Nano Home

NANOlab Center of Excellence literature database

Home |  Show All |  Simple Search |  Advanced Search
Quick Search:
31–45 of 45 records found matching your query (RSS):
toggle visibility
Search within Results:
Display Options:
Select All    Deselect All << 1 2 >>
List View
 | 
Citations
 | 
Details
   print
  Records Links
Author Dixit, H.; Saniz, R.; Lamoen, D.; Partoens, B. pdf  doi
openurl 
  Title The quasiparticle band structure of zincblende and rocksalt ZnO Type A1 Journal article
  Year 2010 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat  
  Volume 22 Issue 12 Pages 125505,1-125505,7  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We present the quasiparticle band structure of ZnO in its zincblende (ZB) and rocksalt (RS) phases at the Γ point, calculated within the GW approximation. The effect of the pd hybridization on the quasiparticle corrections to the band gap is discussed. We compare three systems, ZB-ZnO which shows strong pd hybridization and has a direct band gap, RS-ZnO which is also hybridized but includes inversion symmetry and therefore has an indirect band gap, and ZB-ZnS which shows a weaker hybridization due to a change of the chemical species from oxygen to sulfur. The quasiparticle corrections are calculated with different numbers of valence electrons in the Zn pseudopotential. We find that the Zn20 + pseudopotential is essential for the adequate treatment of the exchange interaction in the self-energy. The calculated GW band gaps are 2.47 eV and 4.27 eV respectively, for the ZB and RS phases. The ZB-ZnO band gap is underestimated compared to the experimental value of 3.27 by ~ 0.8 eV. The RS-ZnO band gap compares well with the experimental value of 4.5 eV. The underestimation for ZB-ZnO is correlated with the strong pd hybridization. The GW band gap for ZnS is 3.57 eV, compared to the experimental value of 3.8 eV.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000275496600010 Publication Date 2010-03-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.649 Times cited 53 Open Access  
  Notes Iwt; Fwo; Bof-Nio Approved Most recent IF: 2.649; 2010 IF: 2.332  
  Call Number UA @ lucian @ c:irua:81531 Serial 2802  
Permanent link to this record
 
 
Author Miglio, A.; Saniz, R.; Waroquiers, D.; Stankovski, M.; Giantomassi, M.; Hautier, G.; Rignanese, G.-M.; Gonze, X. pdf  doi
openurl 
  Title Computed electronic and optical properties of SnO2 under compressive stress Type A1 Journal article
  Year 2014 Publication Optical materials Abbreviated Journal Opt Mater  
  Volume 38 Issue Pages 161-166  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We consider the effects of three different types of applied compressive stress on the structural, electronic and optical properties of rutile SnO2. We use standard density functional theory (OFT) to determine the structural parameters. The effective masses and the electronic band gap, as well as their stress derivatives, are computed within both DFT and many-body perturbation theory (MBPT). The stress derivatives for the SnO2 direct band gap are determined to be 62, 38 and 25 meV/GPa within MBPT for applied hydrostatic, biaxial and uniaxial stress, respectively. Compared to DFT, this is a clear improvement with respect to available experimental data. We also estimate the exciton binding energies and their stress coefficients and compute the absorption spectrum by solving the Bethe-Salpeter equation. (C) 2014 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000346228800028 Publication Date 2014-11-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-3467; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.238 Times cited 6 Open Access  
  Notes ; This work was supported by the FRS-FNRS through a FRIA grant (D.W.) and a FNRS grant (G.H.). This work was also supported by the IWT Project Number 080023 (ISIMADE), the Region Wallonne through WALL-ETSF project Number 816849, the EU-FP7 HT4TCOS Grant No. PCIG11-GA-2912-321988, the FRS-FNRS through contracts FRFC Number 2.4.589.09.F and AIXPHO (PDR Grant T-0238.13). The authors would like to thank Yann Pouillon and Jean-Michel Beuken for their valuable technical support and help with the test and build system of ABINIT. Computational resources have been provided by the supercomputing facilities of the Universite catholique de Louvain (CISM/UCL) and the Consortium des Equipements de Calcul Intensif en Federation Wallonie Bruxelles (CECI) funded by the Fonds de la Recherche Scientifique de Belgique (FRS-FNRS) under Grant No. 2.5020.11. ; Approved Most recent IF: 2.238; 2014 IF: 1.981  
  Call Number UA @ lucian @ c:irua:122747 Serial 460  
Permanent link to this record
 
 
Author Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. url  doi
openurl 
  Title Ab initio study of shallow acceptors in bixbyite V2O3 Type A1 Journal article
  Year 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 015703  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We present the results of our study on p-type dopability of bixbyite V2O3 using the Heyd, Scuseria, and Ernzerhof hybrid functional (HSE06) within the density functional theory (DFT) formalism. We study vanadium and oxygen vacancies as intrinsic defects and substitutional Mg, Sc, and Y as extrinsic defects. We find that Mg substituting V acts as a shallow acceptor, and that oxygen vacancies are electrically neutral. Hence, we predict Mg-doped V2O3 to be a p-type conductor. Our results also show that vanadium vacancies are relatively shallow, with a binding energy of 0.14 eV, so that they might also lead to p-type conductivity.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000347958600067 Publication Date 2015-01-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979;1089-7550; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.068 Times cited 3 Open Access  
  Notes FWO G015013; Hercules Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:122728 Serial 35  
Permanent link to this record
 
 
Author Bekaert, J.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles study of carbon impurities in CuInSe2 and CuGaSe2, present in non-vacuum synthesis methods Type A1 Journal article
  Year 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 015104  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract A first-principles study of the structural and electronic properties of carbon impurities in CuInSe2 and CuGaSe2 is presented. Carbon is present in organic molecules in the precursor solutions used in non-vacuum growth methods for CuInSe2 and CuGaSe2 based photovoltaic cells. These growth methods make more efficient use of material, time, and energy than traditional vacuum methods. The formation energies of several carbon impurities are calculated using the hybrid HSE06 functional. C Cu acts as a shallow donor, CIn and interstitial C yield deep donor levels in CuInSe2, while in CuGaSe2 CGa and interstitial C act as deep amphoteric defects. So, these defects reduce the majority carrier (hole) concentration in p-type CuInSe2 and CuGaSe2 by compensating the acceptor levels. The deep defects are likely to act as recombination centers for the photogenerated charge carriers and are thus detrimental for the performance of the photovoltaic cells. On the other hand, the formation energies of the carbon impurities are high, even under C-rich growth conditions. Thus, few C impurities will form in CuInSe2 and CuGaSe2 in thermodynamic equilibrium. However, the deposition of the precursor solution in non-vacuum growth methods presents conditions far from thermodynamic equilibrium. In this case, our calculations show that C impurities formed in non-equilibrium tend to segregate from CuInSe2 and CuGaSe2 by approaching thermodynamic equilibrium, e.g., via thorough annealing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000347958600055 Publication Date 2015-01-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979;1089-7550; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.068 Times cited 6 Open Access  
  Notes FWO G015013; Hercules Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:122064 Serial 1215  
Permanent link to this record
 
 
Author Amini, M.N.; Saniz, R.; Lamoen, D.; Partoens, B. doi  openurl
  Title Hydrogen impurities and native defects in CdO Type A1 Journal article
  Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 110 Issue 6 Pages 063521,1-063521,7  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We have used first-principles calculations based on density functional theory to study point defects in CdO within the local density approximation and beyond (LDA+U). Hydrogen interstitials and oxygen vacancies are found to act as shallow donors and can be interpreted as the cause of conductivity in CdO. Hydrogen can also occupy an oxygen vacancy in its substitutional form and also acts as a shallow donor. Similar to what was found for ZnO and MgO, hydrogen creates a multicenter bond with its six oxygen neighbors in CdO. The charge neutrality level for native defects and hydrogen impurities has been calculated. It is shown that in the case of native defects, it is not uniquely defined. Indeed, this level depends highly on the chemical potentials of the species and one can obtain different values for different end states in the experiment. Therefore, a comparison with experiment can only be made if the chemical potentials of the species in the experiment are well defined. However, for the hydrogen interstitial defect, since this level is independent of the chemical potential of hydrogen, one can obtain a unique value for the charge neutrality level. We find that the Fermi level stabilizes at 0.43 eV above the conduction band minimum in the case of the hydrogen interstitial defect, which is in good agreement with the experimentally reported value of 0.4 eV.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000295619300041 Publication Date 2011-09-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.068 Times cited 13 Open Access  
  Notes ; The authors gratefully acknowledge financial support from the IWT-Vlaanderen through the ISIMADE project, the FWO-Vlaanderen through Project G.0191.08 and the BOF-NOI of the University of Antwerp. This work was carried out using the HPC infrastructure at the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC. ; Approved Most recent IF: 2.068; 2011 IF: 2.168  
  Call Number UA @ lucian @ c:irua:93613 Serial 1533  
Permanent link to this record
 
 
Author Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles study of the optoelectronic properties and photovoltaic absorber layer efficiency of Cu-based chalcogenides Type A1 Journal article
  Year 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 120 Issue 120 Pages 085707  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Cu-based chalcogenides are promising materials for thin-film solar cells with more than 20% measured

cell efficiency. Using first-principles calculations based on density functional theory, the

optoelectronic properties of a group of Cu-based chalcogenides Cu2-II-IV-VI4 is studied. They are

then screened with the aim of identifying potential absorber materials for photovoltaic applications.

The spectroscopic limited maximum efficiency (SLME) introduced by Yu and Zunger [Phys. Rev.

Lett. 108, 068701 (2012)] is used as a metric for the screening. After constructing the currentvoltage

curve, the SLME is calculated from the maximum power output. The role of the nature of

the band gap, direct or indirect, and also of the absorptivity of the studied materials on the maximum

theoretical power conversion efficiency is studied. Our results show that Cu2II-GeSe4 with

II¼ Cd and Hg, and Cu2-II-SnS4 with II ¼ Cd, Hg, and Zn have a higher theoretical efficiency

compared with the materials currently used as absorber layer.		  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000383913400074 Publication Date 2016-08-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.068 Times cited 29 Open Access  
  Notes We acknowledge the financial support from the FWO-Vlaanderen through project G.0150.13N and a GOA fund from the University of Antwerp. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), bothfunded by the FWO-Vlaanderen and the Flemish Government–department EWI. Approved Most recent IF: 2.068  
  Call Number c:irua:135089 Serial 4113  
Permanent link to this record
 
 
Author Saniz, R.; Xu, Y.; Matsubara, M.; Amini, M.N.; Dixit, H.; Lamoen, D.; Partoens, B. pdf  doi
openurl 
  Title A simplified approach to the band gap correction of defect formation energies : Al, Ga, and In-doped ZnO Type A1 Journal article
  Year 2013 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids  
  Volume 74 Issue 1 Pages 45-50  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract The calculation of defect levels in semiconductors within a density functional theory approach suffers greatly from the band gap problem. We propose a band gap correction scheme that is based on the separation of energy differences in electron addition and relaxation energies. We show that it can predict defect levels with a reasonable accuracy, particularly in the case of defects with conduction band character, and yet is simple and computationally economical. We apply this method to ZnO doped with group III elements (Al, Ga, In). As expected from experiment, the results indicate that Zn substitutional doping is preferred over interstitial doping in Al, Ga, and In-doped ZnO, under both zinc-rich and oxygen-rich conditions. Further, all three dopants act as shallow donors, with the +1 charge state having the most advantageous formation energy. Also, doping effects on the electronic structure of ZnO are sufficiently mild so as to affect little the fundamental band gap and lowest conduction bands dispersion, which secures their n-type transparent conducting behavior. A comparison with the extrapolation method based on LDA+U calculations and with the HeydScuseriaErnzerhof hybrid functional (HSE) shows the reliability of the proposed scheme in predicting the thermodynamic transition levels in shallow donor systems.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000311062500009 Publication Date 2012-08-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3697; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.059 Times cited 36 Open Access  
  Notes Fwo; Bof-Nio Approved Most recent IF: 2.059; 2013 IF: 1.594  
  Call Number UA @ lucian @ c:irua:101782 Serial 3004  
Permanent link to this record
 
 
Author Saniz, R.; Sarmadian, N.; Partoens, B.; Batuk, M.; Hadermann, J.; Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles study of CO and OH adsorption on in-doped ZnO surfaces Type A1 Journal article
  Year 2019 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids  
  Volume 132 Issue Pages 172-181  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We present a first-principles computational study of CO and OH adsorption on non-polar ZnO (10¯10) surfaces doped with indium. The calculations were performed using a model ZnO slab. The position of the In dopants was varied from deep bulk-like layers to

the surface layers. It was established that the preferential location of the In atoms is at the surface by examining the dependence of

the defect formation energy as well as the surface energy on In location. The adsorption sites on the surface of ZnO and the energy

of adsorption of CO molecules and OH-species were determined in connection to In doping. It was found that OH has higher

bonding energy to the surface than CO. The presence of In atoms at the surface of ZnO is favorable for CO adsorption, resulting

in an elongation of the C-O bond and in charge transfer to the surface. The effect of CO and OH adsorption on the electronic

and conduction properties of surfaces was assessed. We conclude that In-doped ZnO surfaces should present a higher electronic

response upon adsorption of CO.		  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000472124700023 Publication Date 2019-04-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3697 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 2.059 Times cited 7 Open Access Not_Open_Access: Available from 26.04.2021  
  Notes FWO-Vlaanderen, G0D6515N ; ERA.Net RUS Plus, 096 ; VSC; HPC infrastructure of the University of Antwerp; FWO-Vlaanderen; Flemish Government-department EWI; Approved Most recent IF: 2.059  
  Call Number EMAT @ emat @UA @ admin @ c:irua:159656 Serial 5170  
Permanent link to this record
 
 
Author De Beule, C.; Saniz, R.; Partoens, B. pdf  doi
openurl 
  Title Crystalline topological states at a topological insulator junction Type A1 Journal article
  Year 2019 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids  
  Volume 128 Issue 128 Pages 144-151  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We consider an interface between two strong time-reversal invariant topological insulators having surface states with opposite spin chirality, or equivalently, opposite mirror Chern number. We show that such an interface supports gapless modes that are protected by mirror symmetry. The interface states are investigated with a continuum model for the Bi2Se3 class of topological insulators that takes into account terms up to third order in the crystal momentum, which ensures that the model has the correct symmetry. The model parameters are obtained from ab initio calculations. Finally, we consider the effect of rotational mismatch at the interface, which breaks the mirror symmetry and opens a gap in the interface spectrum.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000472693100013 Publication Date 2018-01-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3697 ISBN Additional Links UA library record; WoS full record  
  Impact Factor (down) 2.059 Times cited Open Access  
  Notes ; ; Approved Most recent IF: 2.059  
  Call Number UA @ admin @ c:irua:161391 Serial 5385  
Permanent link to this record
 
 
Author Saniz, R.; Bekaert, J.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles study of defects at Σ3 grain boundaries in CuGaSe2 Type A1 Journal article
  Year 2021 Publication Solid State Communications Abbreviated Journal Solid State Commun  
  Volume Issue Pages 114263  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)  
  Abstract We present a first-principles computational study of cation–Se 3 (112) grain boundaries in CuGaSe. We discuss the structure of these grain boundaries, as well as the effect of native defects and Na impurities on their electronic properties. The formation energies show that the defects will tend to form preferentially at the grain boundaries, rather than in the grain interiors. We find that in Ga-rich growth conditions Cu vacancies as well as Ga at Cu and Cu at Ga antisites are mainly responsible for having the equilibrium Fermi level pinned toward the middle of the gap, resulting in carrier depletion. The Na at Cu impurity in its +1 charge state contributes to this. In Ga-poor growth conditions, on the other hand, the formation energies of Cu vacancies and Ga at Cu antisites are comparatively too high for any significant influence on carrier density or on the equilibrium Fermi level position. Thus, under these conditions, the Cu at Ga antisites give rise to a -type grain boundary. Also, their formation energy is lower than the formation energy of Na at Cu impurities. Thus, the latter will fail to act as a hole barrier preventing recombination at the grain boundary, in contrast to what occurs in CuInSe grain boundaries. We also discuss the effect of the defects on the electronic properties of bulk CuGaSe, which we assume reflect the properties of the grain interiors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000652668500013 Publication Date 2021-03-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0038-1098 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) 1.554 Times cited 1 Open Access OpenAccess  
  Notes Fwo; We acknowledge the financial support of FWO-Vlaanderen, Belgium through project G.0150.13. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by FWO-Vlaanderen and the Flemish Government-department EWI. Approved Most recent IF: 1.554  
  Call Number EMAT @ emat @c:irua:176544 Serial 6703  
Permanent link to this record
 
 
Author Saniz, R.; Vercauteren, S.; Lamoen, D.; Partoens, B.; Barbiellini, B. pdf  doi
openurl 
  Title Accurate description of the van der Waals interaction of an electron-positron pair with the surface of a topological insulator Type P1 Proceeding
  Year 2014 Publication Journal of physics : conference series Abbreviated Journal  
  Volume 505 Issue Pages 012002  
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Positrons can be trapped in localized states at the surface of a material, and thus quite selectively interact with core or valence surface electrons. Hence, advanced surface positron spectroscopy techniques can present the ideal tools to study a topological insulator, where surface states play a fundamental role. We analyze the problem of a positron at a TI surface, assuming that it is a weakly physisorbed positronium (Ps) atom. To determine if the surface of interest in a material can sustain such a physisorption, an accurate description of the underlying van der Waals (vdW) interaction is essential. We have developed a first-principles parameterfree method, based on the density functional theory, to extract key parameters determining the vdW interaction potential between a Ps atom and the surface of a given material. The method has been successfully applied to quartz and preliminary results on Bi2Te2Se indicate the existence of a positron surface state. We discuss the robustness of our predictions versus the most relevant approximations involved in our approach.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000338216500002 Publication Date 2014-04-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1742-6588;1742-6596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) Times cited 2 Open Access  
  Notes ; We thank A. Weiss for very useful conversations. We acknowledge financial support from FWO-Vlaanderen (projectG.0150.13). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), adivision of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). B. B. is supported by DOE grants Nos. DE-FG02-07ER46352 and DE-AC02-05CH11231 for theory support at ALS, Berkeley, and a NERSC computer time allocation. ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:118264 Serial 46  
Permanent link to this record
 
 
Author Callewaert, V.; Saniz, R.; Barbiellini, B.; Partoens, B. url  doi
openurl 
  Title Surface states and positron annihilation spectroscopy: results and prospects from a first-principles approach Type A1 Journal article
  Year 2017 Publication Journal of physics : conference series Abbreviated Journal  
  Volume 791 Issue 791 Pages 012036  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The trapping of positrons at the surface of a material can be exploited to study quite selectively the surface properties of the latter by means of positron annihilation spectroscopy techniques. To support these, it is desirable to be able to theoretically predict the existence of such positronic surface states and to describe their annihilation characteristics with core or valence surface electrons in a reliable way. Here, we build on the well-developed first-principles techniques for the study of positrons in bulk solids as well as on previous models for surfaces, and investigate two schemes that can improve the theoretical description of the interaction of positrons with surfaces. One is based on supplementing the local-density correlation potential with the corrugated image potential at the surface, and the other is based on the weighted-density approximation to correlation. We discuss our results for topological insulators, graphene layers, and quantum dots, with emphasis on the information that can be directly related to experiment. We also discuss some open theoretical problems that should be addressed by future research.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000400610500036 Publication Date 2017-02-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1742-6588 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) Times cited 1 Open Access  
  Notes We acknowledge financial support from FWO-Vlaanderen (projects G.0150.13 and G.0224.14N). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University’s Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02- 05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. Approved Most recent IF: NA  
  Call Number CMT @ cmt @ c:irua:140847 Serial 4425  
Permanent link to this record
 
 
Author Eijt, S.W.H.; Shi, W.; Mannheim, A.; Butterling, M.; Schut, H.; Egger, W.; Dickmann, M.; Hugenschmidt, C.; Shakeri, B.; Meulenberg, R.W.; Callewaert, V.; Saniz, R.; Partoens, B.; Barbiellini, B.; Bansil, A.; Melskens, J.; Zeman, M.; Smets, A.H.M.; Kulbak, M.; Hodes, G.; Cahen, D.; Brück, E. url  doi
openurl 
  Title New insights into the nanostructure of innovative thin film solar cells gained by positron annihilation spectroscopy Type A1 Journal article
  Year 2017 Publication Journal of physics : conference series Abbreviated Journal  
  Volume 791 Issue 791 Pages 012021  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Recent studies showed that positron annihilation methods can provide key insights into the nanostructure and electronic structure of thin film solar cells. In this study, positron annihilation lifetime spectroscopy (PALS) is applied to investigate CdSe quantum dot (QD) light absorbing layers, providing evidence of positron trapping at the surfaces of the QDs. This enables one to monitor their surface composition and electronic structure. Further, 2D-Angular Correlation of Annihilation Radiation (2D-ACAR) is used to investigate the nanostructure of divacancies in photovoltaic-high-quality a-Si:H films. The collected momentum distributions were converted by Fourier transformation to the direct space representation of the electron-positron autocorrelation function. The evolution of the size of the divacancies as a function of hydrogen dilution during deposition of a-Si:H thin films was examined. Finally, we present a first positron Doppler Broadening of Annihilation Radiation (DBAR) study of the emerging class of highly efficient thin film solar cells based on perovskites.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000400610500021 Publication Date 2017-02-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1742-6588 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) Times cited 1 Open Access  
  Notes The work at Delft University of Technology was supported by the China Scholarship Council (CSC) grant of W.S., by ADEM, A green Deal in Energy Materials of the Ministry of Economic Affairs of The Netherlands (www.adem- innovationlab.nl), and the STW Vidi grant of A.S., Grant No. 10782. The PALS study is based upon experiments performed at the PLEPS instrument of the NEPOMUC facility at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and was supported by the European Commission under the 7 th Framework Programme, Key Action: Strengthening the European Research Area, Research Infrastructures, Contract No. 226507, NMI3. The work at University of Maine was supported by the National Science Foundation under Grant No. DMR-1206940. Research at the University of Antwerp was supported by FWO grants G022414N and G015013. The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University's Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02-05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. The work at the Weizmann Institute was supported by the Sidney E. Frank Foundation through the Israel Science Foundation, by the Israel Ministry of Science, and the Israel National Nano-Initiative. D.C. holds the Sylvia and Rowland Schaefer Chair in Energy Research. Approved Most recent IF: NA  
  Call Number CMT @ cmt @ c:irua:140850 Serial 4426  
Permanent link to this record
 
 
Author Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Batuk, M.; Hadermann, J.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. url  doi
openurl 
  Title Effect of zinc oxide modification by indium oxide on microstructure, adsorbed surface species, and sensitivity to CO Type A1 Journal article
  Year 2019 Publication Frontiers in materials Abbreviated Journal  
  Volume 6 Issue 6 Pages  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Additives in semiconductor metal oxides are commonly used to improve sensing behavior of gas sensors. Due to complicated effects of additives on the materials microstructure, adsorption sites and reactivity to target gases the sensing mechanism with modified metal oxides is a matter of thorough research. Herein, we establish the promoting effect of nanocrystalline zinc oxide modification by 1-7 at.% of indium on the sensitivity to CO gas due to improved nanostructure dispersion and concentration of active sites. The sensing materials were synthesized via an aqueous coprecipitation route. Materials composition, particle size and BET area were evaluated using X-ray diffraction, nitrogen adsorption isotherms, high-resolution electron microscopy techniques and EDX-mapping. Surface species of chemisorbed oxygen, OH-groups, and acid sites were characterized by probe molecule techniques and infrared spectroscopy. It was found that particle size of zinc oxide decreased and the BET area increased with the amount of indium oxide. The additive was observed as amorphous indium oxide segregated on agglomerated ZnO nanocrystals. The measured concentration of surface species was higher on In2O3-modified zinc oxide. With the increase of indium oxide content, the sensor response of ZnO/In2O3 to CO was improved. Using in situ infrared spectroscopy, it was shown that oxidation of CO molecules was enhanced on the modified zinc oxide surface. The effect of modifier was attributed to promotion of surface OH-groups and enhancement of CO oxidation on the segregated indium ions, as suggested by DFT in previous work.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000461540600001 Publication Date 2019-03-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2296-8016 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) Times cited 11 Open Access OpenAccess  
  Notes ; Research was supported by the grant from Russian Science Foundation (project No. 18-73-00071). ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:158540 Serial 5205  
Permanent link to this record
 
 
Author Barbiellini, B.; Kuriplach, J.; Saniz, R. url  doi
openurl 
  Title Study of rechargeable batteries using advanced spectroscopic and computational techniques Type Editorial
  Year 2021 Publication Condensed Matter Abbreviated Journal  
  Volume 6 Issue 3 Pages 26  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract Improving the efficiency and longevity of energy storage systems based on Li- and Na-ion rechargeable batteries presents a major challenge. The main problems are essentially capacity loss and limited cyclability. These effects are due to a hierarchy of factors spanning various length and time scales, interconnected in a complex manner. As a consequence, and in spite of several decades of research, a proper understanding of the ageing process has remained somewhat elusive. In recent years, however, combinations of advanced spectroscopy techniques and first-principles simulations have been applied with success to tackle this problem. In this Special Issue, we are pleased to present a selection of articles that, by precisely applying these methods, unravel key aspects of the reduction-oxidation reaction and intercalation processes. Furthermore, the approaches presented provide improvements to standard diagnostic and characterisation techniques, enabling the detection of possible Li-ion flow bottlenecks causing the degradation of capacity and cyclability.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000699368400001 Publication Date 2021-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2410-3896 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor (down) Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181630 Serial 6890  
Permanent link to this record
Select All    Deselect All << 1 2 >>
List View
 | 
Citations
 | 
Details
   print
toggle visibility
Save Citations:
Export Records:
Home CQL Search  |  Library Search  |  Show Record  |  Extract Citations Help