InAs/GaAs(001) quantum dots close to thermodynamic equilibrium

Costantini, G.; Manzano, C.; Songmuang, R.; Schmidt, O. G.; Kern, K.
May 2003
Applied Physics Letters;5/12/2003, Vol. 82 Issue 19, p3194
Academic Journal
InAs/GaAs(001) quantum dots are grown at high temperature and extremely low flux and analyzed by in situ scanning tunneling microscopy. A bimodal distribution of dots is observed, composed of "small" and "large" islands. While the former show a broad distribution of sizes and shapes, the latter appear to be highly uniform and have a truncated pyramid shape with irregular octagonal base. (110) and (111) facets are identified and atomically resolved showing (1 × 1) and (2 × 2) surface reconstructions, respectively. The shape of the large quantum dots is in excellent agreement with recent theoretical predictions, proving that the chosen deposition conditions are close to thermodynamic equilibrium.


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