New Stable And High-efficiency Solar Cells Developed

[OKIsItJustMe]

http://www.sciencedaily.com/releases/2008/01/080109094341.htm

New Stable And High-efficiency Solar Cells Developed

ScienceDaily (Jan. 9, 2008) — Solar cells have attracted global attention as one of the cornerstones of alternative energy. In theory, it seems to make abundant sense to tap into the energy of the sun to convert light to electricity with little or no emission of noxious pollutants. However, in practical terms, progress has been slow because of technological impediments and the many different factors that need to be optimized to obtain stable and high-efficiency devices.

Dye-sensitized solar cells based on dye molecules adsorbed onto titanium dioxide electrodes have emerged as one of the most attractive solar-cell constructs, combining low cost and relative ease of fabrication with high-efficiency performance. Indeed, state-of-the-art solar cells with this architecture show greater than 11% light-conversion efficiency. However, the catch is that these high-efficiency solar cells typically use volatile organic solvents as electrolytes, which essentially precludes their use in outdoor applications because of the high vapor pressure of the solvents.

Solvent-free solar cells fabricated so far show poor performance owing to the high viscosity of the alternative electrolytes. Now, a team of researchers at the Ecole Polytechnique Fédérale de Lausanne in Switzerland have fabricated a solvent-free dye-sensitized solar cell based on a binary ionic liquid electrolyte. These devices show a light-conversion efficiency of 7.6% under simulated sunlight conditions, which sets a new record for a solvent-free device.

Shaik Zakeeruddin, Michael Grätzel, and their colleagues have used a mixture of two ionic liquids as the redox electrolyte in conjunction with a novel highly conjugated ruthenium-based dye to prepare a solvent-free solar cell. Ionic liquids essentially have a vapor pressure of zero, which makes them preferable even to robust and low-volatile organic solvents. However, the typically high viscosities of ionic liquids and the fact that most of the promising ionic liquids are composed of iodide ions have precluded their application in viable cells since iodide ions tend to have a deleterious impact upon the photoconversion efficiency by quenching the dye sensitizer.

...

[fascisthunter]

1. I Have Watched a Program Explaining This Technology on the Science Channel

looks promising. I hope it works out.