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Youzi M, Kianezhad M, Vaezi M, Nejat Pishkenari H. Motion of nanovehicles on pristine and vacancy-defected silicene: implications for controlled surface motion. Phys Chem Chem Phys 2023; 25:28895-28910. [PMID: 37855185 DOI: 10.1039/d3cp02835f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Understanding the motion of surface-rolling nanomachines has attracted lots of attention in recent studies, due to their ability in carrying molecular payloads and nanomaterials on the surface. Controlling the surface motion of these nanovehicles is beneficial in the fabrication of nano-transportation systems. In the present study, molecular dynamics (MD) simulations alongside the potential energy analysis have been utilized to investigate the motion of C60 and C60-based nanovehicles on the silicene monolayer. Nano-machine simulations are performed using molecular mechanic forcefield. Compared with graphene and hexagonal boron-nitride, the molecules experience a higher energy barrier on the silicene, which leads to a lower diffusion coefficient and higher activation energy of C60 and nanomachines. Overcoming the maximum energy barrier against sliding motion is more probable at higher temperatures where the nanomachines receive higher thermal energy. After evaluating the motion of molecules around local vacancies, we introduce a nanoroad structure that can restrict surface motion. The motion of C60 and nanovehicles over the surface is limited to the width of nanorods up to a certain temperature. To increase the controllability of the motion, a thermal gradient has been applied to the surface and the molecules move toward the lower temperature regions, where they find lower energy levels. Comparing the results of this study with other investigations regarding the surface motion of molecules on boron-nitride and graphene surfaces brings forth the idea of controlling the motion by silicene-based hybrid substrates, which can be further investigated.
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Affiliation(s)
- Mehrdad Youzi
- Department of Civil and Environmental Engineering, University of California Irvine, Irvine, USA
| | - Mohammad Kianezhad
- Department of Structural Engineering, University of California-San Diego, La Jolla, CA, 92093-0085, USA
| | - Mehran Vaezi
- Institute for Nanoscience and Nanotechnology (INST), Sharif University of Technology, Tehran, Iran
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2
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Huy HA, Ho QD, Tuan TQ, Le OK, Le Hoai Phuong N. Dumbbell configuration of silicon adatom defects on silicene nanoribbons. Sci Rep 2021; 11:14374. [PMID: 34257371 PMCID: PMC8277868 DOI: 10.1038/s41598-021-93465-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/21/2021] [Indexed: 11/09/2022] Open
Abstract
Using density functional theory (DFT), we performed theoretical investigation on structural, energetic, electronic, and magnetic properties of pure armchair silicene nanoribbons with edges terminated with hydrogen atoms (ASiNRs:H), and the absorptions of silicon (Si) atom(s) on the top of ASiNRs:H. The calculated results show that Si atoms prefer to adsorb on the top site of ASiNRs:H and form the single- and/or di-adatom defects depending on the numbers. Si absorption defect(s) change electronic and magnetic properties of ASiNRs:H. Depending on the adsorption site the band gap of ASiNRs:H can be larger or smaller. The largest band gap of 1 Si atom adsorption is 0.64 eV at site 3, the adsorption of 2 Si atoms has the largest band gap of 0.44 eV at site 1-D, while the adsorption at sites5 and 1-E turn into metallic. The formation energies of Si adsorption show that adatom defects in ASiNRs:H are more preferable than pure ASiNRs:H with silicon atom(s). 1 Si adsorption prefers to be added on the top site of a Si atom and form a single-adatom defect, while Si di-adatom defect has lower formation energy than the single-adatom and the most energetically favorable adsorption is at site 1-F. Si adsorption atoms break spin-degeneracy of ASiNRs:H lead to di-adatom defect at site 1-G has the highest spin moment. Our results suggest new ways to engineer the band gap and magnetic properties silicene materials.
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Affiliation(s)
- Huynh Anh Huy
- Department of Physics, School of Education, Can Tho University, Can Tho City, Viet Nam
| | - Quoc Duy Ho
- Faculty of General Sciences, Can Tho University of Technology, Can Tho City, Viet Nam.
| | - Truong Quoc Tuan
- Department of Physics, College of Natural Sciences, Can Tho University, Can Tho City, Viet Nam
| | - Ong Kim Le
- Department of Physics, College of Natural Sciences, Can Tho University, Can Tho City, Viet Nam
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Pham HD, Su WP, Nguyen TDH, Tran NTT, Lin MF. Rich p-type-doping phenomena in boron-substituted silicene systems. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200723. [PMID: 33489254 PMCID: PMC7813228 DOI: 10.1098/rsos.200723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 10/19/2020] [Indexed: 06/12/2023]
Abstract
The essential properties of monolayer silicene greatly enriched by boron substitutions are thoroughly explored through first-principles calculations. Delicate analyses are conducted on the highly non-uniform Moire superlattices, atom-dominated band structures, charge density distributions and atom- and orbital-decomposed van Hove singularities. The hybridized 2p z -3p z and [2s, 2p x , 2p y ]-[3s, 3p x , 3p y ] bondings, with orthogonal relations, are obtained from the developed theoretical framework. The red-shifted Fermi level and the modified Dirac cones/π bands/σ bands are clearly identified under various concentrations and configurations of boron-guest atoms. Our results demonstrate that the charge transfer leads to the non-uniform chemical environment that creates diverse electronic properties.
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Affiliation(s)
- Hai Duong Pham
- Center of General Studies, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
| | - Wu-Pei Su
- Department of Physics, University of Houston, Houston, 77204 TX, USA
| | | | - Ngoc Thanh Thuy Tran
- Hierarchical Green-Energy Materials (Hi-GEM) Research Center, National Cheng Kung University, Tainan 70101, Taiwan
| | - Ming-Fa Lin
- Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan
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Khalkhali M, Rajabpour A, Khoeini F. Thermal transport across grain boundaries in polycrystalline silicene: A multiscale modeling. Sci Rep 2019; 9:5684. [PMID: 30952974 PMCID: PMC6450874 DOI: 10.1038/s41598-019-42187-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/26/2019] [Indexed: 11/17/2022] Open
Abstract
During the fabrication process of large scale silicene, through common chemical vapor deposition (CVD) technique, polycrystalline films are quite likely to be produced, and the existence of Kapitza thermal resistance along grain boundaries could result in substantial changes of their thermal properties. In the present study, the thermal transport along polycrystalline silicene was evaluated by performing a multiscale method. Non-equilibrium molecular dynamics simulations (NEMD) was carried out to assess the interfacial thermal resistance of various constructed grain boundaries in silicene. The effects of tensile strain and the mean temperature on the interfacial thermal resistance were also examined. In the following stage, the effective thermal conductivity of polycrystalline silicene was investigated considering the effects of grain size and tensile strain. Our results indicate that the average values of Kapitza conductance at grain boundaries at room temperature were estimated to be nearly 2.56 × 109 W/m2 K and 2.46 × 109 W/m2 K through utilizing Tersoff and Stillinger-Weber interatomic potentials respectively. Also, in spite of the mean temperature, whose increment does not change Kapitza resistance, the interfacial thermal resistance could be controlled by applying strain. Furthermore, it was found that by tuning the grain size of polycrystalline silicene, its thermal conductivity could be modulated up to one order of magnitude.
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Affiliation(s)
- Maryam Khalkhali
- Department of Physics, University of Zanjan, Zanjan, 45195-313, Iran
| | - Ali Rajabpour
- Mechanical Engineering Department, Imam Khomeini International University, Qazvin, 34148-96818, Iran
| | - Farhad Khoeini
- Department of Physics, University of Zanjan, Zanjan, 45195-313, Iran.
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5
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Galashev AY, Ivanichkina KA. Computer Test of a New Silicene Anode for Lithium‐Ion Batteries. ChemElectroChem 2019. [DOI: 10.1002/celc.201900119] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alexander Y. Galashev
- Institute of High-Temperature ElectrochemistryUral Branch, Russian Academy of Sciences Sofia Kovalevskaya Str. 22 Yekaterinburg 620990 Russia
- Ural Federal University named after the first President of Russia B.N. Yeltsin Mira Str., 19 Yekaterinburg 620002 Russia
| | - Ksenia A. Ivanichkina
- Institute of High-Temperature ElectrochemistryUral Branch, Russian Academy of Sciences Sofia Kovalevskaya Str. 22 Yekaterinburg 620990 Russia
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Krawiec M. Functionalization of group-14 two-dimensional materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:233003. [PMID: 29708504 DOI: 10.1088/1361-648x/aac149] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The great success of graphene has boosted intensive search for other single-layer thick materials, mainly composed of group-14 atoms arranged in a honeycomb lattice. This new class of two-dimensional (2D) crystals, known as 2D-Xenes, has become an emerging field of intensive research due to their remarkable electronic properties and the promise for a future generation of nanoelectronics. In contrast to graphene, Xenes are not completely planar, and feature a low buckled geometry with two sublattices displaced vertically as a result of the interplay between sp2 and sp3 orbital hybridization. In spite of the buckling, the outstanding electronic properties of graphene governed by Dirac physics are preserved in Xenes too. The buckled structure also has several advantages over graphene. Together with the spin-orbit (SO) interaction it may lead to the emergence of various experimentally accessible topological phases, like the quantum spin Hall effect. This in turn would lead to designing and building new electronic and spintronic devices, like topological field effect transistors. In this regard an important issue concerns the electron energy gap, which for Xenes naturally exists owing to the buckling and SO interaction. The electronic properties, including the magnitude of the energy gap, can further be tuned and controlled by external means. Xenes can easily be functionalized by substrate, chemical adsorption, defects, charge doping, external electric field, periodic potential, in-plane uniaxial and biaxial stress, and out-of-plane long-range structural deformation, to name a few. This topical review explores structural, electronic and magnetic properties of Xenes and addresses the question of their functionalization in various ways, including external factors acting simultaneously. It also points to future directions to be explored in functionalization of Xenes. The results of experimental and theoretical studies obtained so far have many promising features making the 2D-Xene materials important players in the field of future nanoelectronics and spintronics.
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Affiliation(s)
- Mariusz Krawiec
- Institute of Physics, Maria Curie-Sklodowska University, Pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland
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7
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Sahoo MPK, Zhang Y, Wang J. Nanoscale magnetism and novel electronic properties of a bilayer bismuth(111) film with vacancies and chemical doping. Phys Chem Chem Phys 2018; 18:20550-61. [PMID: 27406933 DOI: 10.1039/c6cp03056d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetically doped topological insulators (TIs) exhibit several exotic phenomena including the magnetoelectric effect and quantum anomalous Hall effect. However, from an experimental perspective, incorporation of spin moment into 3D TIs is still challenging. Thus, instead of 3D TIs, the 2D form of TIs may open up new opportunities to induce magnetism. Based on first principles calculations, we demonstrate a novel strategy to realize robust magnetism and exotic electronic properties in a 2D TI [bilayer Bi(111) film: abbreviated as Bi(111)]. We examine the magnetic and electronic properties of Bi(111) with defects such as bismuth monovacancies (MVs) and divacancies (DVs), and these defects decorated with 3d transition metals (TMs). It has been observed that the MV in Bi(111) can induce novel half metallicity with a net magnetic moment of 1 μB. The origin of half metallicity and magnetism in MV/Bi(111) is further explained by the passivation of the σ-dangling bonds near the defect site. Furthermore, in spite of the nonmagnetic nature of DVs, the TMs (V, Cr, Mn, and Fe) trapped at the 5/8/5 defect structure of DVs can not only yield a much higher spin moment than those trapped at the MVs but also display intriguing electronic properties such as metallic, semiconducting and spin gapless semiconducting properties. The predicted magnetic and electronic properties of TM/DV/Bi(111) systems are explained through density of states, spin density distribution and Bader charge analysis.
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Affiliation(s)
- M P K Sahoo
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China. and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China and Department of Physics, RGUKT IIIT, Nuzvid Campus, Andhra Pradesh, India
| | - Yajun Zhang
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China.
| | - Jie Wang
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China. and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou 310007, China
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8
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Rakhmanova OR, Galashev AE. Motion of a lithium ion over a graphene–silicene channel: A computer model. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2017. [DOI: 10.1134/s003602441705020x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Li T, Su X, Li H, Ju W. Strong enhancement of spin–orbit splitting induced by σ–π coupling in Pb-decorated silicene. RSC Adv 2017. [DOI: 10.1039/c6ra28011k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electronic properties and spin–orbit (SO) splitting of silicene adsorbed with Cu, Ag, Au and Pb atoms at different coverages are investigated by means of first-principles calculations.
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Affiliation(s)
- Tongwei Li
- College of Physics and Engineering
- Henan University of Science and Technology
- Luoyang 471023
- China
| | - Xiangying Su
- College of Physics and Engineering
- Henan University of Science and Technology
- Luoyang 471023
- China
| | - Haisheng Li
- College of Physics and Engineering
- Henan University of Science and Technology
- Luoyang 471023
- China
| | - Weiwei Ju
- College of Physics and Engineering
- Henan University of Science and Technology
- Luoyang 471023
- China
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10
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Kong X, Liu Q, Zhang C, Peng Z, Chen Q. Elemental two-dimensional nanosheets beyond graphene. Chem Soc Rev 2017; 46:2127-2157. [DOI: 10.1039/c6cs00937a] [Citation(s) in RCA: 238] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The recent progress of elemental two-dimensional nanosheets, beyond graphene, has been summarized with the focus on their preparation and applications.
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Affiliation(s)
- Xiangkai Kong
- School of Physics and Electronic Information
- Huaibei Normal University
- Huaibei
- P. R. China
- High Magnetic Field Laboratory
| | - Qiangchun Liu
- School of Physics and Electronic Information
- Huaibei Normal University
- Huaibei
- P. R. China
| | - Changlin Zhang
- Joint Center for Artificial Photosynthesis
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - Zhenmeng Peng
- Department of Chemical and Biomolecular Engineering
- University of Akron
- Akron
- USA
| | - Qianwang Chen
- High Magnetic Field Laboratory
- Chinese Academy of Sciences
- Hefei
- P. R. China
- Hefei National Laboratory for Physical Science at Microscale and Department of Materials Science & Technology
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11
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Chowdhury S, Jana D. A theoretical review on electronic, magnetic and optical properties of silicene. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:126501. [PMID: 27753431 DOI: 10.1088/0034-4885/79/12/126501] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Inspired by the success of graphene, various two dimensional (2D) structures in free standing (FS) (hypothetical) form and on different substrates have been proposed recently. Silicene, a silicon counterpart of graphene, is predicted to possess massless Dirac fermions and to exhibit an experimentally accessible quantum spin Hall effect. Since the effective spin-orbit interaction is quite significant compared to graphene, buckling in silicene opens a gap of 1.55 meV at the Dirac point. This band gap can be further tailored by applying in plane stress, an external electric field, chemical functionalization and defects. In this topical theoretical review, we would like to explore the electronic, magnetic and optical properties, including Raman spectroscopy of various important derivatives of monolayer and bilayer silicene (BLS) with different adatoms (doping). The magnetic properties can be tailored by chemical functionalization, such as hydrogenation and introducing vacancy into the pristine planar silicene. Apart from some universal features of optical absorption present in all these 2D materials, the study on reflectivity modulation with doping (Al and P) concentration in silicene has indicated the emergence of some strong peaks having the robust characteristic of a doped reflective surface for both polarizations of the electromagnetic (EM) field. Besides this, attempts will be made to understand the electronic properties of silicene from some simple tight-binding Hamiltonian. We also point out the importance of shape dependence and optical anisotropy properties in silicene nanodisks and establish that a zigzag trigonal possesses the maximum magnetic moment. We also suggest future directions to be explored to make the synthesis of silicene and its various derivatives viable for verification of theoretical predictions. Although this is a fairly new route, the results obtained so far from experimental and theoretical studies in understanding silicene have shown enough significant promising features to open a new direction in the silicon industry, silicon based nano-structures in spintronics and in opto-electronic devices.
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Affiliation(s)
- Suman Chowdhury
- Department of Physics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700009, India
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12
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Ding N, Chen X, Wu CML. Mechanical properties and failure behaviors of the interface of hybrid graphene/hexagonal boron nitride sheets. Sci Rep 2016; 6:31499. [PMID: 27527371 PMCID: PMC4985750 DOI: 10.1038/srep31499] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/18/2016] [Indexed: 12/02/2022] Open
Abstract
Hybrid graphene/h-BN sheet has been fabricated recently and verified to possess unusual physical properties. During the growth process, defects such as vacancies are unavoidably present at the interface between graphene and h-BN. In the present work, typical vacancy defects, which were located at the interface between graphene and h-BN, were studied by density functional theory. The interface structure, mechanical and electronic properties, and failure behavior of the hybrid graphene/h-BN sheet were investigated and compared. The results showed that the formation energy of the defective graphene/h-BN interface basically increased with increasing inflection angles. However, Young's modulus for all graphene/h-BN systems studied decreased with the increase in inflection angles. The intrinsic strength of the hybrid graphene/h-BN sheets was affected not only by the inflection angles, but also by the type of interface connection and the type of defects. The energy band structure of the hybrid interface could be tuned by applying mechanical strain to the systems. These results demonstrated that vacancies introduced significant effects on the mechanical and electronic properties of the hybrid graphene/h-BN sheet.
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Affiliation(s)
- Ning Ding
- Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, PR China
- Shandong Academy of Sciences, Jinan, PR China
| | | | - Chi-Man Lawrence Wu
- Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, PR China
- Shandong Academy of Sciences, Jinan, PR China
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Yuan X, Lin G, Wang Y. Mechanical properties of armchair silicene nanoribbons with edge cracks: a molecular dynamics study. MOLECULAR SIMULATION 2016. [DOI: 10.1080/08927022.2016.1148266] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Xuebo Yuan
- Department of Aerospace Engineering and Mechanics, Harbin Institute of Technology, Harbin, P.R. China
| | - Guochang Lin
- Department of Aerospace Engineering and Mechanics, Harbin Institute of Technology, Harbin, P.R. China
| | - Youshan Wang
- Department of Aerospace Engineering and Mechanics, Harbin Institute of Technology, Harbin, P.R. China
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15
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Silicene nanomeshes: bandgap opening by bond symmetry breaking and uniaxial strain. Sci Rep 2016; 6:20971. [PMID: 26860967 PMCID: PMC4748269 DOI: 10.1038/srep20971] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/14/2016] [Indexed: 11/09/2022] Open
Abstract
Based on the first-principles calculations, we have investigated in detail the bandgap opening of silicene nanomeshes. Different to the mechanism of bandgap opening induced by the sublattice equivalence breaking, the method of degenerate perturbation through breaking the bond symmetry could split the π-like bands in the inversion symmetry preserved silicene nanomeshes, resulting into the πa1 − πa2 and πz1 − πz2 band sets with sizable energy intervals. Besides the bandgap opening in the nanomeshes with Dirac point being folded to Γ point, the split energy intervals are however apart away from Fermi level to leave the semimetal nature unchanged for the other nanomeshes with Dirac points located at opposite sides of Γ point as opposite pseudo spin wave valleys. A mass bandgap could be then opened at the aid of uniaxial strain to transfer the nanomesh to be semiconducting, whose width could be continuously enlarged until reaching its maximum Emax. Moreover, the Emax could also be tuned by controlling the defect density in silicene nanomeshes. These studies could contribute to the understanding of the bandgap engineering of silicene-based nanomaterials to call for further investigations on both theory and experiment.
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16
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Jiang QG, Wu WC, Zhang JF, Ao ZM, Wu YP, Huang HJ. Defections induced hydrogenation of silicene: a density functional theory calculation study. RSC Adv 2016. [DOI: 10.1039/c6ra11885b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Vacancy defects significantly depress the energy barrier for dissociative adsorption of H2 on silicene, which can open the band gap of silicene.
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Affiliation(s)
- Q. G. Jiang
- College of Mechanics and Materials
- Hohai University
- Nanjing 210098
- China
| | - W. C. Wu
- School of Materials Science and Engineering
- University of New South Wales
- Sydney
- Australia
| | - J. F. Zhang
- College of Mechanics and Materials
- Hohai University
- Nanjing 210098
- China
| | - Z. M. Ao
- Institute of Environmental Health and Pollution Control
- School of Environmental Science and Engineering
- Guangdong University of Technology
- Guangzhou
- China
| | - Y. P. Wu
- College of Mechanics and Materials
- Hohai University
- Nanjing 210098
- China
| | - H. J. Huang
- College of Mechanics and Materials
- Hohai University
- Nanjing 210098
- China
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17
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Defects in silicene: vacancy clusters, extended line defects, and Di-adatoms. Sci Rep 2015; 5:7881. [PMID: 25619941 PMCID: PMC4306108 DOI: 10.1038/srep07881] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/16/2014] [Indexed: 11/19/2022] Open
Abstract
Defects are almost inevitable during the fabrication process, and their existence strongly affects thermodynamic and (opto)electronic properties of two-dimensional materials. Very recent experiments have provided clear evidence for the presence of larger multi-vacancies in silicene, but their structure, stability, and formation mechanism remain largely unexplored. Here, we present a detailed theoretical study of silicene monolayer containing three types of defects: vacancy clusters, extended line defects (ELDs), and di-adatoms. First-principles calculations, along with ab initio molecular dynamics simulations, revealed the coalescence tendency of small defects and formation of highly stable vacancy clusters. The 5|8|5 ELD – the most favorable extended defect in both graphene and silicene sheets – is found to be easier to form in the latter case due to the mixed sp2/sp3 hybridization of silicon. In addition, hybrid functional calculations that contain part of the Hatree-Fock exchange energy demonstrated that the introduction of single and double silicon adatoms significantly enhances the stability of the system, and provides an effective approach on tuning the magnetic moment and band gap of silicene.
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Martins ADS, Veríssimo-Alves M. Group-IV nanosheets with vacancies: a tight-binding extended Hückel study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:365501. [PMID: 25132458 DOI: 10.1088/0953-8984/26/36/365501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this work, we present a theoretical study of the electronic properties of group-IV element nanosheets, namely graphene, silicene, germanene and the corresponding hydrogenated structures for the two latter, silicane and germanane. We compare the results of two different calculation methods, Density Functional Theory (DFT) and Extended Hückel Theory (EHT), for both pristine sheets and sheets of silicene and germanene with a single-atom vacancy. We show that EHT offers a remarkably reliable description of the electronic structure of these materials for all cases, thus offering an affordable way for studying large systems for which DFT calculations would be expensive and lengthy.
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Affiliation(s)
- Adriano de Souza Martins
- Departamento de Física, Instituto de Ciências Exatas, Universidade Federal Fluminense, Niterói, RJ, Brazil
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