Quantum sized semiconductor particles in solution and in modified layers

The preparation of highly monodisperse, quantum-sized CdS particles is described. In these samples a band splitting into discrete exciton-like states is observed. - Quantum-sized CdS and PbS particles prepared in situ on highly porous, polycrystalline TiO2 electrodes work as highly efficient sensitizers. Photocurrent yields of more than 70% are reported. In the case of PbS it is shown that an efficient electron transfer is only possible with particles in the size quantization regime. (orig.)