| Alternative title | Optical emission from germanium nanocrystals |
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| Download | - View final version: Editors' choice—optical emission from germanium nanocrystals (PDF, 1.2 MiB)
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| DOI | Resolve DOI: https://doi.org/10.1149/2.0041812jss |
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| Author | Search for: Rowell, N. L.1ORCID identifier: https://orcid.org/0000-0001-7616-9396; Search for: Lockwood, D. J.1ORCID identifier: https://orcid.org/0000-0002-3001-2630; Search for: Houghton, D. C.2; Search for: Noël, J.-P.2; Search for: Baribeau, J.-M.2 |
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| Affiliation | - National Research Council Canada. Metrology Research Centre
- National Research Council Canada
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| Format | Text, Article |
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| Abstract | We analyze the intense photoluminescence (PL) observed at energies from 600 to 1100 meV for a large number of Si₁₋ₓGeₓ epitaxial layers grown by molecular beam epitaxy. In the present work we show that this previously unexplained broad PL peak can be assigned to Ge nanocrystals (NCs) self-assembled within the SiGe layers. These NCs are assumed to be lattice matched to the SiGe in the vertical, growth direction. A consequence of this assignment is that as the Ge-fraction in the SiGe layer increases the vertical strain in the NCs changes from compressive to tensile at x ~ 0.36, lowering the NC bandgap (BG) below that of bulk Ge. We examine the PL results for more than 60 samples exhibiting this broad PL peak by examining how it follows the strained Ge BG for x from 0.05 to 0.53. The PL is resolvable as two narrower peaks separated by the momentum conserving phonon energy for Ge. Strain and confinement shifted NC bound exciton energies calculated numerically agree well with the measured ones. When Raman scattering results were examined for some of the same samples, the phonon mode frequencies obtained provided valuable corroborative evidence for the presence of the Ge NCs. |
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| Publication date | 2018-11-29 |
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| Publisher | Electrochemical Society
IOP |
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| Licence | |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 0ef78934-9319-4bd4-a136-85f0bebdea9f |
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| Record created | 2020-06-16 |
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| Record modified | 2021-08-30 |
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