Self-organized formation of shell-like InAs/GaAs quantum dot ensembles |
| |
Authors: | UW Pohl K Pötschke VA Shchukin DE Jesson |
| |
Institution: | a Technische Universität Berlin, Institut für Festkörperphysik PN5-2, Hardenbergstr. 36, 10623 Berlin, Germany b Abraham Ioffe Physical Technical Institute, St. Petersburg 194021, Russia c School of Physics, Monash University, Victoria 3800, Australia |
| |
Abstract: | Formation of a multimodal quantum dot (QD) ensemble by strained layer epitaxy of InAs on GaAs near the critical value for the onset of the 2D-3D transition is studied. Reflection anisotropy spectroscopy is employed to confirm that a smooth surface is maintained during strained layer growth prior to QD formation. Instantaneous capping after deposition leads to InAs quantum wells with some thickness flucuations. Multimodal QD InAs ensembles form after an at least short growth interruption prior to cap layer deposition. The QDs consist of pure InAs with heights varying in steps of complete InAs monolayers. Related exciton energies indicate a simultaneous increase of both height and lateral extension, i.e. a shell-like increase of sizes. The formation of the multimodal QD ensemble is described by a kinetic approach. A growth scenario is presented where QDs having initially shorter base length stop vertical growth at a smaller height, accounting for the experimentally observed shell-like sub-ensemble structure. |
| |
Keywords: | 81 07 Ta 81 16 Dn 81 05 Ea 81 15 Gh 78 66 Fd |
本文献已被 ScienceDirect 等数据库收录! |
|