Technical Feature

Technical Feature

Dye-Sensitized Solid-State Heterojunction Solar Cells

Michael Grätzel


The dye-sensitized solar cell (DSSC) provides a technically and economically viable alternative concept to present-day p–n junction photovoltaic devices. In contrast to conventional silicon systems, where the semiconductor assumes both the task of light absorption and charge carrier transport, these two functions are separated in DSSCs. The use of sensitizers having a broad absorption band in conjunction with wide-bandgap semiconductor films of mesoporous or nanocrystalline morphology permits harvesting a large fraction of sunlight. There are good prospects that these devices can attain the conversion efficiency of liquid-electrolyte-based dye-sensitized solar cells, which currently stands at 11%. In this article, we present the current state of the field, the realm of our review being restricted to the discussion of organic molecular hole conductors, which have demonstrated the best performance to date.


  • dye-sensitized solar cells;
  • mesoscopic junctions;
  • solid-state heterojunctions.

Michael Grätzel is a professor at the Swiss Federal Institute of Technology in Lausanne, where he directs the Laboratory of Photonics and Interfaces, and he is a part-time distinguished visiting professor at the Delft University of Technology. He has pioneered research on nanomaterials and display-related applications, and he developed a new type of solar cell based on dyesensitized mesoscopic oxide particles.

Grätzel is the author of more than 500 publications, two books, and over 40 patents. He has been an invited professor at the University of California at Berkeley, the University of Tokyo, and the Ecole National Supérieur de Paris. He has received numerous awards, including the Millennium 2000 European innovation price, the 2001 Faraday Medal from the British Royal Society, the 2001 Dutch Havinga Award, the 2003 Italgas Prize, and McKinsey Venture Awards in 1998 and 2002. He holds a doctor degree from the TU Berlin and honorary doctorates from the Universities of Uppsala and Turin.

Grätzel can be reached by e-mail at