A Swedish startup announced this week that it has developed an innovative technology, nanowires in liquid form, which can increase the efficiency of solar cells by up to 25 percent, enabling solar panel manufacturers to use fewer panels to generate more energy and lower costs.
Sweden-based SolVoltaics, founded in 2008, unveiled SolInk, a liquid filled with microscopic semiconductors called nanowires that are made of gallium arsenide, which can convert greater amounts of sunlight into energy than traditional solar panel materials like silicon.
Scientists have been working on tapping nanowires for photovoltaics for many years, but the challenge has always been how to fabricate nanowires economically, since gallium arsenide is very expensive to mass-produce. The other challenge has been depositing the nano material on the solar cells cheaply.
SolVoltaics has addressed both issues by coming up with a liquid form of nanowires, which it calls ink, that can be sprayed onto solar panels. A layer of polymer material is then added to keep the nanowires anchored to the solar panel.
Until now, nanowires have typically been grown as crystals on a substrate in batches, but SolVoltaics’ method eliminates substrates and uses a method called aerotaxy to grow gallium arsenide nanowires 20 to 1,000 times faster than the traditional method. Aerotaxy involves using gold as a catalyst, which combines with two other gases to form the nanowires.
The company has demonstrated how its technology works on indium phosphide solar cells, increasing their efficiency by 13.8 percent. But while indium phosphide is easier to work with, it’s not as effective as gallium arsenide in producing energy. Now SolVoltaics is using the data from indium phosphide to project that nanowires made of gallium arsenide will improve a solar cell’s efficiency by 25 percent.
Next it will need to demonstrate that on silicon solar cells. The company says the new technology can also be applied on other solar panel materials such as cadmium telluride and copper indium gallium selenide (CIGS) technology.
The startup has $11 million in funding from private investors like Industrifonden, Teknoinvest and Nano Future Invest and public funding from the European Union and the Nordic Innovation Center.
It is looking to raise $10-$20 million this year to work with an equipment manufacturer to build a pilot plant by 2015.
SolVoltaics expects it will need no more than $50 million to scale-up to a mass production roll-out in 2016, since its product is an add-on, not the whole solar panel. It will sell to solar panel manufacturers, which will pay an additional one or two cents per watt in production costs to add the nanowires, according to CEO Dave Epstein.
To read the SolVoltaics press release, click here
To read a recent article about nanowires in the journal Science, click here