A theoretical study of the structural and electronic properties of CdSe/CdS and CdS/CdSe core/shell nanoparticles

We present a theoretical study of the structural and electronic properties of CdSe/CdS and CdS/CdSe core/shell nanoparticles. We have considered relaxed structures of essentially spherical parts of the zincblende crystal structure. The electronic properties and the total energy were calculated using a parameterized density-functional tight-binding method. The results depend critically on the size of core and shell, and only in one case we find a charge separation upon excitation. We finally investigate the energetics related to the interchange of a S and a Se atom between core and shell.