Unusual role of the substrate in droplet‐induced GaAs/AlGaAs quantum‐dot pairs |
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| Authors: | Zh M Wang Yu I Mazur K A Sablon T D Mishima M B Johnson G J Salamo |
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| Institution: | 1. Institute of Nanoscale Science and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA;2. Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA |
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| Abstract: | The structural complexity of GaAs quantum‐dot pairs has been revealed by cross‐sectional transmission electron microscopy. As a result of high‐temperature droplet epitaxy, the AlGaAs substrate beneath the quantum‐dot pairs is no longer immobile and its reconstruction is observed to define the crystallization of gallium droplets under an arsenic flux. The GaAs quantum‐dot pairs are immersed into the substrate and further confined by the re‐distributed AlGaAs materials above the substrate plane. There are two underlying mechanisms responsible for the final nanostructure configuration, melt‐back etching by the gallium droplets and preferential crystallization of gallium around reconstructed sidewalls. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
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| Keywords: | 68 37 Lp 68 37 Ps 68 55 Ag 68 65 Hk 81 15 Hi 81 16 Dn |
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