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

doi:10.1063/1.4866278

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

Materials Science 2014-03-05 v1

Authors: 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.

Keywords

Ge quantum dots AlAs encapsulation molecular beam epitaxy GaAs substrate self-assembled strain-free band alignment surface reconstruction

Cite

@article{arxiv.1311.1448,
  title  = {Ge Quantum Dots Encapsulated by AlAs Grown by Molecular Beam Epitaxy on GaAs Without Extended Defects},
  author = {Meng Qi and Chad A. Stephenson and Vladimir Protasenko and William A. O'Brien and Alexander Mintairov and Huili Grace Xing and Mark A. Wistey},
  journal= {arXiv preprint arXiv:1311.1448},
  year   = {2014}
}

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14 pages, 5 figures, submitted to Applied Physics Letters

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

Abstract

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