate, in fact, they will become the most economic power source of all, besting even coal.

Clean, limitless power is now within grasp, courtesy of those who have reached for the sun.

Financial Post
LawrenceSolomon@nextcity.com

Lawrence Solomon is executive director of Energy Probe and author of The Deniers. This is the first in a series on renewable energy.

Source

Innovalight's Silicon Ink

May 14, 2008

by Joe Kwiatkowski, Physicist, Imperial College London

London, UK [RenewableEnergyWorld.com]

The last quarter of 2007 was an exciting time for the Silicon Valley start-up Innovalight: first a successful finance round that drew US $28 million of new capital, then the accolade of being amongst Red Herring's top one hundred innovators. Why the interest in Innovalight? Because of its remarkable claim to be able to print thin-film silicon solar cells.

Printing is generally a low-cost and high throughput process, in stark contrast to conventional methods used to produce amorphous and crystalline silicon solar cells. As such, Innovalight claims it will be able to substantially reduce the cost of photovoltaics. In a recent interview, CEO Conrad Burke predicted cells may eventually be sold for US $1 per watt — a figure perhaps determined less by technological considerations and more by similar claims made by his neighbors like Nanosolar.

Although details remain tightly guarded secrets, the essential element of Innovalight's process is an ink made of silicon nanocrystals. These nanoparticles can be made in a variety of ways, for example by assembling a group of molecules that contain silicon and then burning off everything except the silicon.

A patent filed in 2005 suggests that Innovalight is using a "radiofrequency plasma" to make its nanoparticles. By blasting silicon rich molecules with an electromagnetic field (at a radio frequency) it is possible to generate a gas in which some of the molecules have lost an electrical charge. Whilst charged, the molecules are extremely reactive and, with a bit of careful chemistry, can be coerced into forming nanoparticles.

By suspending these nanoparticles in a solvent to make an ink, Innovalight can then print silicon films. However, as printed, the nanoparticles are not interconnected and so the film has a high electrical resistance. To lower the resistance, the nanoparticles have to be joined by heating them until their edges are melted, at which point neighboring particles can fuse. The melting point of bulk silicon is over 1400º C and the cost of heating is a substantial cost in the production of crystalline silicon solar cells. However, a fortunate advantage of using smaller particles is that they have lower melting temperatures. Purposefully vague in their descriptions, Innovalight says only that it uses temperatures between 300 and 900º C, (possibly at high pressure and for times that could be anywhere between 5 minutes and 10 hours). Whatever the exact details, the company evidently hopes that a low-temperature printing process could offer substantial savings over conventional silicon solar cells.

It is still unclear what efficiencies Innovalight will achieve. Presumably, because it is working with thin-film solar cells, its silicon is substantially amorphous and would therefore have stabilized efficiencies of about 10%. Whatever the efficiency, and despite the difficulties that are inevitable in developing a new technology, an advantage of Innovalight's manufacturing process is that there is a wonderful number of variables that can be adjusted to get the most out of the cells. For example, nanoparticles can be grown in a variety of shapes and sizes or different nanoparticles can be mixed to determine the exact properties of the printed cell. Or, by adding germanium and tin nanoparticles to the ink, the light absorption properties can be tuned; by printing successive layers with different absorption properties, tandem solar cells could be built that would allow higher efficiencies to be reached.

Though it is probable that Innovalight will have to compromise on cell efficiency in order maintain low costs, it has come up with a phenomenon that might just help make up for its losses. According to a recent paper published in collaboration with the National Renewable Energy Laboratory (NREL), "multiple exciton generation" has been measured in Innovalight's silicon nanoparticles. What this means is that the nanoparticles might be able to produce more electrical charges than would normally be expected from a given amount of sunlight. Without this effect, the highest efficiency that a standard solar cell could ever achieve is 31%; anything else is thermodynamically impossible. However, with multiple exciton generation, the thermodynamic limit is boosted to 44%. If Innovalight could take advantage of this phenomenon it might be able to match, or even exceed, the efficiencies of conventional silicon technologies.

With its new funds Innovalight plans to construct a 3000 square meter manufacturing facility in California, and to triple its workforce over the next year. Although there is no official date on the company's website for the start of production, 2009 has been suggested elsewhere. Until then, all we can hope for from Innovalight's printers are more announcements of funds and awards.

Joe Kwiatkowski is a physicist at Imperial College London, where he works on organic photovoltaics. His current interest is the development of computational methods that can aid the design and optimization of new photovoltaic materials.

Source