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Kostov Gueorguiev, GueorguiORCID iD iconorcid.org/0000-0001-9402-1491
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Publikasjoner (10 av 42) Visa alla publikasjoner
Sangiovanni, D. G., Kostov Gueorguiev, G. & Kakanakova-Georgieva, A. (2018). Ab initio molecular dynamics of atomic-scale surface reactions: insights into metal organic chemical vapor deposition of AlN on graphene. Physical Chemistry, Chemical Physics - PCCP, 20(26), 17751-17761
Åpne denne publikasjonen i ny fane eller vindu >>Ab initio molecular dynamics of atomic-scale surface reactions: insights into metal organic chemical vapor deposition of AlN on graphene
2018 (engelsk)Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, nr 26, s. 17751-17761Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Metal organic chemical vapor deposition (MOCVD) of group III nitrides on graphene heterostructures offers new opportunities for the development of flexible optoelectronic devices and for the stabilization of conceptually-new two-dimensional materials. However, the MOCVD of group III nitrides is regulated by an intricate interplay of gas-phase and surface reactions that are beyond the resolution of experimental techniques. We use density-functional ab initio molecular dynamics (AIMD) with van der Waals corrections to identify atomistic pathways and associated electronic mechanisms driving precursor/surface reactions during metal organic vapor phase epitaxy at elevated temperatures of aluminum nitride on graphene, considered here as model case study. The results presented provide plausible interpretations of atomistic and electronic processes responsible for delivery of Al, C adatoms, and C-Al, CHx, AlNH2 admolecules on pristine graphene via precursor/surface reactions. In addition, the simulations reveal C adatom permeation across defect-free graphene, as well as exchange of C monomers with graphene carbon atoms, for which we obtain rates of approximate to 0.3 THz at typical experimental temperatures (1500 K), and extract activation energies Eexca = 0.28 +/- 0.13 eV and attempt frequencies A(exc) = 2.1 (x1.7(+/- 1)) THz via Arrhenius linear regression. The results demonstrate that AIMD simulations enable understanding complex precursor/surface reaction mechanisms, and thus propose AIMD to become an indispensable routine prediction-tool toward more effective exploitation of chemical precursors and better control of MOCVD processes during synthesis of functional materials.

sted, utgiver, år, opplag, sider
Royal Society of Chemistry, 2018
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-149847 (URN)10.1039/c8cp02786b (DOI)000437473300021 ()29915819 (PubMedID)
Merknad

Funding Agencies|Swedish Research Council (VR) through FLAG-ERA JTC project GRIFONE [VR 2015-06816, VR 2017-04071]; Olle Engkvist Foundation

Tilgjengelig fra: 2018-08-02 Laget: 2018-08-02 Sist oppdatert: 2019-06-28
Goyenola, C., Lai, C.-C., Näslund, L.-Å., Lu, J., Högberg, H., Hultman, L., . . . Gueorguiev, G. K. (2016). Theoretical prediction and synthesis of CSxFy thin films. The Journal of Physical Chemistry C, 120(17), 9527-9534
Åpne denne publikasjonen i ny fane eller vindu >>Theoretical prediction and synthesis of CSxFy thin films
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2016 (engelsk)Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, nr 17, s. 9527-9534Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A new carbon-based compound: CSxFy was addressed by density functional theory calculations and synthesized by reactive magnetron sputtering. Geometry optimizations and energy calculations were performed on graphene-like model systems containing sulfur and fluorine atoms. It is shown that [S+F] concentrations in the range of 0−10 at.%, structural ordered characteristics similar to graphene pieces containing ring defects are energetically feasible. The modeling predicts that CSxFy thin films with graphite and fullerene-like characteristics may be obtained for the mentioned concentration range. Accordingly, thin films were synthesized from a graphite solid target and sulfur hexafluoride as reactive gas. In agreement with the theoretical prediction, transmission electron microscopy characterization and selected area electron diffraction confirmed the presence of small ordered clusters with graphitic features in a sample containing 0.4 at.% of S and 3.4 at.% of F.

sted, utgiver, år, opplag, sider
American Chemical Society (ACS), 2016
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-121470 (URN)10.1021/acs.jpcc.6b02718 (DOI)000375631100060 ()
Merknad

funding agencies: Swedish Foundation for Strategic Research (SSF) [RMA11-0029]; Carl Trygger Foundation for Scientific Research; Swedish Research Council [642-2013-8020]; ERC [258509]; Knut and Alice Wallenberg Foundation; Swedish Government Strategic Research Area in Materials at Linkoping University 

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Tilgjengelig fra: 2015-09-21 Laget: 2015-09-21 Sist oppdatert: 2017-12-04bibliografisk kontrollert
Freitas, R. R., de Brito Mota, F., Rivelino, R., de Castilho, C. M., Kakanakova-Gueorguie, A. & Gueorguiev, G. K. (2016). Tuning band inversion symmetry of buckled III-Bi sheets by halogenation. Nanotechnology, 27(5), 1-11, Article ID 055704.
Åpne denne publikasjonen i ny fane eller vindu >>Tuning band inversion symmetry of buckled III-Bi sheets by halogenation
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2016 (engelsk)Inngår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 27, nr 5, s. 1-11, artikkel-id 055704Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

First-principles calculations are employed to investigate structural, electronic and topological insulating properties of XBi (X = B, Al, Ga, and In) monolayers upon halogenation. It is known that Y-XBi (X = Ga, In, Tl; Y = F, Cl, Br, I) can originate inversion-asymmetric topological insulators with large bulk band gaps. Our results suggest that Y-XBi (X = B, Al; Y = F, Cl, Br, I) may also result in nontrivial topological insulating phases. Despite the lower atomic number of B and Al, the spin-orbit coupling opens a band gap of about 400 meV in Y-XBi (X = B, Al), exhibiting an unusual electronic behavior for practical applications in spintronics. The nature of the bulk band gap and Dirac-cone edge states in their nanoribbons depends on the group-III elements and Y chemical species. They lead to a chemical tunability, giving rise to distinct band inversion symmetries and exhibiting Rashba-type spin splitting in the valence band of these systems. These findings indicate that a large family of Y-XBi sheets can exhibit nontrivial topological characteristics, by a proper tuning, and open a new possibility for viable applications at room temperature.

sted, utgiver, år, opplag, sider
IOP PUBLISHING LTD, 2016
Emneord
bismuth-based 2D materials; topological insulators; halogenation; spin-orbit coupling
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-125293 (URN)10.1088/0957-4484/27/5/055704 (DOI)000368894300018 ()26752271 (PubMedID)
Merknad

Funding Agencies|Swedish Research Council (VR) through the Swedish Research links project [348-2014-4249]; Linkoping Linnaeus Initiative for Novel Functionalized Materials (LiLi-NFM, VR); Swedish Foundation for Strategic Research (SSF) Synergy Grant on Functional Carbides and Advanced Surface Engineering (FUNCASE) [RMA11-0029]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Tilgjengelig fra: 2016-02-24 Laget: 2016-02-19 Sist oppdatert: 2017-11-30
dos Santos, R. B., de Brito Mota, F., Rivelino, R., Kakanakova-Gueorguie, A. & Gueorguiev, G. K. (2016). Van der Waals stacks of few-layer h-AlN with graphene: an ab initio study of structural, interaction and electronic properties. Nanotechnology, 27(14), 145601
Åpne denne publikasjonen i ny fane eller vindu >>Van der Waals stacks of few-layer h-AlN with graphene: an ab initio study of structural, interaction and electronic properties
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2016 (engelsk)Inngår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 27, nr 14, s. 145601-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Graphite-like hexagonal AlN (h-AlN) multilayers have been experimentally manifested and theoretically modeled. The development of any functional electronics applications of h-AlN would most certainly require its integration with other layered materials, particularly graphene. Here, by employing vdW-corrected density functional theory calculations, we investigate structure, interaction energy, and electronic properties of van der Waals stacking sequences of few-layer h-AlN with graphene. We find that the presence of a template such as graphene induces enough interlayer charge separation in h-AlN, favoring a graphite-like stacking formation. We also find that the interface dipole, calculated per unit cell of the stacks, tends to increase with the number of stacked layers of h-AlN and graphene.

sted, utgiver, år, opplag, sider
IOP PUBLISHING LTD, 2016
Emneord
2D materials beyond graphene; layered group-III nitrides; hexagonal AlN; van der Waals stacks; density functional theory
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-126239 (URN)10.1088/0957-4484/27/14/145601 (DOI)000371020700011 ()26902955 (PubMedID)
Merknad

Funding Agencies|Swedish Research Council (VR) through Swedish Research Links project [348-2014-4249, VR 621-2013-5818]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB)

Tilgjengelig fra: 2016-03-21 Laget: 2016-03-21 Sist oppdatert: 2018-03-21
Vinicius Da Costa Medeiros, P., Kostov Gueorguiev, G. & Stafström, S. (2015). Bonding, charge rearrangement and interface dipoles of benzene, graphene, and PAH molecules on Au(111) and Cu(111). Carbon, 81, 620-628
Åpne denne publikasjonen i ny fane eller vindu >>Bonding, charge rearrangement and interface dipoles of benzene, graphene, and PAH molecules on Au(111) and Cu(111)
2015 (engelsk)Inngår i: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 81, s. 620-628Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We perform a theoretical study of the electronic properties of polyaromatic hydrocarbon (PAH) molecules, as well as benzene and graphene, adsorbed on copper and gold. The PAH molecules studied are coronene (C24H12), circumcoronene (C54H18) and circumcircumcoronene (C96H24), which we consider as gradual approximations to an infinite graphene layer. In order to understand how the size of the adsorbed PAH molecules influences the adsorbate-metal interactions, we generalize the approach used in our earlier study [Phys Rev B, 85 (2012), p. 205423] to decompose the binding energies and net charge transfers into separate contributions from specific groups of atoms, and we then show that the zigzag edges of the PAH molecules interact stronger with the metal surfaces than the armchair ones. We discuss the nature of binding in our model systems as well as the formation of interface dipoles. We show that for all model systems studied here, the charge rearrangement contribution to the interface dipoles can be expressed as the product of the charge involved in the formation of the dipole and the distance between well-defined centers of charge for electron accumulation and depletion. This distance is only marginally dependent on the specific PAH molecules, decreasing slowly with their size.

sted, utgiver, år, opplag, sider
Elsevier, 2015
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-113164 (URN)10.1016/j.carbon.2014.09.096 (DOI)000345682900066 ()
Merknad

Funding Agencies|Swedish Research Council (VR); Linkoping Linnaeus Initiative on Novel Functionalized Materials (VR); Swedish Foundation for Strategic Research (SSF) [RMA11-0029]; FunMat (Functional Nanoscale Materials) - a VINN Excellence Centre (Swedish Agency for Innovation Systems VINNOVA)

Tilgjengelig fra: 2015-01-14 Laget: 2015-01-12 Sist oppdatert: 2017-12-05
dos Santos, R. B., Rivelino, R., de Brito Mota, F., Kostov Gueorguiev, G. & Kakanakova-Gueorguie, A. (2015). Dopant species with Al-Si and N-Si bonding in the MOCVD of AlN implementing trimethylaluminum, ammonia and silane. Journal of Physics D: Applied Physics, 48(29), Article ID 295104.
Åpne denne publikasjonen i ny fane eller vindu >>Dopant species with Al-Si and N-Si bonding in the MOCVD of AlN implementing trimethylaluminum, ammonia and silane
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2015 (engelsk)Inngår i: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 48, nr 29, artikkel-id 295104Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We have investigated gas-phase reactions driven by silane (SiH4), which is the dopant precursor in the metalorganic chemical vapor deposition (MOCVD) of aluminum nitride (AlN) doped by silicon, with prime focus on determination of the associated energy barriers. Our theoretical strategy is based on combining density-functional methods with minimum energy path calculations. The outcome of these calculations is suggestive for kinetically plausible and chemically stable reaction species with Al-Si bonding such as (CH3)(2)AlSiH3 and N-Si bonding such as H2NSiH3. Within this theoretical perspective, we propose a view of these reaction species as relevant for the actual MOCVD of Si-doped AlN, which is otherwise known to be contributed by the reaction species (CH3)(2)AlNH2 with Al-N bonding. By reflecting on experimental evidence in the MOCVD of various doped semiconductor materials, it is anticipated that the availability of dopant species with Al-Si, and alternatively N-Si bonding near the hot deposition surface, can govern the incorporation of Si atoms, as well as other point defects, at the AlN surface.

sted, utgiver, år, opplag, sider
IOP Publishing: Hybrid Open Access, 2015
Emneord
AlN; doping; MOCVD; ab initio calculations
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-120337 (URN)10.1088/0022-3727/48/29/295104 (DOI)000357604800009 ()
Merknad

Funding Agencies|Swedish Research Council (VR) (Swedish Research Links Project) [348-2014-4249]; Linkoping Linnaeus Initiative on Novel Functional Materials (VR); Swedish Governmental Agency for Innovation Systems (VINNOVA); Swedish Research Council (VR); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Tilgjengelig fra: 2015-07-31 Laget: 2015-07-31 Sist oppdatert: 2017-12-04
Freitas, R. R., Rivelino, R., Mota, F. d., Gueorguiev, G. K. & de Castilho, C. M. (2015). Energy Barrier Reduction for the Double Proton-Transfer Reaction in Guanine-Cytosine DNA Base Pair on a Gold Surface. The Journal of Physical Chemistry C, 119(27), 15735-15741
Åpne denne publikasjonen i ny fane eller vindu >>Energy Barrier Reduction for the Double Proton-Transfer Reaction in Guanine-Cytosine DNA Base Pair on a Gold Surface
Vise andre…
2015 (engelsk)Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, nr 27, s. 15735-15741Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We investigate, by means of first-principles calculations, the impact of a gold surface on the proton-transfer of the guanine-cytosine (GC) DNA base pair. Our calculations employ density functional improvements to correct van der Waals interactions and properly treat a weakly bound GC pair at an Au(111) surface. We adopted the simultaneous double proton-transfer (SDPT) mechanism proposed by Lowdin, which may lead to a spontaneous mutation in the structure of DNA from specific tautomerization involving the base pairs. Our calculated differences in the energetics and kinetics of the SDPT in the GC pair, when in contact with an inert gold surface, indicate a reduction of about 31% in the activation energy barrier of the GC/Au(111) tautomeric equilibrium. This finding gives strong evidence that tautomerism of DNA base pairs, binding to a noble surface, may be indeed relevant for the assessment of a possible point mutation, which could be induced by the presence of gold nanoparticles during DNA replication.

sted, utgiver, år, opplag, sider
American Chemical Society, 2015
Emneord
nucleobase tautomerization; nanotoxicology; van der Waals interactions; density functional theory; double proton-transfer; gold surface; mutation
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-120452 (URN)10.1021/acs.jpcc.5b04149 (DOI)000357964900104 ()
Merknad

Funding Agencies|Swedish Research Council (VR) [348-2014-4249]; Linkoping Linnaeus Initiative for Novel Functionalized Materials (LiLi-NFM, VR); Swedish Foundation for Strategic Research (SSF) [RMA11-0029]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Tilgjengelig fra: 2015-08-12 Laget: 2015-08-11 Sist oppdatert: 2017-12-04
dos Santos, R. B., Rivelino, R., de Brito Mota, F., Kakanakova-Gueorguie, A. & Gueorguiev, G. K. (2015). Feasibility of novel (H3C)(n)X(SiH3)(3-n) compounds (X = B, Al, Ga, In): structure, stability, reactivity, and Raman characterization from ab initio calculations. Dalton Transactions, 44(7), 3356-3366
Åpne denne publikasjonen i ny fane eller vindu >>Feasibility of novel (H3C)(n)X(SiH3)(3-n) compounds (X = B, Al, Ga, In): structure, stability, reactivity, and Raman characterization from ab initio calculations
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2015 (engelsk)Inngår i: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 44, nr 7, s. 3356-3366Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We employ ab initio calculations to predict the equilibrium structure, stability, reactivity, and Raman scattering properties of sixteen different (H3C)(n)X(SiH3)(3-n) compounds (X = B, Al, Ga, In) with n = 0-3. Among this methylsilylmetal family, only the (H3C)(3)X members, i.e., trimethylboron (TMB), trimethylaluminum (TMA), trimethylgallium (TMG), and trimethylindium (TMI), are currently well-studied. The remaining twelve compounds proposed here open up a two-dimensional array of new possibilities for precursors in various deposition processes, and evoke potential applications in the chemical synthesis of other compounds. We infer that within the (H3C)(n)X(SiH3)(3-n) family, the compounds with fewer silyl groups (and consequently with more methyl groups) are less reactive and more stable. This trend is verified from the calculated cohesive energy, Gibbs free energy of formation, bond strength, and global chemical indices. Furthermore, we propose sequential reaction routes for the synthesis of (H3C)(n)X(SiH3)(3-n) by substitution of methyl by silyl groups, where the silicon source is the silane gas. The corresponding reaction barriers for these chemical transformations lie in the usual energy range typical for MOCVD processes. We also report the Raman spectra and light scattering properties of the newly proposed (H3C)(n)X(SiH3)(3-n) compounds, in comparison with available data of known members of this family. Thus, our computational experiment provides useful information for a systematic understanding of the stability/reactivity and for the identification of these compounds.

sted, utgiver, år, opplag, sider
Royal Society of Chemistry, 2015
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-115338 (URN)10.1039/c4dt03406f (DOI)000349403100048 ()25599815 (PubMedID)
Merknad

Funding Agencies|Swedish Foundation for International Cooperation in Research and Higher Education (STINT) [YR2009-7017]; Swedish Research Council (VR) [348-2014-4249]; Linkoping Linnaeus Initiative on Novel Functionalized Materials (VR); Swedish Foundation for Strategic Research (SSF) Synergy on Functional Carbides and Advanced Surface Engineering (FUNCASE) [RMA-110029]; Swedish Governmental Agency for Innovation Systems (VINNOVA); Swedish Research Council (VR); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Fundacao de Ampar a Pesquisa do Estado da Bahia (FAPESB); Coordenacao de Aperfeicoamento de Pessoal de Novel Superior (CAPES)

Tilgjengelig fra: 2015-03-13 Laget: 2015-03-13 Sist oppdatert: 2017-12-04
Freitas, R. R. Q., de Brito Mota, F., Rivelino, R., de Castilho, C. M., Kakanakova-Georgieva, A. & Kostov Gueorguiev, G. (2015). Spin-orbit-induced gap modification in buckled honeycomb XBi and XBi3 (X = B, Al, Ga, and In) sheets. Journal of Physics: Condensed Matter, 27(48), 485306
Åpne denne publikasjonen i ny fane eller vindu >>Spin-orbit-induced gap modification in buckled honeycomb XBi and XBi3 (X = B, Al, Ga, and In) sheets
Vise andre…
2015 (engelsk)Inngår i: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 27, nr 48, s. 485306-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The band structure and stability of XBi and XBi3 (X = B, Al, Ga, and In) single sheets are predicted using first-principles calculations. It is demonstrated that the band gap values of these new classes of two-dimensional (2D) materials depend on both the spin-orbit coupling (SOC) and type of group-III elements in these hetero-sheets. Thus, topological properties can be achieved, allowing for viable applications based on coherent spin transport at room temperature. The spin-orbit effects are proved to be essential to explain the tunability by group-III atoms. A clear effect of including SOC in the calculations is lifting the spin degeneracy of the bands at the Gamma point of the Brillouin zone. The nature of the band gaps, direct or indirect, is also tuned by SOC, and by the appropriate X element involved. It is observed that, in the case of XBi single sheets, band inversions naturally occur for GaBi and InBi, which exhibit band gap values around 172 meV. This indicates that these 2D materials are potential candidates for topological insulators. On the contrary, a similar type of band inversion, as obtained for the XBi, was not observed in the XBi3 band structure. In general, the calculations, taking into account SOC, reveal that some of these buckled sheets exhibit sizable gaps, making them suitable for applications in room-temperature spintronic devices.

sted, utgiver, år, opplag, sider
Institute of Physics Publishing (IOPP), 2015
Emneord
bismuth; 2D materials; topological insulators; DFT; spin-orbit coupling
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-123752 (URN)10.1088/0953-8984/27/48/485306 (DOI)000365346900008 ()26569356 (PubMedID)
Merknad

Funding Agencies|Swedish Research Council (VR) [348-2014-4249]; Linkoping Linnaeus Initiative for Novel Functionalized Materials (LiLi-NFM, VR); Swedish Foundation for Strategic Research (SSF) Synergy on Functional Carbides and Advanced Surface Engineering (FUNCASE) [RMA11-0029]; ConselhoNacional de DesenvolvimentoCientifico e Tecnologico (CNPq); Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Tilgjengelig fra: 2016-01-11 Laget: 2016-01-11 Sist oppdatert: 2017-11-30bibliografisk kontrollert
Freitas, R. R. Q., Rivelino, R., Mota, F. d., Castilho, C. M., Kakanakova-Georgieva, A. & Gueorguiev, G. K. (2015). Topological Insulating Phases in Two-Dimensional Bismuth-Containing Single Layers Preserved by Hydrogenation. The Journal of Physical Chemistry C, 119(41), 23599-23606
Åpne denne publikasjonen i ny fane eller vindu >>Topological Insulating Phases in Two-Dimensional Bismuth-Containing Single Layers Preserved by Hydrogenation
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2015 (engelsk)Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, nr 41, s. 23599-23606Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Two-dimensional (2D) binary XBi compounds, where X belongs to group III elements (B, Al, Ga, and In), in a buckled honeycomb structure may originate sizable gap Z2 topological insulators (TIs). These are characterized by exhibiting single band inversion at the Γ point as well as nontrivial edge states in their corresponding nanoribbons. By using first-principles calculations, we demonstrate that hydrogenation of XBi single layers leads to distinct and stable crystal structures, which can preserve their topological insulating properties. Moreover, hydrogenation opens a band gap in this new class of 2D Z2 TIs, with distinct intensities, exhibiting an interesting electronic behavior for viable room-temperature applications of these 2D materials. The nature of the global band gap (direct or indirect) and topological insulating properties depend on the X element type and spatial configuration of the sheet, as well as the applied strain. Our results indicate that the geometric configuration can be crucial for preserving totally the topological characteristics of the hydrogenated sheets. We identify sizable band inversions in the band structure for the relaxed hydrogenated GaBi and InBi in their chairlike configurations and for hydrogenated BBi and AlBi under strain. Based on these findings, hydrogenation gives rise to a flexible chemical tunability and can preserve the band topology of the pristine XBi phases.

sted, utgiver, år, opplag, sider
American Chemical Society (ACS), 2015
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-123945 (URN)10.1021/acs.jpcc.5b07961 (DOI)000363068400036 ()
Tilgjengelig fra: 2016-01-14 Laget: 2016-01-14 Sist oppdatert: 2017-11-30bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0001-9402-1491