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. Also called photovoltaic cells, solar cells convert sunlight directly into electricity and are typically made from silicon, although other materials that are flexible are gaining steam. Solar panels used to power homes and businesses each consist of 40 or so of these cells, according to the National Renewable Energy Laboratory. 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 […]