Novel hybrid solar cells consisting of inorganic nanoparticles and an organic hole transport material

A novel three-layer concept for efficient solid-state solar cells is presented. The hybrid devices consist of an inorganic nanocrystalline titanium dioxide layer for electron conduction, a surface-adsorbed ruthenium dye complex for light absorption, and an organic triphenyldiamine layer for the transport of holes. External quantum efficiencies of up to 0.2% have been achieved. Time-resolved current measurements with pulsed excitation of the dye layer reveal the charge transport to be totally controlled by the nanoparticles in the long-time regime. The high charge storage capability of the porous titanium dioxide layers is demonstrated by junction-recovery measurements.