Ultraviolet-visible absorption spectra and photoluminescence spectra were used to demonstrate efficient charge-carrier migration in a novel bulk heterogeneous block copolymer system. One moiety of the block copolymer was functionalized with charge-transporting carbazole groups, whereas the other block formed domains suitable for the in situ synthesis of CdS nanoclusters. The excitation of the cluster-free copolymers with 350-nm-wavelength radiation led to a strong emission peak at 450 nm that was associated with the carbazole groups. When CdS clusters were present in nearby but spatially distinct domains, the carbazole emission was completely quenched and replaced by a very broad emission in the visible range (near 560 nm). The implications of these observations are discussed in the context of the energy-transfer mechanism and possible device applications. (C) 2003 Wiley Periodicals, Inc.