Simple one-dimensional quantum models of electron injection from excited photosensitizer molecules to semiconductor nanoparticles and of further electron motion through the TiO2 nanoparticle are considered. It was found that essential parameters of the models may correspond well to the real values of spatial and energetic parameters of ruthenium sensitizer complexes absorbed on the TiO2 surface. (C) 2002 Elsevier Science B.V. All rights reserved.