Transparent solar cells based on dye‐sensitized nanocrystalline semiconductors

Low‐cost dye‐sensitized solar cells have attracted much attention because of their unique characteristics of transparency and various colors. A dye‐sensitized solar cell is composed of a dye‐coated nanocrystalline wide‐bandgap semiconductor, redox electrolyte and platinum counter‐electrode. Transparency and various colors are attributed to a 10–20 μm thick semiconductor film with particle size of about 10–20 nm and a difference in HOMO–LUMO energies of the dye molecules, respectively. A biomimetic working principle enables effective electron injection and regeneration. Recent research on dye‐sensitized solar cells has been focused on the improvement of solar‐to‐electricity conversion efficiency as well as long‐term stability. In this report, the recent advances of transparent solar cells based on dye‐sensitized semiconductors are reviewed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)