Compositional effects on the electronic structure of ZnSe S ternary quantum dots

We report first-principles density functional theory calculations of the electronic structure of ZnSeS ternary quantum dots (TQDs) and the impact of composition and compositional distribution on the electron density distribution, electronic density of states, and band gap. We find that the band gaps for ZnSe/ZnS core/shell TQDs are nearly independent of the number of S atoms in the shell, whereas the presence of S in the core of alloyed TQDs modifies the electronic energy levels significantly. Our results imply that distribution of S atoms can be used to achieve quantum confinement in different regions of the TQDs. © 2011 American Institute of Physics.