Feb 2, 2006
Start-up targets thin-film silicon solar cells
InnovaLight of the US is a start-up with big ambitions when it comes to photovoltaics. As the cost of solar cells based on crystalline or bulk silicon continues to rise, InnovaLight says its silicon nanocrystal technology not only offers cost savings when it comes to manufacturing but some unique optical advantages as well.
"We have worked diligently on developing silicon quantum dots [nanocrystals] and have successfully been able to do that," company president Conrad Burke told Optics.org. "We can now produce them in volume and solution-process them."
According to Burke, the ability to solution-process the dots in a so-called silicon ink could lead to cheaper manufacturing. "You now have the potential to produce thin-film photocells which lends itself to high-throughput manufacturing using existing roll-to-roll printing technology," he said. "Our modelling indicates that there will be substantial improvements in cost versus how silicon is used today."
Solution-processing also means that InnovaLight can deposit its silicon nanocrystals onto flexible substrates. This opens up a vast array of markets from consumer applications such as clothing to charge up portable electronics through to flexible battery chargers for the military.
Burke says that the company can produce silicon quantum dots in uniform sizes from 2 to 10 nm in diameter. By controlling these sizes, the company can tailor the optical properties of the dot, such as its absorption spectra.
"You can tune the photovoltaic to capture parts of the spectrum that have not efficiently been captured before with traditional methods - the red and the infrared for example," said Burke.
While InnovaLight is fully focused on offering photovoltaic products, and Burke expects this to happen in 2007, it has also exploited its technology to produce tunable silicon emitters.
"Silicon in its bulk format we all know is not an efficient emitter but when you get down to the quantum-confined sizes, you get very different effects," said Burke. "For the smaller sized particles you can get blue emission and for the larger particles you can get red emission. By having a film of these devices, you can electrically stimulate them."
If InnovaLight's achievements so far are anything to go by, then 2007 could be an interesting year for the photovoltaic arena.
• InnovaLight was founded in 2001 based on technology being developed at the University of Texas at Austin. Since then it has received seed funding and has also completed a series A funding round, although Burke would not disclose the sums involved. The company has also won grants from the US Department of Energy and the National Science Foundation. It was also named a Technology Pioneer for 2006 by the World Economic Forum.
About the author
Jacqueline Hewett is technology editor on Optics.org and Opto & Laser Europe magazine.