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First principle study of core/shell structure quantum dots

2004; American Institute of Physics; Volume: 84; Issue: 18 Linguagem: Inglês

10.1063/1.1737470

1520-8842

Jingbo Li, Lin‐Wang Wang,

Semiconductor Quantum Structures and Devices

The electronic states of core/shell CdSe/CdS and CdSe/CdTe heterostructure quantum dots are studied by large-scale first-principles calculations. According to their natural band-offset alignments CdSe/CdS is a type-I heterostructure and CdSe/CdTe is a type-II heterostructure. We found that, the electron state changes very little, but the hole wave function in CdSe/CdS quantum dots has been localized within the core, while the hole wave function in CdSe/CdTe quantum dots is localized within the shell. The hole state in CdSe/CdTe quantum dots has drastically different characteristics as in CdSe and CdSe/CdS quantum dots. The band alignment, strain effect, and quantum confinement are all important to determine the electronic structures of these systems.