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Tunable Electronic and Topological Properties of Germanene by Functional Group Modification

Electronic and topological properties of two-dimensional germanene modified by functional group X (X = H, F, OH, CH(3)) at full coverage are studied with first-principles calculation. Without considering the effect of spin-orbit coupling (SOC), all functionalized configurations become semiconductors...

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Autores principales: Ren, Ceng-Ceng, Zhang, Shu-Feng, Ji, Wei-Xiao, Zhang, Chang-Wen, Li, Ping, Wang, Pei-Ji
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5869636/
https://www.ncbi.nlm.nih.gov/pubmed/29509699
http://dx.doi.org/10.3390/nano8030145
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author Ren, Ceng-Ceng
Zhang, Shu-Feng
Ji, Wei-Xiao
Zhang, Chang-Wen
Li, Ping
Wang, Pei-Ji
author_facet Ren, Ceng-Ceng
Zhang, Shu-Feng
Ji, Wei-Xiao
Zhang, Chang-Wen
Li, Ping
Wang, Pei-Ji
author_sort Ren, Ceng-Ceng
collection PubMed
description Electronic and topological properties of two-dimensional germanene modified by functional group X (X = H, F, OH, CH(3)) at full coverage are studied with first-principles calculation. Without considering the effect of spin-orbit coupling (SOC), all functionalized configurations become semiconductors, removing the Dirac cone at K point in pristine germanene. We also find that their band gaps can be especially well tuned by an external strain. When the SOC is switched on, GeX (X = H, CH(3)) is a normal insulator and strain leads to a phase transition to a topological insulator (TI) phase. However, GeX (X = F, OH) becomes a TI with a large gap of 0.19 eV for X = F and 0.24 eV for X = OH, even without external strains. More interestingly, when all these functionalized monolayers form a bilayer structure, semiconductor-metal states are observed. All these results suggest a possible route of modulating the electronic properties of germanene and promote applications in nanoelectronics.
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spelling pubmed-58696362018-03-28 Tunable Electronic and Topological Properties of Germanene by Functional Group Modification Ren, Ceng-Ceng Zhang, Shu-Feng Ji, Wei-Xiao Zhang, Chang-Wen Li, Ping Wang, Pei-Ji Nanomaterials (Basel) Article Electronic and topological properties of two-dimensional germanene modified by functional group X (X = H, F, OH, CH(3)) at full coverage are studied with first-principles calculation. Without considering the effect of spin-orbit coupling (SOC), all functionalized configurations become semiconductors, removing the Dirac cone at K point in pristine germanene. We also find that their band gaps can be especially well tuned by an external strain. When the SOC is switched on, GeX (X = H, CH(3)) is a normal insulator and strain leads to a phase transition to a topological insulator (TI) phase. However, GeX (X = F, OH) becomes a TI with a large gap of 0.19 eV for X = F and 0.24 eV for X = OH, even without external strains. More interestingly, when all these functionalized monolayers form a bilayer structure, semiconductor-metal states are observed. All these results suggest a possible route of modulating the electronic properties of germanene and promote applications in nanoelectronics. MDPI 2018-03-06 /pmc/articles/PMC5869636/ /pubmed/29509699 http://dx.doi.org/10.3390/nano8030145 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Ren, Ceng-Ceng
Zhang, Shu-Feng
Ji, Wei-Xiao
Zhang, Chang-Wen
Li, Ping
Wang, Pei-Ji
Tunable Electronic and Topological Properties of Germanene by Functional Group Modification
title Tunable Electronic and Topological Properties of Germanene by Functional Group Modification
title_full Tunable Electronic and Topological Properties of Germanene by Functional Group Modification
title_fullStr Tunable Electronic and Topological Properties of Germanene by Functional Group Modification
title_full_unstemmed Tunable Electronic and Topological Properties of Germanene by Functional Group Modification
title_short Tunable Electronic and Topological Properties of Germanene by Functional Group Modification
title_sort tunable electronic and topological properties of germanene by functional group modification
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5869636/
https://www.ncbi.nlm.nih.gov/pubmed/29509699
http://dx.doi.org/10.3390/nano8030145
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