Exciton dissociation and interdot transport in CdSe quantum-dot molecules - art. no. 153304

One of the most important parameters that determine the transport propertie s of a quantum dot array is the exciton dissociation energy, i.e., the ener gy DeltaE required to dissociate an exciton into an electron and a hole loc alized in different dots. We show that a pseudopotential calculation for a dot molecule, coupled with a basic configuration interaction calculation of the exciton energy levels, provides directly the exciton dissociation ener gy, including the effects of wave function overlap, screened Coulomb attrac tion between the electron and the hole in different dots, and polarization effects. We find that DeltaE decreases as the interdot distance decreases a nd as the dielectric constant of the medium increases.