Γ-X Intervalley Electron Transfer Rates in Type-II AlxGa1−xAs/AlAs Superlattices
Reduction of the GaAs well width in (GaAs) m /(AlAs) n (m,n = number of monolayers) superlattices (SL) permits tuning of the lowest Γ-conduction band state in the GaAs above the X-minimum in the AlAs layers for m ≤ 12. In such a staggered type-II SL the highest valence band state is contained in the GaAs layers and the lowest conduction band state in the AlAs slabs. After photoexcitation of hot electrons and holes in the confined Γ conduction- and valence band states of the GaAs, the holes stay in the GaAs during relaxation and the electrons scatter to the energetically lower X-related states of the AlAs.
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