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Author Bafekry, A.; Stampfl, C.; Akgenc, B.; Mortazavi, B.; Ghergherehchi, M.; Nguyen, C.V.
Title Embedding of atoms into the nanopore sites of the C₆N₆ and C₆N₈ porous carbon nitride monolayers with tunable electronic properties Type A1 Journal article
Year 2020 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 22 Issue 11 Pages 6418-6433
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using first-principles calculations, we study the effect of embedding various atoms into the nanopore sites of both C6N6 and C6N8 monolayers. Our results indicate that the embedded atoms significantly affect the electronic and magnetic properties of C6N6 and C6N8 monolayers and lead to extraordinary and multifarious electronic properties, such as metallic, half-metallic, spin-glass semiconductor and dilute-magnetic semiconductor behaviour. Our results reveal that the H atom concentration dramatically affects the C6N6 monolayer. On increasing the H coverage, the impurity states also increase due to H atoms around the Fermi-level. C6N6 shows metallic character when the H atom concentration reaches 6.25%. Moreover, the effect of charge on the electronic properties of both Cr@C6N6 and C@C6N8 is also studied. Cr@C6N6 is a ferromagnetic metal with a magnetic moment of 2.40 mu(B), and when 0.2 electrons are added and removed, it remains a ferromagnetic metal with a magnetic moment of 2.57 and 2.77 mu(B), respectively. Interestingly, one can observe a semi-metal, in which the VBM and CBM in both spin channels touch each other near the Fermi-level. C@C6N8 is a semiconductor with a nontrivial band gap. When 0.2 electrons are removed, it remains metallic, and under excess electronic charge, it exhibits half-metallic behaviour.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000523409400037 Publication Date 2020-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited 17 Open Access
Notes ; This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2017R1A2B2011989). ; Approved Most recent IF: 3.3; 2020 IF: 4.123
Call Number UA @ admin @ c:irua:168617 Serial 6504
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Author Obeid, M.M.; Stampfl, C.; Bafekry, A.; Guan, Z.; Jappor, H.R.; Nguyen, C., V; Naseri, M.; Hoat, D.M.; Hieu, N.N.; Krauklis, A.E.; Tuan V Vu; Gogova, D.
Title First-principles investigation of nonmetal doped single-layer BiOBr as a potential photocatalyst with a low recombination rate Type A1 Journal article
Year 2020 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 22 Issue 27 Pages 15354-15364
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Nonmetal doping is an effective approach to modify the electronic band structure and enhance the photocatalytic performance of bismuth oxyhalides. Using density functional theory, we systematically examine the fundamental properties of single-layer BiOBr doped with boron (B) and phosphorus (P) atoms. The stability of the doped models is investigated based on the formation energies, where the substitutional doping is found to be energetically more stable under O-rich conditions than under Bi-rich ones. The results showed that substitutional doping of P atoms reduced the bandgap of pristine BiOBr to a greater extent than that of boron substitution. The calculation of the effective masses reveals that B doping can render the electrons and holes of pristine BiOBr lighter and heavier, respectively, resulting in a slower recombination rate of photoexcited electron-hole pairs. Based on the results of HOMO-LUMO calculations, the introduction of B atoms tends to increase the number of photocatalytically active sites. The top of the valence band and the conduction band bottom of the B doped BiOBr monolayer match well with the water redox potentials in an acidic environment. The absorption spectra propose that B(P) doping causes a red-shift. Overall, the results predict that nonmetal-doped BiOBr monolayers have a reduced bandgap, a slow recombination rate, more catalytically active sites, enhanced optical absorption edges, and reduced work functions, which will contribute to superior photocatalytic performance.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000549894000018 Publication Date 2020-06-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited 18 Open Access
Notes ; This work was partially supported by the financial support from the Natural Science Foundation of China (Grant No. 11904203) and the Fundamental Research Funds of Shandong University (Grant No. 2019GN065). ; Approved Most recent IF: 3.3; 2020 IF: 4.123
Call Number UA @ admin @ c:irua:171235 Serial 6522
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Author Bafekry, A.; Gogova, D.; M. Fadlallah, M.; V. Chuong, N.; Ghergherehchi, M.; Faraji, M.; Feghhi, S.A.H.; Oskoeian, M.
Title Electronic and optical properties of two-dimensional heterostructures and heterojunctions between doped-graphene and C- and N-containing materials Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 8 Pages 4865-4873
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electronic and optical properties of vertical heterostructures (HTSs) and lateral heterojunctions (HTJs) between (B,N)-codoped graphene (dop@Gr) and graphene (Gr), C3N, BC3 and h-BN monolayers are investigated using van der Waals density functional theory calculations. We have found that all the considered HTSs are energetically and thermally feasible at room temperature, and therefore they can be synthesized experimentally. The dop@Gr/Gr, BC3/dop@Gr and BN/dop@Gr HTSs are semiconductors with direct bandgaps of 0.1 eV, 80 meV and 1.23 eV, respectively, while the C3N/dop@Gr is a metal because of the strong interaction between dop@Gr and C3N layers. On the other hand, the dop@Gr-Gr and BN-dop@Gr HTJs are semiconductors, whereas the C3N-dop@Gr and BC3-dop@Gr HTJs are metals. The proposed HTSs can enhance the absorption of light in the whole wavelength range as compared to Gr and BN monolayers. The applied electric field or pressure strain changes the bandgaps of the HTSs and HTJs, indicating that these HTSs are highly promising for application in nanoscale multifunctional devices.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000625306100038 Publication Date 2021-02-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:177659 Serial 6986
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Author Bafekry, A.; Yagmurcukardes, M.; Akgenc, B.; Ghergherehchi, M.; Mortazavi, B.
Title First-principles investigation of electronic, mechanical and thermoelectric properties of graphene-like XBi (X = Si, Ge, Sn) monolayers Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 21 Pages 12471-12478
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Research progress on single layer group III monochalcogenides has been increasing rapidly owing to their interesting physics. Herein, we investigate the dynamically stable single layer forms of XBi (X = Ge, Si or Sn) using density functional theory calculations. Phonon band dispersion calculations and ab initio molecular dynamics simulations reveal the dynamical and thermal stability of the considered monolayers. Raman spectra calculations indicate the existence of 5 Raman active phonon modes, 3 of which are prominent and can be observed in possible Raman measurements. The electronic band structures of the XBi single layers were investigated with and without the effects of spin-orbit coupling (SOC). Our results show that XBi single layers show semiconducting properties with narrow band gap values without SOC. However, only single layer SiBi is an indirect band gap semiconductor, while GeBi and SnBi exhibit metallic behaviors when adding spin-orbit coupling effects. In addition, the calculated linear elastic parameters indicate the soft nature of the predicted monolayers. Moreover, our predictions for the thermoelectric properties of single layer XBi reveal that SiBi is a good thermoelectric material with increasing temperature. Overall, it is proposed that single layer XBi structures can be alternative, stable 2D single layers with varying electronic and thermoelectric properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000653851100001 Publication Date 2021-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:179007 Serial 6992
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Author Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Jappor, H.R.; Karbasizadeh, S.; Ghergherehchi, M.; Sarsari, I.A.; Ziabari, A.A.
Title Novel two-dimensional AlSb and InSb monolayers with a double-layer honeycomb structure : a first-principles study Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 34 Pages 18752-18759
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this work, motivated by the fabrication of an AlSb monolayer, we have focused on the electronic, mechanical and optical properties of AlSb and InSb monolayers with double-layer honeycomb structures, employing the density functional theory approach. The phonon band structure and cohesive energy confirm the stability of the XSb (X = Al and In) monolayers. The mechanical properties reveal that the XSb monolayers have a brittle nature. Using the GGA + SOC (HSE + SOC) functionals, the bandgap of the AlSb monolayer is predicted to be direct, while InSb has a metallic character using both functionals. We find that XSb (X = Al, In) two-dimensional bodies can absorb ultraviolet light. The present findings suggest several applications of AlSb and InSb monolayers in novel optical and electronic usages.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000686236800001 Publication Date 2021-08-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:181712 Serial 7005
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Author Chaney, G.; Cakir, D.; Peeters, F.M.; Ataca, C.
Title Stability of adsorption of Mg and Na on sulfur-functionalized MXenes Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 44 Pages 25424-25433
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Two-dimensional materials composed of transition metal carbides and nitrides (MXenes) are poised to revolutionize energy conversion and storage. In this work, we used density functional theory (DFT) to investigate the adsorption of Mg and Na adatoms on five M2CS2 monolayers (where M = Mo, Nb, Ti, V, and Zr) for battery applications. We assessed the stability of the adatom (i.e. Na and Mg)-monolayer systems by calculating adsorption and formation energies, as well as voltages as a function of surface coverage. For instance, we found that Mo2CS2 cannot support a full layer of Na nor even a single Mg atom. Na and Mg exhibit the strongest binding on Zr2CS2, followed by Ti2CS2, Nb2CS2 and V2CS2. Using the nudged elastic band method (NEB), we computed promising diffusion barriers for both dilute and nearly full ion surface coverage cases. In the dilute ion adsorption case, a single Mg and Na atom on Ti2CS2 experience similar to 0.47 eV and similar to 0.10 eV diffusion barriers between the lowest energy sites, respectively. For a nearly full surface coverage, a Na ion moving on Ti2CS2 experiences a similar to 0.33 eV energy barrier, implying a concentration-dependent diffusion barrier. Our molecular dynamics results indicate that the three (one) layers (layer) of the Mg (Na) ion on both surfaces of Ti2CS2 remain stable at T = 300 K. While, according to voltage calculations, Zr2CS2 can store Na up to three atomic layers, our MD simulations predict that the outermost layers detach from the Zr2CS2 monolayer due to the weak interaction between Na ions and the monolayer. This suggests that MD simulations are essential to confirm the stability of an ion-electrode system – an insight that is mostly absent in previous studies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000716024400001 Publication Date 2021-10-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 3 Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:184075 Serial 7020
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Author Nazar, N.D.; Vazifehshenas, T.; Ebrahimi, M.R.; Peeters, F.M.
Title Strong anisotropic optical properties of 8-Pmmn borophene : a many-body perturbation study Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 30 Pages 16417-16422
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using first-principles many-body perturbation theory, we investigate the optical properties of 8-Pmmn borophene at two levels of approximations; the GW method considering only the electron-electron interaction and the GW in combination with the Bethe-Salpeter equation including electron-hole coupling. The band structure exhibits anisotropic Dirac cones with semimetallic character. The optical absorption spectra are obtained for different light polarizations and we predict strong optical absorbance anisotropy. The absorption peaks undergo a global redshift when the electron-hole interaction is taken into account due to the formation of bound excitons which have an anisotropic excitonic wave function.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000677722700001 Publication Date 2021-07-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.123 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:180385 Serial 7022
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Author Faraji, M.; Bafekry, A.; Fadlallah, M.M.; Molaei, F.; Hieu, N.N.; Qian, P.; Ghergherehchi, M.; Gogova, D.
Title Surface modification of titanium carbide MXene monolayers (Ti₂C and Ti₃C₂) via chalcogenide and halogenide atoms Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 28 Pages 15319-15328
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Inspired by the recent successful growth of Ti2C and Ti3C2 monolayers, here, we investigate the structural, electronic, and mechanical properties of functionalized Ti2C and Ti3C2 monolayers by means of density functional theory calculations. The results reveal that monolayers of Ti2C and Ti3C2 are dynamically stable metals. Phonon band dispersion calculations demonstrate that two-surface functionalization of Ti2C and Ti(3)C(2)via chalcogenides (S, Se, and Te), halides (F, Cl, Br, and I), and oxygen atoms results in dynamically stable novel functionalized monolayer materials. Electronic band dispersions and density of states calculations reveal that all functionalized monolayer structures preserve the metallic nature of both Ti2C and Ti3C2 except Ti2C-O-2, which possesses the behavior of an indirect semiconductor via full-surface oxygen passivation. In addition, it is shown that although halide passivated Ti3C2 structures are still metallic, there exist multiple Dirac-like cones around the Fermi energy level, which indicates that semi-metallic behavior can be obtained upon external effects by tuning the energy of the Dirac cones. In addition, the computed linear-elastic parameters prove that functionalization is a powerful tool in tuning the mechanical properties of stiff monolayers of bare Ti2C and Ti3C2. Our study discloses that the electronic and structural properties of Ti2C and Ti3C2 MXene monolayers are suitable for surface modification, which is highly desirable for material property engineering and device integration.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000672406800001 Publication Date 2021-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:179809 Serial 7027
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Author Naseri, M.; Bafekry, A.; Faraji, M.; Hoat, D.M.; Fadlallah, M.M.; Ghergherehchi, M.; Sabbaghi, N.; Gogova, D.
Title Two-dimensional buckled tetragonal cadmium chalcogenides including CdS, CdSe, and CdTe monolayers as photo-catalysts for water splitting Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 21 Pages 12226-12232
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Pure hydrogen production via water splitting is an ideal strategy for producing clean and sustainable energy. Two-dimensional (2D) cadmium chalcogenide single-layers with a tetragonal crystal structure, namely Tetra-CdX (X = S, Se, and Te) monolayers, are theoretically predicted by means of density functional theory (DFT). Their structural stability and electronic and optical properties are investigated. We find that Tetra-CdX single-layers are thermodynamically stable. Their stability decreases as we go down the 6A group in the periodic table, i.e., from X = S to Se, and Te which also means that the electronegativity decreases. All considered novel monolayers are indirect band gap semiconductors. Using the HSE06 functional the electronic band gaps of CdS, CdSe, and CdTe monolayers are predicted to be 3.10 eV, 2.97 eV, and 2.90 eV, respectively. The impact of mechanical strain on the physical properties was studied, which indicates that compressive strain increases the band gap and tensile strain decreases the band gap. The optical properties of the Tetra-CdX monolayers show the ability of these monolayers to absorb visible light. Due to the suitable band gaps and band edge positions of Tetra-CdX, these newly discovered 2D materials are promising for photocatalytic water splitting.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000651904600001 Publication Date 2021-04-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:178378 Serial 7041
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Author Bafekry, A.; Karbasizadeh, S.; Stampfl, C.; Faraji, M.; Hoat, D.M.; Sarsari, I.A.; Feghhi, S.A.H.; Ghergherehchi, M.
Title Two-dimensional Janus semiconductor BiTeCl and BiTeBr monolayers : a first-principles study on their tunable electronic properties via an electric field and mechanical strain Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 28 Pages 15216-15223
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Motivated by the recent successful synthesis of highly crystalline ultrathin BiTeCl and BiTeBr layered sheets [Debarati Hajra et al., ACS Nano, 2020, 14, 15626], herein for the first time, we carry out a comprehensive study on the structural and electronic properties of BiTeCl and BiTeBr Janus monolayers using density functional theory (DFT) calculations. Different structural and electronic parameters including the lattice constant, bond lengths, layer thickness in the z-direction, different interatomic angles, work function, charge density difference, cohesive energy and Rashba coefficients are determined to acquire a deep understanding of these monolayers. The calculations show good stability of the studied single layers. BiTeCl and BiTeBr monolayers are semiconductors with electronic bandgaps of 0.83 and 0.80 eV, respectively. The results also show that the semiconductor-metal transformation can be induced by increasing the number of layers. In addition, the engineering of the electronic structure is also studied by applying an electric field, and mechanical uniaxial and biaxial strain. The results show a significant change of the bandgaps and that an indirect-direct band-gap transition can be induced. This study highlights the positive prospect for the application of BiTeCl and BiTeBr layered sheets in novel electronic and energy conversion systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000670553900001 Publication Date 2021-06-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:179827 Serial 7042
Permanent link to this record
 

 
Author Baskurt, M.; Nair, R.R.; Peeters, F.M.; Sahin, H.
Title Ultra-thin structures of manganese fluorides : conversion from manganese dichalcogenides by fluorination Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 17 Pages 10218-10224
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this study, it is predicted by density functional theory calculations that graphene-like novel ultra-thin phases of manganese fluoride crystals, that have nonlayered structures in their bulk form, can be stabilized by fluorination of manganese dichalcogenide crystals. First, it is shown that substitution of fluorine atoms with chalcogens in the manganese dichalcogenide host lattice is favorable. Among possible crystal formations, three stable ultra-thin structures of manganese fluoride, 1H-MnF2, 1T-MnF2 and MnF3, are found to be stable by total energy optimization calculations. In addition, phonon calculations and Raman activity analysis reveal that predicted novel single-layers are dynamically stable crystal structures displaying distinctive characteristic peaks in their vibrational spectrum enabling experimental determination of the corresponding phases. Differing from 1H-MnF2 antiferromagnetic (AFM) large gap semiconductor, 1T-MnF2 and MnF3 single-layers are semiconductors with ferromagnetic (FM) ground state.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000641719700001 Publication Date 2021-04-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 1 Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:178252 Serial 7043
Permanent link to this record
 

 
Author Sozen, Y.; Yagmurcukardes, M.; Sahin, H.
Title Vibrational and optical identification of GeO₂ and GeO single layers : a first-principles study Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 37 Pages 21307-21315
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In the present work, the identification of two hexagonal phases of germanium oxides (namely GeO2 and GeO) through the vibrational and optical properties is reported using density functional theory calculations. While structural optimizations show that single-layer GeO2 and GeO crystallize in 1T and buckled phases, phonon band dispersions reveal the dynamical stability of each structure. First-order off-resonant Raman spectral predictions demonstrate that each free-standing single-layer possesses characteristic peaks that are representative for the identification of the germanium oxide phase. On the other hand, electronic band dispersion analysis shows the insulating and large-gap semiconducting nature of single-layer GeO2 and GeO, respectively. Moreover, optical absorption, reflectance, and transmittance spectra obtained by means of G(0)W(0)-BSE calculations reveal the existence of tightly bound excitons in each phase, displaying strong optical absorption. Furthermore, the excitonic gaps are found to be at deep UV and visible portions of the spectrum, for GeO2 and GeO crystals, with energies of 6.24 and 3.10 eV, respectively. In addition, at the prominent excitonic resonances, single-layers display high reflectivity with a zero transmittance, which is another indication of the strong light-matter interaction inside the crystal medium.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000697364300001 Publication Date 2021-09-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:181571 Serial 7044
Permanent link to this record
 

 
Author Demirkol, Ö.; Sevik, C.; Demiroğlu, I.
Title First principles assessment of the phase stability and transition mechanisms of designated crystal structures of pristine and Janus transition metal dichalcogenides Type A1 Journal article
Year 2022 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 24 Issue 12 Pages 7430-7441
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Two-dimensional Transition Metal Dichalcogenides (TMDs) possessing extraordinary physical properties at reduced dimensionality have attracted interest due to their promise in electronic and optical device applications. However, TMD monolayers can show a broad range of different properties depending on their crystal phase; for example, H phases are usually semiconductors, while the T phases are metallic. Thus, controlling phase transitions has become critical for device applications. In this study, the energetically low-lying crystal structures of pristine and Janus TMDs are investigated by using ab initio Nudged Elastic Band and molecular dynamics simulations to provide a general explanation for their phase stability and transition properties. Across all materials investigated, the T phase is found to be the least stable and the H phase is the most stable except for WTe2, while the T' and T '' phases change places according to the TMD material. The transition energy barriers are found to be large enough to hint that even the higher energy phases are unlikely to undergo a phase transition to a more stable phase if they can be achieved except for the least stable T phase, which has zero barrier towards the T ' phase. Indeed, in molecular dynamics simulations the thermodynamically least stable T phase transformed into the T ' phase spontaneously while in general no other phase transition was observed up to 2100 K for the other three phases. Thus, the examined T ', T '' and H phases were shown to be mostly stable and do not readily transform into another phase. Furthermore, so-called mixed phase calculations considered in our study explain the experimentally observed lateral hybrid structures and point out that the coexistence of different phases is strongly stable against phase transitions. Indeed, stable complex structures such as metal-semiconductor-metal architectures, which have immense potential to be used in future device applications, are also possible based on our investigation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000766791000001 Publication Date 2022-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.3
Call Number UA @ admin @ c:irua:187184 Serial 7164
Permanent link to this record
 

 
Author Yorulmaz, U.; Šabani, D.; Yagmurcukardes, M.; Sevik, C.; Milošević, M.V.
Title High-throughput analysis of tetragonal transition metal Xenes Type A1 Journal article
Year 2022 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 24 Issue 48 Pages 29406-29412
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We report a high-throughput first-principles characterization of the structural, mechanical, electronic, and vibrational properties of tetragonal single-layer transition metal Xenes (t-TMXs). Our calculations revealed 22 dynamically, mechanically and chemically stable structures among the 96 possible free-standing layers present in the t-TMX family. As a fingerprint for their structural identification, we identified four characteristic Raman active phonon modes, namely three in-plane and one out-of-plane optical branches, with various intensities and frequencies depending on the material in question. Spin-polarized electronic calculations demonstrated that anti-ferromagnetic (AFM) metals, ferromagnetic (FM) metals, AFM semiconductors, and non-magnetic semiconductor materials exist within this family, evidencing the potential of t-TMXs for further use in multifunctional heterostructures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000892446100001 Publication Date 2022-11-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited 1 Open Access Not_Open_Access
Notes Approved Most recent IF: 3.3
Call Number UA @ admin @ c:irua:192762 Serial 7310
Permanent link to this record
 

 
Author Vermeyen, T.; Brence, J.; Van Echelpoel, R.; Aerts, R.; Acke, G.; Bultinck, P.; Herrebout, W.
Title Exploring machine learning methods for absolute configuration determination with vibrational circular dichroism Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 35 Pages 19781-19789
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Molecular Spectroscopy (MolSpec)
Abstract The added value of supervised Machine Learning (ML) methods to determine the Absolute Configuration (AC) of compounds from their Vibrational Circular Dichroism (VCD) spectra was explored. Among all ML methods considered, Random Forest (RF) and Feedforward Neural Network (FNN) yield the best performance for identification of the AC. At its best, FNN allows near-perfect AC determination, with accuracy of prediction up to 0.995, while RF combines good predictive accuracy (up to 0.940) with the ability to identify the spectral areas important for the identification of the AC. No loss in performance of either model is observed as long as the spectral sampling interval used does not exceed the spectral bandwidth. Increasing the sampling interval proves to be the best method to lower the dimensionality of the input data, thereby decreasing the computational cost associated with the training of the models.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000691366500001 Publication Date 2021-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:180290 Serial 7951
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Author Duran, T.A.; Šabani, D.; Milošević, M.V.; Sahin, H.
Title Experimental and theoretical investigation of synthesis and properties of dodecanethiol-functionalized MoS₂ Type A1 Journal article
Year 2023 Publication Physical chemistry, chemical physics Abbreviated Journal
Volume 25 Issue 40 Pages 27141-27150
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Herein, we investigate the DDT (1-dodecanethiol) functionalization of exfoliated MoS2 by using experimental and theoretical tools. For the functionalization of MoS2, DDT treatment was incorporated into the conventional NMP (N-methyl pyrrolidone) exfoliation procedure. Afterward, it has been demonstrated that the functionalization process is successful through optical, morphological and theoretical analysis. The D, G and 2LA peaks seen in the Raman spectrum of exfoliated NMP-MoS2 particles, indicate the formation of graphitic species on MoS2 sheets. In addition, as the DDT ratio increases, the vacant sites on MoS2 sheets diminish. Moreover, at an optimized ratio of DDT-NMP, the maximum number of graphitic quantum dots (GQDs) is observed on MoS2 nanosheets. Specifically, the STEM and AFM data confirm that GQDs reside on the MoS2 nano-sheets and also that the particle size of the DDT-MoS2 is mostly fixed, while the NMP-MoS2 show many smaller and distributed sizes. The comparison of PL intensities of the NMP-MoS2 and DDT-MoS2 samples states a 10-fold increment is visible, and a 60-fold increment in NIR region photoluminescent properties. Moreover, our results lay out understanding and perceptions on the surface and edge chemistry of exfoliated MoS2 and open up more opportunities for MoS2 and GQD particles with broader applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001076998800001 Publication Date 2023-09-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.3 Times cited Open Access
Notes Approved Most recent IF: 3.3; 2023 IF: 4.123
Call Number UA @ admin @ c:irua:200284 Serial 9033
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Author Dong, H.M.; Liang, H.P.; Tao, Z.H.; Duan, Y.F.; Milošević, M.V.; Chang, K.
Title Interface thermal conductivities induced by van der Waals interactions Type A1 Journal article
Year 2024 Publication Physical chemistry, chemical physics Abbreviated Journal
Volume 26 Issue 5 Pages 4047-4051
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The interface heat transfer of two layers induced by van der Waals (vdW) contacts is theoretically investigated, based on first-principles calculations at low temperatures. The results suggest that out-of-plane acoustic phonons with low frequencies dominate the interface thermal transport due to the vdW interaction. The interface thermal conductivity is proportional to the cubic of temperature at very low temperatures, but becomes linearly proportional to temperature as temperature increases. We show that manipulating the strain alters vdW coupling, leading to increased interfacial thermal conductivity at the interface. Our findings provide valuable insights into the interface heat transport in vdW heterostructures and support further design and optimization of electronic and optoelectronic nanodevices based on vdW contacts. The heat transfer induced by van der Waals contacts is dominated by ZA phonons. The interface thermal conductivity is proportional to the cubic of temperature, but becomes linearly proportional to temperature as temperature increases.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001142323400001 Publication Date 2024-01-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record
Impact Factor 3.3 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.3; 2024 IF: 4.123
Call Number UA @ admin @ c:irua:202795 Serial 9050
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Author Gogoi, A.; Neyts, E.C.; Peeters, F.M.
Title Reduction-enhanced water flux through layered graphene oxide (GO) membranes stabilized with H3O+ and OH- ions Type A1 Journal article
Year 2024 Publication Physical chemistry, chemical physics Abbreviated Journal
Volume 26 Issue 13 Pages 10265-10272
Keywords A1 Journal article; Condensed Matter Theory (CMT); Modelling and Simulation in Chemistry (MOSAIC)
Abstract Graphene oxide (GO) is one of the most promising candidates for next generation of atomically thin membranes. Nevertheless, one of the major issues for real world application of GO membranes is their undesirable swelling in an aqueous environment. Recently, we demonstrated that generation of H3O+ and OH- ions (e.g., with an external electric field) in the interlayer gallery could impart aqueous stability to the layered GO membranes (A. Gogoi, ACS Appl. Mater. Interfaces, 2022, 14, 34946). This, however, compromises the water flux through the membrane. In this study, we report on reducing the GO nanosheets as a solution to this issue. With the reduction of the GO nanosheets, the water flux through the layered GO membrane initially increases and then decreases again beyond a certain degree of reduction. Here, two key factors are at play. Firstly, the instability of the H-bond network between water molecules and the GO nanosheets, which increases the water flux. Secondly, the pore size reduction in the interlayer gallery of the membranes, which decreases the water flux. We also observe a significant improvement in the salt rejection of the membranes, due to the dissociation of water molecules in the interlayer gallery. In particular, for the case of 10% water dissociation, the water flux through the membranes can be enhanced without altering its selectivity. This is an encouraging observation as it breaks the traditional tradeoff between water flux and salt rejection of a membrane.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001186465400001 Publication Date 2024-03-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:204792 Serial 9168
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Author Houssa, M.; van den Broek, B.; Scalise, E.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title An electric field tunable energy band gap at silicene/(0001) ZnS interfaces Type A1 Journal article
Year 2013 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 15 Issue 11 Pages 3702-3705
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The interaction of silicene, the silicon counterpart of graphene, with (0001) ZnS surfaces is investigated theoretically, using first-principles simulations. The charge transfer occurring at the silicene/(0001) ZnS interface leads to the opening of an indirect energy band gap of about 0.7 eV in silicene. Remarkably, the nature (indirect or direct) and magnitude of the energy band gap of silicene can be controlled by an external electric field: the energy gap is predicted to become direct for electric fields larger than about 0.5 V angstrom(-1), and the direct energy gap decreases approximately linearly with the applied electric field. The predicted electric field tunable energy band gap of the silicene/(0001) ZnS interface is very promising for its potential use in nanoelectronic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000315165100002 Publication Date 2013-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 74 Open Access
Notes Approved Most recent IF: 4.123; 2013 IF: 4.198
Call Number UA @ lucian @ c:irua:107702 Serial 94
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Author Çakir, D.; Sahin, H.; Peeters, F.M.
Title Doping of rhenium disulfide monolayers : a systematic first principles study Type A1 Journal article
Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 31 Pages 16771-16779
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The absence of a direct-to-indirect band gap transition in ReS2 when going from the monolayer to bulk makes it special among the other semiconducting transition metal dichalcogenides. The functionalization of this promising layered material emerges as a necessity for the next generation technological applications. Here, the structural, electronic, and magnetic properties of substitutionally doped ReS2 monolayers at either the S or Re site were systematically studied by using first principles density functional calculations. We found that substitutional doping of ReS2 depends sensitively on the growth conditions of ReS2. Among the large number of non-metallic atoms, namely H, B, C, Se, Te, F, Br, Cl, As, P. and N, we identified the most promising candidates for n-type and p-type doping of ReS2. While Cl is an ideal candidate for n-type doping, P appears to be the most promising candidate for p-type doping of the ReS2 monolayer. We also investigated the doping of ReS2 with metal atoms, namely Mo, W, Ti, V. Cr, Co, Fe, Mn, Ni, Cu, Nb, Zn, Ru, Os and Pt. Mo, Nb, Ti, and V atoms are found to be easily incorporated in a single layer of ReS2 as substitutional impurities at the Re site for all growth conditions considered in this work. Tuning chemical potentials of dopant atoms energetically makes it possible to dope ReS2 with Fe, Co, Cr, Mn, W, Ru, and Os at the Re site. We observe a robust trend for the magnetic moments when substituting a Re atom with metal atoms such that depending on the electronic configuration of dopant atoms, the net magnetic moment of the doped ReS2 becomes either 0 or 1 mu(B). Among the metallic dopants, Mo is the best candidate for p-type doping of ReS2 owing to its favorable energetics and promising electronic properties.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000340075700048 Publication Date 2014-07-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 58 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus-long Marie Curie Fellowship. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. ; Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:118742 Serial 752
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Author Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D.; Volety, K.; Huyberechts, G.; Paul, J.
Title High throughput first-principles calculations of bixbyite oxides for TCO applications Type A1 Journal article
Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 33 Pages 17724-17733
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We present a high-throughput computing scheme based on density functional theory (DFT) to generate a class of oxides and screen them with the aim of identifying those that might be electronically appropriate for transparent conducting oxide (TCO) applications. The screening criteria used are a minimum band gap to ensure sufficient transparency, a band edge alignment consistent with easy n- or p-type dopability, and a minimum thermodynamic phase stability to be experimentally synthesizable. Following this scheme we screened 23 binary and 1518 ternary bixbyite oxides in order to identify promising candidates, which can then be a subject of an in-depth study. The results for the known TCOs are in good agreement with the reported data in the literature. We suggest a list of several new potential TCOs, including both n- and p-type compounds.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000341064800041 Publication Date 2014-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 23 Open Access
Notes ; We gratefully acknowledge financial support from the IWT-Vlaanderen through the ISIMADE project (IWT-n 080023), the FWO-Vlaanderen through project G.0150.13 and a GOA fund from the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation and the Flemish Government (EWI Department). ; Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:118263 Serial 1469
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Author Neyts, E.; Bogaerts, A.
Title Influence of internal energy and impact angle on the sticking behaviour of reactive radicals in thin a-C:H film growth: a molecular dynamics study Type A1 Journal article
Year 2006 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 8 Issue 17 Pages 2066-2071
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000236970300011 Publication Date 2006-03-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 7 Open Access
Notes Approved Most recent IF: 4.123; 2006 IF: 2.892
Call Number UA @ lucian @ c:irua:57353 Serial 1625
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Author Ahenach, J.; Cool, P.; Vansant, E.F.; Lebedev, O.; van Landuyt, J.
Title Influence of water on the pillaring of montmorillonite with aminopropyltriethoxysilane Type A1 Journal article
Year 1999 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 1 Issue Pages 3703-3708
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000081765300046 Publication Date 2002-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 10 Open Access
Notes Approved Most recent IF: 4.123; 1999 IF: NA
Call Number UA @ lucian @ c:irua:28250 Serial 1660
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Author Aerts, A.; Follens, L.R.A.; Biermans, E.; Bals, S.; Van Tendeloo, G.; Loppinet, B.; Kirschhock, C.E.A.; Martens, J.A.
Title Modelling of synchrotron SAXS patterns of silicalite-1 zeolite during crystallization Type A1 Journal article
Year 2011 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 13 Issue 10 Pages 4318-4325
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Synchrotron small angle X-ray scattering (SAXS) was used to characterize silicalite-1 zeolite crystallization from TEOS/TPAOH/water clear sol. SAXS patterns were recorded over a broad range of length scales, enabling the simultaneous monitoring of nanoparticles and crystals occurring at various stages of the synthesis. A simple two-population model accurately described the patterns. Nanoparticles were modeled by polydisperse coreshell spheres and crystals by monodisperse oblate ellipsoids. These models were consistent with TEM images. The SAXS results, in conjunction with in situ light scattering, showed that nucleation of crystals occurred in a short period of time. Crystals were uniform in size and shape and became increasingly anisotropic during growth. In the presence of nanoparticles, crystal growth was fast. During crystal growth, the number of nanoparticles decreased gradually but their size was constant. These observations suggested that the nanoparticles were growth units in an aggregative crystal growth mechanism. Crystals grown in the presence of nanoparticles developed a faceted habit and intergrowths. In the final stages of growth, nanoparticles were depleted. Concurrently, the crystal growth rate decreased significantly.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000287584700017 Publication Date 2011-01-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 22 Open Access
Notes Fwo; Iap; Esteem 026019 Approved Most recent IF: 4.123; 2011 IF: 3.573
Call Number UA @ lucian @ c:irua:87602 Serial 2155
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Author Bekaert, J.; Saniz, R.; Partoens, B.; Lamoen, D.
Title Native point defects in CuIn1-xGaxSe2 : hybrid density functional calculations predict the origin of p- and n-type conductivity Type A1 Journal article
Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 40 Pages 22299-22308
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We have performed a first-principles study of the p- and n-type conductivity in CuIn1−xGaxSe2 due to native point defects, based on the HSE06 hybrid functional. Band alignment shows that the band gap becomes larger with x due to the increasing conduction band minimum, rendering it hard to establish n-type conductivity in CuGaSe2. From the defect formation energies, we find that In/GaCu is a shallow donor, while VCu, VIn/Ga and CuIn/Ga act as shallow acceptors. Using the total charge neutrality of ionized defects and intrinsic charge carriers to determine the Fermi level, we show that under In-rich growth conditions InCu causes strongly n-type conductivity in CuInSe2. Under increasingly In-poor growth conditions, the conductivity type in CuInSe2 alters to p-type and compensation of the acceptors by InCu reduces, as also observed in photoluminescence experiments. In CuGaSe2, the native acceptors pin the Fermi level far away from the conduction band minimum, thus inhibiting n-type conductivity. On the other hand, CuGaSe2 shows strong p-type conductivity under a wide range of Ga-poor growth conditions. Maximal p-type conductivity in CuIn1−xGaxSe2 is reached under In/Ga-poor growth conditions, in agreement with charge concentration measurements on samples with In/Ga-poor stoichiometry, and is primarily due to the dominant acceptor CuIn/Ga.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000343072800042 Publication Date 2014-09-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 43 Open Access
Notes ; We gratefully acknowledge financial support from the science fund FWO-Flanders through project G.0150.13. The first-principles calculations have been carried out on the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Centre (VSC), supported financially by the Hercules foundation and the Flemish Government (EWI Department). We also like to thank Prof. S. Siebentritt of the University of Luxembourg for a presentation of her work on GIGS during a visit to our research group and for helpful discussions of our results. ; Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:120465 Serial 2284
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Author Verberck, B.; Okazaki, T.; Tarakina, N.V.
Title Ordered and disordered packing of coronene molecules in carbon nanotubes Type A1 Journal article
Year 2013 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 15 Issue 41 Pages 18108-18114
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Monte Carlo simulations of coronene molecules in single-walled carbon nanotubes (SWCNTs) and dicoronylene molecules in SWCNTs are performed. Depending on the diameter D of the encapsulating SWCNT, regimes favoring the formation of ordered, one-dimensional (1D) stacks of tilted molecules (D <= 1.7 nm for coronene@SWCNT, 1.5 nm <= D <= 1.7 nm for dicoronylene@SWCNT) and regimes with disordered molecular arrangements and increased translational mobilities enabling the thermally induced polymerization of neighboring molecules resulting in the formation of graphene nanoribbons (GNRs) are observed. The results show that the diameter of the encapsulating nanotube is a crucial parameter for the controlled synthesis of either highly ordered 1D structures or GNR precursors.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000325400600045 Publication Date 2013-09-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 9 Open Access
Notes ; B.V. is a Postdoctoral Fellow of the Research Foundation Flanders (FWO-VI). N.V.T. acknowledges funding by the Bavarian Ministry of Sciences, Research and the Arts. ; Approved Most recent IF: 4.123; 2013 IF: 4.198
Call Number UA @ lucian @ c:irua:112212 Serial 2502
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Author Amini, M.N.; Dixit, H.; Saniz, R.; Lamoen, D.; Partoens, B.
Title The origin of p-type conductivity in ZnM2O4 (M = Co, Rh, Ir) spinels Type A1 Journal article
Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 6 Pages 2588-2596
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract ZnM2O4 (M = Co, Rh, Ir) spinels are considered as a class of potential p-type transparent conducting oxides (TCOs). We report the formation energy of acceptor-like defects using first principles calculations with an advanced hybrid exchange-correlation functional (HSE06) within density functional theory (DFT). Due to the discrepancies between the theoretically obtained band gaps with this hybrid functional and the – scattered – experimental results, we also perform GW calculations to support the validity of the description of these spinels with the HSE06 functional. The considered defects are the cation vacancy and antisite defects, which are supposed to be the leading source of disorder in the spinel structures. We also discuss the band alignments in these spinels. The calculated formation energies indicate that the antisite defects ZnM (Zn replacing M, M = Co, Rh, Ir) and VZn act as shallow acceptors in ZnCo2O4, ZnRh2O4 and ZnIr2O4, which explains the experimentally observed p-type conductivity in those systems. Moreover, our systematic study indicates that the ZnIr antisite defect has the lowest formation energy in the group and it corroborates the highest p-type conductivity reported for ZnIr2O4 among the group of ZnM2O4 spinels. To gain further insight into factors affecting the p-type conductivity, we have also investigated the formation of localized small polarons by calculating the self-trapping energy of the holes.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000329926700040 Publication Date 2013-12-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 47 Open Access
Notes Fwo; Goa; Hercules Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:114829 Serial 2525
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Author Sliem, M.A.; Turner, S.; Heeskens, D.; Kalidindi, S.B.; Van Tendeloo, G.; Muhler, M.; Fischer, R.A.
Title Preparation, microstructure characterization and catalytic performance of Cu/ZnO and ZnO/Cu composite nanoparticles for liquid phase methanol synthesis Type A1 Journal article
Year 2012 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 14 Issue 22 Pages 8170-8178
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Stearate@Cu/ZnO nanocomposite particles with molar ratios of ZnO ∶ Cu = 2 and 5 are synthesized by reduction of the metalorganic Cu precursor [Cu{(OCH(CH3)CH2N(CH3)2)}2] in the presence of stearate@ZnO nanoparticles. In the case of ZnO ∶ Cu = 5, high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) combined with electron-energy-loss-spectroscopy (EELS) as well as attenuated total reflection Fourier transform infrared (ATR-IR) spectroscopy are used to localize the small amount of Cu deposited on the surface of 35 nm sized stearate@ZnO particles. For ZnO ∶ Cu = 2, the microstructure of the nanocomposites after catalytic activity testing is characterized by HAADF-STEM techniques. This reveals the construction of large Cu nanoparticles (2050 nm) decorated by small ZnO nanoparticles (35 nm). The catalytic activity of both composites for the synthesis of methanol from syn gas is evaluated.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000304102200033 Publication Date 2012-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 16 Open Access
Notes Fwo Approved Most recent IF: 4.123; 2012 IF: 3.829
Call Number UA @ lucian @ c:irua:98377 Serial 2702
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Author Piedigrosso, P.; Konya, Z.; Colomer, J.-F.; Fonseca, A.; Van Tendeloo, G.; Nagy, J.B.
Title Production of differently shaped multi-wall carbon nanotubes using various cobalt supported catalysts Type A1 Journal article
Year 2000 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 2 Issue 1 Pages 163-170
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Catalytic synthesis and transmission electron microscopy (TEM) of multi-wall carbon nanotubes are presented. Silica, zeolite and alumina supported cobalt catalysts were prepared by different methods (impregnation and ion-adsorption precipitation) and were used to produce nanotubes. The synthesis was carried out in a fixed bed flow reactor and the process was optimized in order to produce carbon nanotubes on a gram scale. The influence of various parameters such as the method of catalyst preparation, the nature of the support, cobalt concentration and reaction conditions on the formation of nanotubes was investigated. The carbon deposits were measured and the quality of nanotubes was determined by low and high resolution TEM. Multi-wall straight and coiled nanotubes were found to be fairly regular with an average inner (outer) diameter of 4-7 nm (8-23 nm) and with lengths up to 0.1 mm.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000084333800025 Publication Date 2002-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 53 Open Access
Notes Approved Most recent IF: 4.123; 2000 IF: 1.653
Call Number UA @ lucian @ c:irua:102889 Serial 2723
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Author Brito, B.G.A.; Hai, G.-Q.; Teixeira Rabelo, J.N.; Cândido, L.
Title A quantum Monte Carlo study on electron correlation in all-metal aromatic clusters MAl4 – (M = Li, Na, K, Rb, Cu, Ag and Au) Type A1 Journal article
Year 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 18 Pages 8639-8645
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using fixed-node diffusion quantum Monte Carlo (FN-DMC) simulation we investigate the electron correlation in all-metal aromatic clusters MAl4- (with M = Li, Na, K, Rb, Cu, Ag and Au). The electron detachment energies and electron affinities of the clusters are obtained. The vertical electron detachment energies obtained from the FN-DMC calculations are in very good agreement with the available experimental results. Calculations are also performed within the Hartree-Fock approximation, density-functional theory (DFT), and the couple-cluster (CCSD(T)) method. From the obtained results, we analyse the impact of the electron correlation effects in these bimetallic clusters and find that the correlation of the valence electrons contributes significantly to the detachment energies and electron affinities, varying between 20% and 50% of their total values. Furthermore, we discuss the electron correlation effects on the stability of the clusters as well as the accuracy of the DFT and CCSD(T) calculations in the present systems.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000334602900052 Publication Date 2014-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 10 Open Access
Notes ; This research was supported by CNPq, FAPESP and FAPEG (Brazil). ; Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:117247 Serial 2781
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