Fabrication and characterization of Si 1- x Ge x nanocrystals in as-grown and annealed structures: a comparative study.

Autor: Sultan MT; Reykjavik University, School of Science and Engineering, IS-101 Reykjavik, Iceland., Maraloiu AV; National Institute of Materials Physics, 077125 Magurele, Romania., Stavarache I; National Institute of Materials Physics, 077125 Magurele, Romania., Gudmundsson JT; Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland.; Department of Space and Plasma Physics, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden., Manolescu A; Reykjavik University, School of Science and Engineering, IS-101 Reykjavik, Iceland., Teodorescu VS; National Institute of Materials Physics, 077125 Magurele, Romania.; Academy of Romanian Scientists, 050094 Bucharest, Romania., Ciurea ML; National Institute of Materials Physics, 077125 Magurele, Romania.; Academy of Romanian Scientists, 050094 Bucharest, Romania., Svavarsson HG; Reykjavik University, School of Science and Engineering, IS-101 Reykjavik, Iceland.
Jazyk: angličtina
Zdroj: Beilstein journal of nanotechnology [Beilstein J Nanotechnol] 2019 Sep 17; Vol. 10, pp. 1873-1882. Date of Electronic Publication: 2019 Sep 17 (Print Publication: 2019).
DOI: 10.3762/bjnano.10.182
Abstrakt: Multilayer structures comprising of SiO 2 /SiGe/SiO 2 and containing SiGe nanoparticles were obtained by depositing SiO 2 layers using reactive direct current magnetron sputtering (dcMS), whereas, Si and Ge were co-sputtered using dcMS and high-power impulse magnetron sputtering (HiPIMS). The as-grown structures subsequently underwent rapid thermal annealing (550-900 °C for 1 min) in N 2 ambient atmosphere. The structures were investigated using X-ray diffraction, high-resolution transmission electron microscopy together with spectral photocurrent measurements, to explore structural changes and corresponding properties. It is observed that the employment of HiPIMS facilitates the formation of SiGe nanoparticles (2.1 ± 0.8 nm) in the as-grown structure, and that presence of such nanoparticles acts as a seed for heterogeneous nucleation, which upon annealing results in the periodically arranged columnar self-assembly of SiGe core-shell nanocrystals. An increase in photocurrent intensity by more than an order of magnitude was achieved by annealing. Furthermore, a detailed discussion is provided on strain development within the structures, the consequential interface characteristics and its effect on the photocurrent spectra.
(Copyright © 2019, Sultan et al.; licensee Beilstein-Institut.)
Databáze: MEDLINE
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