School of Natural Sciences and Mathematics

Light and Energy, Conversion of Sunlight to Electricity by Dye Sensitized Solar Cells

Presented by Michael Graetzel, PhD, Professor at the Ecole Polytechnique de Lausanne.

August 18, 2006 @ 3 p.m.
TI Auditorium (ECSS 2.102)

Dr. Graetzel directs the Laboratory of Photonics and Interfaces. He initiated research on energy and electron transfer reactions in mesoscopic-materials and their optoelectronic applications.

He discovered a new type of solar cell based on dye sensitized mesoscopic oxide particles and pioneered the use of nanomaterials in electroluminescent and electrochromic displays. Author of over 500 publications, two books and inventor or co-inventor of over 40 patents, his scientific work received over 30000 citations ranking him amongst the most highly cited scientist in the world. He has received numerous honors and awards including the Millennium 2000 European innovation price, the 2001 Faraday Medal of the British Royal Society, the 2001 Dutch Havinga Award, the 2002 IBC International award in Supramolecular Chemistry and Technology, the 2004 Italgas Price, two McKinsey Venture awards in 1998 and 2002 and the 2005 Gerischer Prize.

Learning from the concepts used by green plants he and his colleagues have developed a molecular photovoltaic device whose overall efficiency for solar energy conversion to electricity has already attained over 11%. The system is based on the sensitization of nanocrystalline oxide films by a molecular dye [1,2]. The underlying fundamental processes of light trapping by the sensitizer, heterogeneous electron transfer from the electronically excited chromophore into the conduction band of the semiconductor oxide and the percolative migration of the injected electrons through the mesoporous film to the collector electrode will be analyzed in his lecture. The low cost and ease of production of the new cell should benefit large-scale applications. Impressive stability both under long-term light soaking and high temperature stress has been reached fostering first industrial applications. These systems will promote the acceptance of renewable energy technologies, not least by setting new standards of convenience and economy. The newly developed dye sensitized solar cells have meanwhile been found to be also useful in tandem cells for the cleavage of water into hydrogen and oxygen by sunlight.

Sponsored by the School of Natural Sciences & Mathematics, the Dept. of Physics, and the Office of the VP for Research

For more information, please contact Beth Keithly.

  • Updated: December 19, 2007