Spray on Solar Cells| LiveScience.com

• Solar cells soon could be painted onto the sides of buildings or rooftops with nanoparticle inks, according to one chemical engineer.
• The new nano-ink process could replace the standard method of manufacturing solar cells, which requires high temperatures and is relatively expensive, said Brian Korgel of the University of Texas at Austin.
• “The sun provides a nearly unlimited energy resource, but existing solar energy harvesting technologies are prohibitively expensive and cannot compete with fossil fuels,” Korgel said.
• Rather than silicon, the inks developed by Korgel’s team are made up of copper indium gallium selenide (CIGS) — sunlight-absorbing nanoparticles that are 10,000 times thinner than a strand of hair.
• “We make a solution of these nanocrystals, and we spray paint them onto a substrate,” said Matthew Panthani, a doctoral student and graduate research assistant in Korgel’s lab.
• The team envisions printing such inks in a newspaper-like process. “We’d have some sort of flexible substrate, maybe plastic or metal foil, and it would be on a spool and be unrolled. And the nanocrystals would be sprayed on,” Panthani told LiveScience.