Structural Properties and Energy Spectrum of Novel GaSb/AlP Self-Assembled Quantum Dots

Demid S Abramkin; Mikhail O Petrushkov; Dmitrii B Bogomolov; Eugeny A Emelyanov; Mikhail Yu Yesin; Andrey V Vasev; Alexey A Bloshkin; Eugeny S Koptev; Mikhail A Putyato; Victor V Atuchin; Valery V Preobrazhenskii

doi:10.3390/nano13050910

Structural Properties and Energy Spectrum of Novel GaSb/AlP Self-Assembled Quantum Dots

Nanomaterials (Basel). 2023 Feb 28;13(5):910. doi: 10.3390/nano13050910.

Authors

Affiliations

¹ Laboratory of Molecular-Beam Epitaxy of A3B5 Compounds, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
² Department of Physics, Novosibirsk State University, Novosibirsk 630090, Russia.
³ Laboratory of Physical Bases of Semiconductor Heterostructures Epitaxy, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
⁴ Laboratory of Molecular-Beam Epitaxy of Elementary Semiconductors and A3B5 Compounds, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
⁵ Laboratory of Nonequilibrium Semiconductor Systems, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
⁶ Department of Automation and Computer Engineering, Novosibirsk State Technical University, Novosibirsk 630073, Russia.
⁷ Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
⁸ Research and Development Department, Kemerovo State University, Kemerovo 650000, Russia.
⁹ R&D Center "Advanced Electronic Technologies", Tomsk State University, Tomsk 634034, Russia.
¹⁰ Department of Industrial Machinery Design, Novosibirsk State Technical University, Novosibirsk 630073, Russia.

Abstract

In this work, the formation, structural properties, and energy spectrum of novel self-assembled GaSb/AlP quantum dots (SAQDs) were studied by experimental methods. The growth conditions for the SAQDs' formation by molecular beam epitaxy on both matched GaP and artificial GaP/Si substrates were determined. An almost complete plastic relaxation of the elastic strain in SAQDs was reached. The strain relaxation in the SAQDs on the GaP/Si substrates does not lead to a reduction in the SAQDs luminescence efficiency, while the introduction of dislocations into SAQDs on the GaP substrates induced a strong quenching of SAQDs luminescence. Probably, this difference is caused by the introduction of Lomer 90°-dislocations without uncompensated atomic bonds in GaP/Si-based SAQDs, while threading 60°-dislocations are introduced into GaP-based SAQDs. It was shown that GaP/Si-based SAQDs have an energy spectrum of type II with an indirect bandgap and the ground electronic state belonging to the X-valley of the AlP conduction band. The hole localization energy in these SAQDs was estimated equal to 1.65-1.70 eV. This fact allows us to predict the charge storage time in the SAQDs to be as long as >>10 years, and it makes GaSb/AlP SAQDs promising objects for creating universal memory cells.

Keywords: GaSb/AlP; QD-Flash; energy spectrum; molecular beam epitaxy; quantum dots; structural properties.

Abstract

Grants and funding