Sunday, February 07, 2010

Recharging your cellphone, mother nature’s way

A new solar cell that imitates Mother Nature’s way of converting sunlight to energy is making its debut in a variety of consumer products. The technology uses a photosensitive dye to start its energy production, much the way leaves use chlorophyll to begin photosynthesis.

The dye-sensitized cells will be used to provide power for devices ranging from e-book readers to cellphones — and will take some interesting forms. For e-book readers, for example, the cells may be found in thin, flexible panels stitched into the reader’s cover. But such panels will also be housed in new lines of backpacks and sports bags, where they can recharge devices like cellphones and music players.

The technology, long in development, will work best in full, direct sunshine, said Dr. Michael Grätzel, a chemist and professor at the École Polytechnique Fédérale de Lausanne in Switzerland. But the cells will also make good use of dappled and ambient light, including the indoor light of fluorescent bulbs, he said.

Most photovoltaic cells are based on silicon or related inorganic materials, not dyes. Dr. Grätzel and an American colleague, Brian O’Regan, first reported on the new type of cell in the journal Nature in 1991, and Dr. Grätzel said that he and other colleagues had been working since then to refine the technology.