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Michael Grätzel's Solar Cells Get Stylish With Color and Translucent Materials


Jun 18, 2010

By Ariel Schwartz

Read More: http://www.fastcompany.com/1661787/michael-graetzel

Michael Grätzel may be the closest thing to a living legend in the solar energy world. A professor at École Polytechnique Fédérale de Lausanne, the Swiss scientist discovered a new type of thin-film solar cell--dubbed the dye-sensitized solar cell (aka the Grätzel cell)--in 1991. Now, nearly two decades later, Grätzel's invention is taking off, with companies like Konarka, Hydrogen Solar, and Sony developing the cells for commercial use.

Grätzel's cells, which are inspired by the photosynthetic process, consist of a porous layer of titanium dioxide nanoparticles covered with a sunlight-absorbing molecular dye. The cells currently have a lower efficiency than single crystal silicon cells, and Grätzel's technology offers a number of advantages. In a traditional silicon solar cell, the silicon acts as both a source of photoelectronics and an electric field. But in a dye-sensitized solar cell, the semiconductor is only used for transport, while the photoelectrons come from a separate photosensitive dye. As more research yields higher-efficiency Grätzel cells, companies need only switch out their dyes--the rest of the production process stays the same.

Dye-sensitized solar cells have another distinct advantage: The dyes can be manufactured in an array of colors. The Sunny Memories project, featured earlier this month at New York's Center for Architecture, exploited this feature with colorful solar designs. Grätzel's cells can also be made translucent--a first in the solar industry. "In this respect they have a unique application, like for electric power-producing windows and glass facades," he says.