- Category: Technology
26 Aug 2009
- Published on Wednesday, 26 August 2009 06:07
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Researchers apply the nanoparticle "inks" as a spray on the solar cells. Photo by the University of Texas
The University of Texas in Austin is working on a method of producing less costly solar cells by using nanoparticle “inks” to allow for them to be printed like newspapers or even painted onto areas such as the sides of buildings or rooftops.
Brian Korgel, a chemical engineer at the university, and his team have been working on cutting the current price of solar cell manufacturing for the past two years.
They hope to cut costs to one-tenth of the current price by replacing the standard manufacturing process of solar cells—gas-phase deposition in a vacuum chamber—with their nanoparticle “inks.”
Gas-phase deposition is said to require high temperatures and is relatively expensive compared with the process being developed at the University of Texas at Austin.
"That's essentially what's needed to make solar-cell technology and photovoltaics widely adopted," Korgel said. "The sun provides a nearly unlimited energy resource, but existing solar energy harvesting technologies are prohibitively expensive and cannot compete with fossil fuels."
The inks could be printed on a roll-to-roll printing process on a plastic substrate or stainless steel. The light-absorbing nanomaterials in the inks are 10,000 times thinner than a strand of hair. These microscopic sizes allow for new physical properties that can help enable higher-efficiency.
The California-based company Innovalight was co-founded by Korgel in 2002. Innova light uses high precision inkjet manufacturing to replace many of the manufacturing steps used in solar module production today.
Initially producing inks using silicon as the basis, the team are now focusing on using copper indium gallium selenide or CIGS which costs less and is more benign in terms of environmental impact.
"CIGS has some potential advantages over silicon," Korgel said. "It's a direct band gap semiconductor, which means that you need much less material to make a solar cell, and that's one of the biggest potential advantages."
His team has developed solar-cell prototypes with efficiencies at 1%; however, they need to be at about 10%.
"If we get to 10%, then there's real potential for commercialization," Korgel said. "If it works, I think you could see it being used in three to five years."
He also said that the inks, which are semi-transparent, could help realize the prospect of having windows that double as solar cells. Korgel said his work has attracted the interest of industrial partners.