Electron states in CdMnSe/ZnSe and in CdSe/ZnMnSe diluted magnetic semiconductor quantum dots

摘要

Self-assembed quantum dots (QDs) based on Ⅱ-Ⅵ compounds are interesting with regard to their electronic and optical properties due to their large scale provided by their fundamental gap. Among Ⅱ-Ⅵ materials, diluted magnetic semiconductor (DMS) nanostructures like CdSe/ZnMnSe and CdMnSe/ZnSe QDs are of particular interest due to the exchange interaction between the spin of the carriers and the spin of the paramagnetic Mn~(2+) ions located in ternary alloyrnlayers. The application of an external magnetic field at low temperature induce the so-called giant Zeemann effect of the band edges. In this work we first report the band offset calculations for zinc blende pseudomorphically strained CdSe/ZnSe interface. Then, we calculate the lowest electron states in both (Cd,Mn)Se/ZnSe and in CdSe/(Zn,Mn)Se QDs. Results show that the giant Zeeman splitting is more important when the Mn ions are inside the dot.