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arXiv · 1604.02985

Indium segregation during III-V quantum wire and quantum dot formation on patterned substrates

Stefano T. Moroni·Valeria Dimastrodonato·Tung-Hsun Chung·Gediminas Juska·Agnieszka Gocalinska·Dimitri D. Vvedensky·Emanuele Pelucchi
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Abstract

We report a model for metalorganic vapor-phase epitaxy on non-planar substrates, specifically V-grooves and pyramidal recesses, which we apply to the growth of InGaAs nanostructures. This model, based on a set of coupled reaction-diffusion equations, one for each facet in the system, accounts for the facet-dependence of all kinetic processes (e.g., precursor decomposition, adatom diffusion, and adatom lifetimes) and has been previously applied to account for the temperature, concentration, and temporal-dependence of AlGaAs nanostructures on GaAs (111)B surfaces with V-grooves and pyramidal recesses. In the present study, the growth of In$_{0.12}$Ga$_{0.88}$As quantum wires at the bottom of V-grooves is used to determine a set of optimized kinetic parameters. Based on these parameters, we have modeled the growth of In$_{0.25}$Ga$_{0.75}$As nanostructures formed in pyramidal site-controlled quantum-dot systems, successfully producing a qualitative explanation for the temperature-dependence of their optical properties, which have been reported in previous studies. Finally, we present scanning electron and cross-sectional atomic force microscopy images which show previously unreported facetting at the bottom of the pyramidal recesses that allow quantum dot formation.

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Stefano T. Moroni, Valeria Dimastrodonato, Tung-Hsun Chung, Gediminas Juska, Agnieszka Gocalinska, Dimitri D. Vvedensky, Emanuele Pelucchi. 2016-04-11. Indium segregation during III-V quantum wire and quantum dot formation on patterned substrates. https://doi.org/10.1063/1.4919362

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