Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi
One-monolayer (ML) (thin) and 5-ML (thick) Si films were grown on the α-phase Si(111)√3 × √3R30°-Bi at a low substrate temperature of 200 °C. Si films have been studied in situ by reflection electron energy loss spectroscopy (REELS) and Auger electron spectroscopy, as a function of the electron beam...
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MDPI AG
2022-02-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/5/1730 |
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| author | David Garagnani Paola De Padova Carlo Ottaviani Claudio Quaresima Amanda Generosi Barbara Paci Bruno Olivieri Mieczysław Jałochowski Mariusz Krawiec |
| author_facet | David Garagnani Paola De Padova Carlo Ottaviani Claudio Quaresima Amanda Generosi Barbara Paci Bruno Olivieri Mieczysław Jałochowski Mariusz Krawiec |
| author_sort | David Garagnani |
| collection | DOAJ |
| description | One-monolayer (ML) (thin) and 5-ML (thick) Si films were grown on the α-phase Si(111)√3 × √3R30°-Bi at a low substrate temperature of 200 °C. Si films have been studied in situ by reflection electron energy loss spectroscopy (REELS) and Auger electron spectroscopy, as a function of the electron beam incidence angle α and low-energy electron diffraction (LEED), as well as ex situ by grazing incidence X-ray diffraction (GIXRD). Scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS) were also reported. The REELS spectra, taken at the Si K absorption edge (~1.840 KeV), reveal the presence of two distinct loss structures attributed to transitions 1<i>s</i>→π* and 1<i>s</i>→σ* according to their intensity dependence on α, attesting to the <i>sp</i><sup>2</sup>-like hybridization of the silicon valence orbitals in both thin and thick Si films. The synthesis of a silicon allotrope on the α-phase of Si(111)√3 × √3R30°-Bi substrate was demonstrated by LEED patterns and GIXRD that discloses the presence of a Si stack of 3.099 (3) Å and a √3 × √3 unit cell of 6.474 Å, typically seen for multilayer silicene. STM and STS measurements corroborated the findings. These measurements provided a platform for the new √3 × √3R30° Si allotrope on a Si(111)√3 × √3 R30°-Bi template, paving the way for realizing topological insulator heterostructures from different two-dimensional materials, Bi and Si. |
| first_indexed | 2024-03-09T20:33:35Z |
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| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T20:33:35Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-f65471b3cdf2437c85afa56909562dc12023-11-23T23:18:00ZengMDPI AGMaterials1996-19442022-02-01155173010.3390/ma15051730Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-BiDavid Garagnani0Paola De Padova1Carlo Ottaviani2Claudio Quaresima3Amanda Generosi4Barbara Paci5Bruno Olivieri6Mieczysław Jałochowski7Mariusz Krawiec8Consiglio Nazionale delle Ricerche—ISM, Via Fosso del Cavaliere 100, 00133 Roma, ItalyConsiglio Nazionale delle Ricerche—ISM, Via Fosso del Cavaliere 100, 00133 Roma, ItalyConsiglio Nazionale delle Ricerche—ISM, Via Fosso del Cavaliere 100, 00133 Roma, ItalyConsiglio Nazionale delle Ricerche—ISM, Via Fosso del Cavaliere 100, 00133 Roma, ItalyConsiglio Nazionale delle Ricerche—ISM, Via Fosso del Cavaliere 100, 00133 Roma, ItalyConsiglio Nazionale delle Ricerche—ISM, Via Fosso del Cavaliere 100, 00133 Roma, ItalyConsiglio Nazionale delle Ricerche—ISAC, Via Fosso del Cavaliere 100, 00133 Roma, ItalyInstitute of Physics, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 1, 20-031 Lublin, PolandInstitute of Physics, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 1, 20-031 Lublin, PolandOne-monolayer (ML) (thin) and 5-ML (thick) Si films were grown on the α-phase Si(111)√3 × √3R30°-Bi at a low substrate temperature of 200 °C. Si films have been studied in situ by reflection electron energy loss spectroscopy (REELS) and Auger electron spectroscopy, as a function of the electron beam incidence angle α and low-energy electron diffraction (LEED), as well as ex situ by grazing incidence X-ray diffraction (GIXRD). Scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS) were also reported. The REELS spectra, taken at the Si K absorption edge (~1.840 KeV), reveal the presence of two distinct loss structures attributed to transitions 1<i>s</i>→π* and 1<i>s</i>→σ* according to their intensity dependence on α, attesting to the <i>sp</i><sup>2</sup>-like hybridization of the silicon valence orbitals in both thin and thick Si films. The synthesis of a silicon allotrope on the α-phase of Si(111)√3 × √3R30°-Bi substrate was demonstrated by LEED patterns and GIXRD that discloses the presence of a Si stack of 3.099 (3) Å and a √3 × √3 unit cell of 6.474 Å, typically seen for multilayer silicene. STM and STS measurements corroborated the findings. These measurements provided a platform for the new √3 × √3R30° Si allotrope on a Si(111)√3 × √3 R30°-Bi template, paving the way for realizing topological insulator heterostructures from different two-dimensional materials, Bi and Si.https://www.mdpi.com/1996-1944/15/5/1730silicene-likeα-phase Si(111)√3 × √3R30°-BiSi K-edge<i>sp</i><sup>2</sup>-like hybridizationreflection electron energy loss spectroscopyAuger spectroscopy |
| spellingShingle | David Garagnani Paola De Padova Carlo Ottaviani Claudio Quaresima Amanda Generosi Barbara Paci Bruno Olivieri Mieczysław Jałochowski Mariusz Krawiec Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi Materials silicene-like α-phase Si(111)√3 × √3R30°-Bi Si K-edge <i>sp</i><sup>2</sup>-like hybridization reflection electron energy loss spectroscopy Auger spectroscopy |
| title | Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi |
| title_full | Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi |
| title_fullStr | Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi |
| title_full_unstemmed | Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi |
| title_short | Evidence of <i>sp</i><sup>2</sup>-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi |
| title_sort | evidence of i sp i sup 2 sup like hybridization of silicon valence orbitals in thin and thick si grown on α phase si 111 √3 √3r30° bi |
| topic | silicene-like α-phase Si(111)√3 × √3R30°-Bi Si K-edge <i>sp</i><sup>2</sup>-like hybridization reflection electron energy loss spectroscopy Auger spectroscopy |
| url | https://www.mdpi.com/1996-1944/15/5/1730 |
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