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| Author | Saniz, R.; Bekaert, J.; Partoens, B.; Lamoen, D. | ||||
| 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. | ||||
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| 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 | 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 | Nematollahi, P.; Barbiellini, B.; Bansil, A.; Lamoen, D.; Qingying, J.; Mukerjee, S.; Neyts, E.C. | ||||
| Title | Identification of a Robust and Durable FeN4CxCatalyst for ORR in PEM Fuel Cells and the Role of the Fifth Ligand | Type | A1 Journal article | ||
| Year | 2022 | Publication | ACS catalysis | Abbreviated Journal | Acs Catal |
| Volume |
Issue | Pages | 7541-7549 | ||
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | Although recent studies have advanced the understanding of pyrolyzed Fe−N−C materials as oxygen reduction reaction (ORR) catalysts, the atomic and electronic structures of the active sites and their detailed reaction mechanisms still remain unknown. Here, based on first-principles density functional theory (DFT) computations, we discuss the electronic structures of three FeN4 catalytic centers with different local topologies of the surrounding C atoms with a focus on unraveling the mechanism of their ORR activity in acidic electrolytes. Our study brings back a forgotten, synthesized pyridinic Fe−N coordinate to the community’s attention, demonstrating that this catalyst can exhibit excellent activity for promoting direct four-electron ORR through the addition of a fifth ligand such as −NH2, −OH, and −SO4. We also identify sites with good stability properties through the combined use of our DFT calculations and Mössbauer spectroscopy data. |
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000823193100001 | Publication Date | 2022-06-10 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2155-5435 | ISBN | Additional Links | UA library record; WoS full record; WoS full record; WoS citing articles | |
| Impact Factor | 12.9 | Times cited | Open Access | OpenAccess | |
| Notes | Basic Energy Sciences, DE-FG02-07ER46352 ; Fonds Wetenschappelijk Onderzoek, 1261721N ; Opetus- ja Kulttuuriministeri?; Department of Energy, DE-EE0008416 ; | Approved | Most recent IF: 12.9 | ||
| Call Number | EMAT @ emat @c:irua:189000 | Serial | 7073 | ||
| Permanent link to this record | |||||
| Author | Bercx, M.; Mayda, S.; Depla, D.; Partoens, B.; Lamoen, D. | ||||
| Title | Plasmonic effects in the neutralization of slow ions at a metallic surface | Type | A1 Journal Article | ||
| Year | 2023 | Publication | Contributions to Plasma Physics | Abbreviated Journal | Contrib. Plasma Phys |
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Issue | Pages | |||
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | Secondary electron emission is an important process that plays a significant role in several plasma‐related applications. As measuring the secondary electron yield experimentally is very challenging, quantitative modelling of this process to obtain reliable yield data is critical as input for higher‐scale simulations. Here, we build upon our previous work combining density functional theory calculations with a model originally developed by Hagstrum to extend its application to metallic surfaces. As plasmonic effects play a much more important role in the secondary electron emission mechanism for metals, we introduce an approach based on Poisson point processes to include both surface and bulk plasmon excitations to the process. The resulting model is able to reproduce the yield spectra of several available experimental results quite well but requires the introduction of global fitting parameters, which describe the strength of the plasmon interactions. Finally, we use an in‐house developed workflow to calculate the electron yield for a list of elemental surfaces spanning the periodic table to produce an extensive data set for the community and compare our results with more simplified approaches from the literature. | ||||
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| Language | Wos | 001067651300001 | Publication Date | 2023-09-16 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0863-1042 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | 1.6 | Times cited | Open Access | Not_Open_Access | |
| Notes | We acknowledge the financial support of FWO-Vlaanderen through project G.0216.14N. 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 the FWO-Vlaanderen and the Flemish Government-department EWI. | Approved | Most recent IF: 1.6; 2023 IF: 1.44 | ||
| Call Number | EMAT @ emat @c:irua:200330 | Serial | 8962 | ||
| Permanent link to this record | |||||