Photoluminescence of compact GeSi quantum dot groups with increased probability of finding an electron in Ge.

Autor: Zinovieva AF; Rzhanov Institute of Semiconductor Physics, SB RAS, 630090, Novosibirsk, Russia.; Novosibirsk State University, 630090, Novosibirsk, Russia., Zinovyev VA; Rzhanov Institute of Semiconductor Physics, SB RAS, 630090, Novosibirsk, Russia. zinoviev@isp.nsc.ru., Nenashev AV; Rzhanov Institute of Semiconductor Physics, SB RAS, 630090, Novosibirsk, Russia.; Novosibirsk State University, 630090, Novosibirsk, Russia., Teys SA; Rzhanov Institute of Semiconductor Physics, SB RAS, 630090, Novosibirsk, Russia., Dvurechenskii AV; Rzhanov Institute of Semiconductor Physics, SB RAS, 630090, Novosibirsk, Russia.; Novosibirsk State University, 630090, Novosibirsk, Russia., Borodavchenko OM; Scientific-Practical Material Research Centre of the National Academy of Science of Belarus, P. Brovki, 220072, Minsk, Belarus., Zhivulko VD; Scientific-Practical Material Research Centre of the National Academy of Science of Belarus, P. Brovki, 220072, Minsk, Belarus., Mudryi AV; Scientific-Practical Material Research Centre of the National Academy of Science of Belarus, P. Brovki, 220072, Minsk, Belarus.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2020 Jun 09; Vol. 10 (1), pp. 9308. Date of Electronic Publication: 2020 Jun 09.
DOI: 10.1038/s41598-020-64098-x
Abstrakt: The photoluminescence (PL) of the combined Ge/Si structures representing a combination of large (200-250 nm) GeSi disk-like quantum dots (nanodisks) and four-layered stacks of compact groups of smaller (30 nm) quantum dots grown in the strain field of nanodisks was studied. The multiple increase in the PL intensity was achieved by the variation of parameters of vertically aligned quantum dot groups. The experimental results were analyzed on the basis of calculations of energy spectra, electron and hole wave functions. It was found that the quantum dot arrangement in compact groups provides the effective electron localization in Δ x,y -valleys with an almost equal probability of finding an electron in the Si spacer and Ge barrier. As a result, the main channels of radiative recombination in the structures under study correspond to spatially direct optical transitions.
Databáze: MEDLINE
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