New Solar Technology from Ancient Diatoms

Scientists are constantly working on alternative energy sources to make its use widespread like fossil fuels. They are tirelessly working on the drawbacks of alternative energy sources so that they can be all pervasive like traditional sources of energy. Engineers at Oregon State University have found out a method to use an ancient life form to create one of the newest technologies for solar energy. These life forms can be successfully incorporated into the solar devices. Oregon State University’s (OSU) researchers are using the diatoms for furthering new technology in solar energy. Diatoms are small, unicellular marine life forms. They have inhabited the oceans for at least 100 million years. Diatoms are considered the basis for much of the life in the oceans. Their unique property is they have rigid shells that can be used to create order in a natural way at the extraordinarily small level of nanotechnology. Greg Rorrer who is an OSU professor of chemical engineering explained, “Most existing solar cell technology is based on silicon and is nearing the limits of what we may be able to accomplish with that. There’s an enormous opportunity to develop different types of solar energy technologies, and it’s likely that several forms will ultimately all find uses, depending on the situation.” Here the research team is using biology instead of usual traditional semiconductor devices for the betterment in solar technology. Scientists at OSU and Portland State University have devised a new method to make “dye-sensitized” solar cells. Here photons bounce around like they were in a pinball machine, striking these dyes and producing electricity. Rorrer said, “Dye-sensitized solar cells already exist. What’s different in our approach are the steps we take to make these devices, and the potential improvements they offer.” One can argue that this technology is expensive compared to current available ones. It can be countered by saying that this technology is “slightly” more expensive but dye-sensitized solar cells can potentially triple the electrical output. Dye-sensitized technology is environmentally friendly. This technology also performs well under lower light conditions. This new technology is also making manufacturing process simple and effective. The greatest advantage of the diatoms is they already have shells with nanostructures required for solar technology. They are permitted to settle down on a conductive glass surface. After the completion of this step the living material is removed and what is left are tiny skeletons of the diatoms forming templates. The team has then utilized a biological agent to precipitate soluble titanium into very tiny “nanoparticles” of titanium dioxide. This titanium dioxide develops a thin film operating as the semiconductor for the dye-sensitized solar cell device. So these biological materials make the manufacturing process simple. As Rorrer himself explained, “Conventional thin-film, photo-synthesizing dyes also take photons from sunlight and transfer it to titanium dioxide, creating electricity. But in this system the photons bounce around more insidethe pores of the diatom shell, making it more efficient.” ((23 APR 2009))









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