Solar start-up to develop prototype for low-cost PVs

Sara Ver-Bruggen - 16 Feb 2011

Solexant in the US is to develop a prototype of a flexible thin-film solar cell based on printable nanoinks.

The California company, which owns intellectual property originally developed at the Lawrence Berkeley National Lab, has been awarded $1 million (€730,000) over 12 months by the US Department of Energy, to help finance the work on a prototype that can be scaled up for commercial production.

Copper, zinc, tin and selenide are used to make the inks for printing the cell's layers. Roll-to-roll and solution processing equipment can be used to fabricate the cells.

Simplification

The trend for processing semiconductor materials as nanoinks and printing the photoactive layers of solar cells could help the industry reduce the cost of solar, by simplifying the overall cell production process.

Compound semiconductors found in conventional thin-film technologies, but processed as nanoinks, can be deposited at low temperature. Ffabrication of flexible substrates allows for production to occur on high-volume, roll-to-roll production equipment.

Elsewhere in the US chemists at The University of Texas at Austin have succeeded in spray-coating copper indium diselenide (CIS) nanoink solar cells on plastic substrates. Conversion efficiencies are low, but the technology negates the need for a high-temperature post-deposition annealing step in the production process.

Nanoink solar

Nanosolar is pioneering the use of nanoinks to exploit the economics of roll-to-roll production in the photovoltaics industry. The US company, founded in 2002, has plants in California and Berlin, and its panels are being used in renewable energy installations in Germany.