Transient photobleaching experiments have been performed with spherica
lly layered semiconductor particles consisting of a size quantized cor
e of CdS, one monolayer of HgS and three monolayers of CdS as the oute
rmost shell. The most interesting result from these experiments is tha
t the photobleaching follows spectrally the newly evolving 1s-1s elect
ronic transition of the composite particles. Some considerations conce
rning the charge carrier dynamics in the novel quantum dot quantum wel
ls (QDQWs) are outlined.