Paula Doe, SEMI -- 10/17/2006
Semiconductor International
Developers of fuel cells, solar cells and next-generation lithium ion batteries are looking to new nano-manufacturing technologies to enable their smaller and cheaper solutions to generating energy. “The real issues now in the alternative energy world,” said Ged McLean, president and CTO at Angstrom Power (North Vancouver, B.C., Canada), “are all about nano-manufacturing.”
McLean’s company is looking for ways nano-manufacturing can improve its microstructured fuel cells. High-profile thin-film solar cell suppliers Nanosolar (Palo Alto, Calif.) and Konarka Technologies (Lowell, Mass.) are counting on nanostructured materials to enable printing their low-cost thin films on flexible substrates. And Angela Belcher’s group at the Massachusetts Institute of Technology (MIT, Cambridge, Mass.) is now focusing on getting its viruses to assemble alloys for electrodes for lithium ion batteries with much higher energy density.
SEMI is bringing these and other leading nanotechnology researchers and users together with the electronics process technology supply chain at its NanoForum, Oct. 30-Nov. 2 in San Jose, to discuss manufacturing issues in nano energy, biomedical, defense and electronics markets. “I’m firmly convinced that exposing the semiconductor world to the wide range of things going on in the nanotechnology world – and vice-versa – will be a very good thing for both sides,” said Alan Rae, vice president of marketing and business development for NanoDynamics (Buffalo, N.Y.) and chair of the committee organizing the meeting. “There are lots of things you come across being applied in another area and suddenly realize, ‘Wow, I see where this can be used in my area.’”
Belcher’s group is now applying its biological self-assembly technology to making better batteries. She says her group has improved its genetic engineering in the past year to now be able to change multiple peptides on the virus’s coating – allowing them to assemble alloys instead of just single materials. “We’re able to make larger modifications now and still have it remain stable,” Belcher said.
The main focus of her work with MIT colleagues Paula Hammond and Yet-Ming Chiang is now on energy applications like battery technology, ultracapacitors and solar cells, where low-cost assembly of highly ordered material could significantly improve energy density and reduce size and weight. “I like starting with a simple system, where things don’t have to be perfectly aligned,” she said. “We’re working on a problem we think we can solve.” The current proof of concept work could lead to a working thin-film battery prototype in two years or so. Work on engineering the viruses to serve as the scaffolds for assembling III-V semiconductors like InGaN for the absorbers for solar cells is less further along, since the materials are less compatible with biological processes.
So far, the group has made a self-assembled polymer electrolyte that can be simply coated with a metal oxide anode, and it’s now working on a metal phosphate cathode coating to complete the battery. The anode is made by coating the substrate with long, thin rod-shaped viruses that are genetically engineered to bind to cobalt and gold. The viruses repel each other slightly so they arrange themselves into a tightly aligned monolayer, and coat themselves with metal ions from solution, effectively making a closely packed network of nanowires. Belcher says energy densities are 2-2.5× better than current electrode materials.
In fuel cells, performance could also be much improved, according to Angstrom Power’s McLean, by nanoscale engineering of the catalysts and their support structures. His company makes microstructured fuel cells that use an array of thin pillars of proton exchange membrane to create a large surface area for reaction. It closed on $18M in equity funding in September, and has demonstration projects from the Vancouver airport to the Royal BC Museum using its fuel cell flashlights and rechargers for standard two-way radios and PDAs.
“Catalysts are now made by bucket chemistry, and it’s impossible to know how much of the catalyst is actually being used, or how much is really needed for the reaction,” said McLean, noting that engineering catalysts on a 5-10 nm scale and manufacturing nanostructures is a huge area that’s ripe for development. “I hope a lot of people come up to me after the talk with suggestions of future R&D on how to solve some of these problems,” he added.
High-profile and well-funded solar cell ventures Konarka Technologies and Nanosolar also count on new nanomaterial technologies to print their low-temperature solar films, whether with cold sintered nano crystals of TiO2 coated with light-absorbing dye; or quantum dots, nano templates and nanoparticle ink for CIGS thin films. These low-temperature technologies could mean much of the thin-film photovoltaic market will use printing equipment, not conventional vacuum deposition tools, in coming years. In fact, market researcher NanoMarkets (Glen Allen, Va.) projects printed thin-film photovoltaics will ramp sharply over the next several years to surpass vacuum deposition in dollar value by 2012.
Directly before the NanoForum meeting, leading professors will update industry on nanoelectronics developments in the university world at Nano U, and there will be a workshop on global nano standards. For the complete agenda, see www.semi.org/nanoforum.
