Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations
Using first-principles calculations, we investigate the geometric structures and electronic properties of porous silicene and germanene nanosheets, which are the Si and Ge analogues of α−graphyne (referred to as silicyne and germanyne). It is found that the elemental silicyne and germanyne sheets ar...
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| Format: | Online |
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Springer US
2015
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4312312/ |
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pubmed-43123122015-04-07 Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations Ding, Yi Wang, Yanli Nano Express Using first-principles calculations, we investigate the geometric structures and electronic properties of porous silicene and germanene nanosheets, which are the Si and Ge analogues of α−graphyne (referred to as silicyne and germanyne). It is found that the elemental silicyne and germanyne sheets are energetically unfavourable. However, after the C-substitution, the hybrid graphyne-like sheets (c-silicyne/c-germanyne) possess robust energetic and dynamical stabilities. Different from silicene and germanene, c-silicyne is a flat sheet, and c-germanyne is buckled with a distinct half-hilled conformation. Such asymmetric buckling structure causes the semiconducting behaviour into c-germanyne. While in c-silicyne, the semimetallic Dirac-like property is kept at the nonmagnetic state, but a spontaneous antiferromagnetism produces the massive Dirac fermions and opens a sizeable gap between Dirac cones. A tensile strain can further enhance the antiferromagnetism, which also linearly modulates the gap value without altering the direct-bandgap feature. Through strain engineering, c-silicyne can form a type-II band alignment with the MoS 2 sheet. The combined c-silicyne/MoS 2 nanostructure has a high power conversion efficiency beyond 20% for photovoltaic solar cells, enabling a fascinating utilization in the fields of solar energy and nano-devices. Springer US 2015-01-27 /pmc/articles/PMC4312312/ /pubmed/25852311 http://dx.doi.org/10.1186/s11671-014-0704-3 Text en © Ding and Wang; licensee Springer. 2015 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Ding, Yi Wang, Yanli |
| spellingShingle |
Ding, Yi Wang, Yanli Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| author_facet |
Ding, Yi Wang, Yanli |
| author_sort |
Ding, Yi |
| title |
Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| title_short |
Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| title_full |
Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| title_fullStr |
Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| title_full_unstemmed |
Unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| title_sort |
unusual structural and electronic properties of porous silicene and germanene: insights from first-principles calculations |
| description |
Using first-principles calculations, we investigate the geometric structures and electronic properties of porous silicene and germanene nanosheets, which are the Si and Ge analogues of α−graphyne (referred to as silicyne and germanyne). It is found that the elemental silicyne and germanyne sheets are energetically unfavourable. However, after the C-substitution, the hybrid graphyne-like sheets (c-silicyne/c-germanyne) possess robust energetic and dynamical stabilities. Different from silicene and germanene, c-silicyne is a flat sheet, and c-germanyne is buckled with a distinct half-hilled conformation. Such asymmetric buckling structure causes the semiconducting behaviour into c-germanyne. While in c-silicyne, the semimetallic Dirac-like property is kept at the nonmagnetic state, but a spontaneous antiferromagnetism produces the massive Dirac fermions and opens a sizeable gap between Dirac cones. A tensile strain can further enhance the antiferromagnetism, which also linearly modulates the gap value without altering the direct-bandgap feature. Through strain engineering, c-silicyne can form a type-II band alignment with the MoS 2 sheet. The combined c-silicyne/MoS 2 nanostructure has a high power conversion efficiency beyond 20% for photovoltaic solar cells, enabling a fascinating utilization in the fields of solar energy and nano-devices. |
| publisher |
Springer US |
| publishDate |
2015 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4312312/ |
| _version_ |
1613182678326050816 |