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Author Schoeters, B.; Leenaerts, O.; Pourtois, G.; Partoens, B.
Title Ab-initio study of the segregation and electronic properties of neutral and charged B and P dopants in Si and Si/SiO2 nanowires Type A1 Journal article
Year 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 118 Issue 118 Pages 104306
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We perform first-principles calculations to investigate the preferred positions of B and P dopants, both neutral and in their preferred charge state, in Si and Si/SiO2 core-shell nanowires (NWs). In order to understand the observed trends in the formation energy, we isolate the different effects that determine these formation energies. By making the distinction between the unrelaxed and the relaxed formation energy, we separate the impact of the relaxation from that of the chemical environment. The unrelaxed formation energies are determined by three effects: (i) the effect of strain caused by size mismatch between the dopant and the host atoms, (ii) the local position of the band edges, and (iii) a screening effect. In the case of the SiNW (Si/SiO2 NW), these effects result in an increase of the formation energy away from the center (interface). The effect of relaxation depends on the relative size mismatch between the dopant and host atoms. A large size mismatch causes substantial relaxation that reduces the formation energy considerably, with the relaxation being more pronounced towards the edge of the wires. These effects explain the surface segregation of the B dopants in a SiNW, since the atomic relaxation induces a continuous drop of the formation energy towards the edge. However, for the P dopants, the formation energy starts to rise when moving from the center but drops to a minimum just next to the surface, indicating a different type of behavior. It also explains that the preferential location for B dopants in Si/SiO2 core-shell NWs is inside the oxide shell just next to the interface, whereas the P dopants prefer the positions next to the interface inside the Si core, which is in agreement with recent experiments. These preferred locations have an important impact on the electronic properties of these core-shell NWs. Our simulations indicate the possibility of hole gas formation when B segregates into the oxide shell.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000361636900031 Publication Date 2015-09-09
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 3 Open Access
Notes This work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish government and the Universiteit Antwerpen. Approved Most recent IF: 2.068; 2015 IF: 2.183
Call Number c:irua:128729 Serial 4056
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Author Leenaerts, O.; Partoens, B.; Peeters, F.M.
Title Adsorption of small molecules on graphene Type A1 Journal article
Year 2009 Publication Microelectronics journal Abbreviated Journal Microelectron J
Volume 40 Issue 4/5 Pages 860-862
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the adsorption process of small molecules on graphene through first-principles calculations and show the presence of two main charge transfer mechanisms. Which mechanism is the dominant one depends on the magnetic properties of the adsorbing molecules. We explain these mechanisms through the density of states of the system and the molecular orbitals of the adsorbates, and demonstrate the possible difficulties in calculating the charge transfer from first principles between a graphene sheet and a molecule. Our results are in good agreement with experiment.
Address
Corporate Author Thesis
Publisher Place of Publication Luton Editor
Language Wos 000265870200058 Publication Date 2008-12-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-2692; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) 1.163 Times cited 116 Open Access
Notes Approved Most recent IF: 1.163; 2009 IF: 0.778
Call Number UA @ lucian @ c:irua:77030 Serial 65
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Author Leenaerts, O.; Partoens, B.; Peeters, F.M.; Volodin, A.; van Haesendonck, C.
Title The work function of few-layer graphene Type A1 Journal article
Year 2017 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 29 Issue 3 Pages 035003
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A theoretical and experimental study of the work function of few-layer graphene is reported. The influence of the number of layers on the work function is investigated in the presence of a substrate, a molecular dipole layer, and combinations of the two. The work function of few-layer graphene is almost independent of the number of layers with only a difference between monolayer and multilayer graphene of about 60 meV. In the presence of a charge-donating substrate the charge distribution is found to decay exponentially away from the substrate and this is directly reflected in the work function of few-layer graphene. A dipole layer changes the work function only when placed in between the substrate and few-layer graphene through a change of the charge transfer between the two.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000425250600002 Publication Date 2016-11-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor (down) Times cited 61 Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:164938 Serial 8760
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