Ionic salts could increase efficiency of dye solar cells

October 16, 2009--A group of scientists at Universidad Pablo de Olavide (UPO; Seville, Spain) headed by Juan Antonio Anta are using ionic salts to optimize the performance of a type of dye-based photovoltaic cell (Grätzel cell) that artificially mimics photosynthesis, according to a recent ScienceDaily.com story.

October 16, 2009--A group of scientists at Universidad Pablo de Olavide (UPO; Seville, Spain) headed by Juan Antonio Anta are using ionic salts to optimize the performance of a type of dye-based photovoltaic cell (Grätzel cell) that artificially mimics photosynthesis, according to a recent ScienceDaily.com story (see also "Energetic nanoparticles swing sunlight into electricity" and "Popcorn-shaped nanocrystallites double efficiency of dye-sensitized solar cells").

Grätzel cells are photovoltaic (PV) devices that take advantage of the interaction of a structured semiconductor less than a nanometer in size and an organic dye that acts as a solar collector. Elena Guillén, a member of UPO's Coloides y Celdas Solares Nanoestructuradas (Nanostructured Colloids and Solar Cells) Group, says this dye can be either synthetic or natural and can even enable the use of chlorophyll for this type of cell.

Thus, researchers at UPO have begun a study with which they hope to increase the efficiency of these eosin or mercurochrome-based organic components by incorporating less-volatile ionic salts, known as green solvents, with a view to preventing evaporation of the liquid compounds and the consequent reduction in efficiency.

Although there are already some third-generation dye PV cells on the market (for example, for recharging mobile phones), the researchers say the future of these cells lies in new market niches such as decoration or use in colored windows that not only allow light through but use this light to generate electricity.

Even though the organic cells are short-lived (lasting only as long as a year), organic materials are usually cheaper. The biggest hurdle is that maximum efficiency for dye solar cells obtained in the laboratory is only 11%, which is competitive but drops when extrapolated to an industrial scale. Ionic salts could improve this lifetime and efficiency value.

For the full story, click here.

For more information on Universidad Pablo de Olavide, go to www.upo.es.

--Posted by Gail Overton, gailo@pennwell.com; www.laserfocusworld.com.

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