Anisotropic Confinement, Electronic Coupling and Strain Induced Effects Detected by Valence-Band Anisotropy in Self-Assembled Quantum Dots

• Main Authors: Marega E, Liang BL, Mazur Yu, Salamo GJ, Malachias A, Trallero-Giner C, Villegas-Lelovsky L, Teodoro MD, Lopez-Richard V, Calseverino C, Marques GE
• Format: Article
• Language: English
• Published: SpringerOpen 2011-01-01
• Series: Nanoscale Research Letters
• Subjects: Molecular beam epitaxy; Self-assembled quantum dots; Inter-dot coupling; Anisotropic effects; Linear polarized photoluminescence emission; Grazing-incidence X-ray diffraction synchrotron; Optoelectronic
• Online Access: http://www.nanoscalereslett.com/content/6/1/56
• ISSN: 1931-7573; 1556-276X

<p>Abstract</p> <p>A method to determine the effects of the geometry and lateral ordering on the electronic properties of an array of one-dimensional self-assembled quantum dots is discussed. A model that takes into account the valence-band anisotropic effective masses and strain effects must be used to describe the behavior of the photoluminescence emission, proposed as a clean tool for the characterization of dot anisotropy and/or inter-dot coupling. Under special growth conditions, such as substrate temperature and Arsenic background, 1D chains of In_0.4Ga_0.6 As quantum dots were grown by molecular beam epitaxy. Grazing-incidence X-ray diffraction measurements directly evidence the strong strain anisotropy due to the formation of quantum dot chains, probed by polarization-resolved low-temperature photoluminescence. The results are in fair good agreement with the proposed model.</p>