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arXiv · 1311.1448

Ge Quantum Dots Encapsulated by AlAs Grown by Molecular Beam Epitaxy on GaAs Without Extended Defects

Meng Qi·Chad A. Stephenson·Vladimir Protasenko·William A. O'Brien·Alexander Mintairov·Huili Grace Xing·Mark A. Wistey
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Abstract

We demonstrate nearly-spherical, strain-free, self-assembled Ge quantum dots (QDs) fully encapsulated by AlAs, grown on (100) GaAs by molecular beam epitaxy (MBE). The QDs were formed without a wetting layer using a high temperature, in-situ anneal. Subsequent AlAs overgrowth was free from threading dislocations and anti-phase domains. The straddling band alignment for Ge in AlAs promises strong and tunable confinement for both electrons and holes. The reflection high-energy electron diffraction (RHEED) pattern changed from 2x3 to 2x5 with anneal, which can be explained by surface reconstructions based on the electron-counting model.

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Meng Qi, Chad A. Stephenson, Vladimir Protasenko, William A. O'Brien, Alexander Mintairov, Huili Grace Xing, Mark A. Wistey. 2013-11-06. Ge Quantum Dots Encapsulated by AlAs Grown by Molecular Beam Epitaxy on GaAs Without Extended Defects. https://doi.org/10.1063/1.4866278

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