2004/05/02 by Seungwon Lee, Olga L. Lazarenkova, Fabiano Oyafuso +2
Engineering · Physics and Astronomy · #Composite material #Condensed matter physics #Electron #Materials science #Nanotechnology #Physics #Quantum and electron transport phenomena #Quantum dot #Semiconductor Quantum Structures and Devices #Semiconductor materials and devices #Wetting #Wetting layer #Wetting transition #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.70.125307
14 pages, 3 figures, and 3 tables
arxiv created 2004/05/02 · openalex publication_date 2004/09/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The effect of wetting layers on the strain and electronic structure of InAs self-assembled quantum dots grown on GaAs is investigated with an atomistic valence-force-field model and an empirical tight-binding model. By comparing a dot with and without a wetting layer, we find that the inclusion of the wetting layer weakens the strain inside the dot by only 1% relative change, while it reduces the energy gap between a confined electron and hole level by as much as 10%. The small change in the strain distribution indicates that strain relaxes only little through the thin wetting layer. The large reduction of the energy gap is attributed to the increase of the confining-potential width rather than the change of the potential height. First-order perturbation calculations or, alternatively, the addition of an InAs disk below the quantum dot confirm this conclusion. The effect of the wetting layer on the wave function is qualitatively different for the weakly confined electron state and the strongly confined hole state. The electron wave function shifts from the buffer to the wetting layer, while the hole shifts from the dot to the wetting layer.