Self-formation of hexagonal nanotemplates for growth of pyramidal quantum dots by metalorganic vapor phase epitaxy on patterned substrates

• Published in: Nano research 2016-11, Vol.9 (11), p.3279-3290
• Main Authors: Surrente, Alessandro, Carron, Romain, Gallo, Pascal, Rudra, Alok, Dwir, Benjamin, Kapon, Eli
• Format: Article
• Language: English
• Subjects: Adatoms; Atomic force microscopy; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Chemistry and Materials Science; Computer simulation; Condensed Matter Physics; Curvature; Elevation; Epitaxial growth; Epitaxial layers; Epitaxy; Fluxes; Formations; Gallium arsenide; Growth conditions; Materials Science; Metalorganic chemical vapor deposition; Nanostructure; Nanotechnology; Photons; Pyramids; Quantum dots; Quantum theory; Research Article; Substrates; Symmetry; Thin films; Vapors; 六边形; 图形衬底; 外延法; 有机金属; 模板; 气相外延; 自形成; 量子点
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-016-1206-7

We demonstrate the self-formation of hexagonal nanotemplates on GaAs （111）B substrates patterned with arrays of inverted tetrahedral pyramids during metal-organic vapor phase epitaxy and its role in producing high-symmetry, site-controlled quantum dots （QDs）. By combining atomic force microscopy measurements on progressively thicker GaAs epitaxial layers with kinetic Monte Carlo growth simulations, we demonstrate self-maintained symmetry elevation of the QD formation sites from three-fold to six-fold symmetry. This symmetry elevation stems from adatom fluxes directed towards the high-curvature sites of the template, resulting in the formation of a fully three-dimensional hexagonal template after the deposition of relatively thin GaAs layers. We identified the growth conditions for consistently achieving a hexagonal pyramid bottom, which are useful for producing high-symmetry QDs for efficient generation of entangled photons.