Chementator: Grätzel cell  

Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE; Freiburg, Germany; edlinks.chemengonline.com/7370-575) have developed a solar-cell prototype that is semi-transparent, color-tunable and (thus far) resistant to weather degradation. A "classical Grätzel cell" according to Andreas Gombert head of Fraunhofer’s Materials Research and Applied Optics department, the prototype is composed of the expected TiO2 nanoparticles, Ru dyes and an iodide-triiodide redox pair — all sandwiched between two panes of glass. The module is relatively cheap to manufacture, but not competitive with crystalline silicon solar modules due to its 4% efficiency. Amber in color and feasibly available with printed images, the prototype is instead being developed as a decorative, energy-collecting construction-material. The researchers surmounted a persistent obstacle to outdoor use by substituting a heat-fused glass frit for the polymeric glue conventionally applied to protect the sensitive organic dyes from contact with air. "We have been testing our modules outdoors since the middle of last year," Gombert says pointing out that they have thus far survived the full gamut of weather conditions. Though, "assessment…