A $1.2 million grant from the U.S. Department of Energy’s SunShot Initiative will help researchers at Sandia National Laboratories develop materials that could make solar power cost-competitive with other sources of energy. The work builds on Sandia’s recent successes with metal-organic framework (MOF) materials by combining them with dye-sensitized solar cells (DSSCs). MOFs will enable precise control of dyes, the researchers said, and could also facilitate electron flow. “A lot of people are working with DSSCs, but we think our expertise with MOFs gives us a tool that others don’t have,” said Sandia materials scientist Dr. Erik Spoerke. Sandia National Laboratories researcher Vitalie Stavila inserts a substrate patterned with electrodes into a temperature-controlled liquid-phase reactor for depositing MOF thin films. Courtesy of Dino Vournas/Sandia. DSSCs use dyes designed to efficiently absorb light in the solar spectrum. The dye is mated with a semiconductor, typically TiO2, that facilitates conversion of the energy in the optically excited dye into usable electrical current. They can capture more of the sun’s energy than silicon-based solar cells by using varied or multiple dyes, as well as different molecular systems. But DSSCs also have drawbacks, including dye aggregation, which decreases efficiency. Sandia senior scientist Dr. Mark Allendorf said researchers hope to use the ordered structure and versatile chemistry of MOFs to help the dyes in DSSCs absorb even more solar light. “Our hypothesis is that we can put a thin layer of MOF on top of the titanium dioxide, thus enabling us to order the dye in exactly the way we want it,” Allendorf said. A second dye, which would absorb additional parts of the solar spectrum that are not covered by the initial dye, can be inserted into the pores of the MOF. The project also includes researchers at the University of Colorado Boulder. For more information, visit www.sandia.gov.