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atomic force microscopy; nanostructure; molecular beam epitaxy; semiconducting III-V materials
Abstract:
We demonstrate vertical alignment of laterally ordered self-
assembled quantum dot (QD) arrays stacked on artificially pre-
patterned substrates with two-dimensional hole arrays. The
initial InGaAs layer is directly grown on the periodically
modulated surface in order to exactly control nucleation sites
of QDs to be stacked. After growing three InGaAs dot layers
with GaAs spacers as a buffer, laterally ordered InAs dots are
grown as an optically active layer. The cross-sectional images
of transmission electron microscopy reveal vertical alignment
of the stacked QDs. Photoluminescence signal at room
temperature is detected from the three-dimensional QD
superlattice. (C) 2002 Elsevier Science B.V. All rights
reserved.
