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Author Deng, S.; Verbruggen, S.W.; Lenaerts, S.; Martens, J.A.; Van den Berghe, S.; Devloo-Casier, K.; Devulder, W.; Dendoover, J.; Deduytsche, D.; Detavernier, C.
Title Controllable nitrogen doping in as deposited TiO2 film and its effect on post deposition annealing Type A1 Journal article
Year 2014 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A
Volume 32 Issue 1 Pages 01a123
Keywords (up) A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In order to narrow the band gap of TiO2, nitrogen doping by combining thermal atomic layer deposition (TALD) of TiO2 and plasma enhanced atomic layer deposition (PEALD) of TiN has been implemented. By altering the ratio between TALD TiO2 and PEALD TiN, the as synthesized TiOxNy films showed different band gaps (from 1.91 eV to 3.14 eV). In situ x-ray diffraction characterization showed that the crystallization behavior of these films changed after nitrogen doping. After annealing in helium, nitrogen doped TiO2 films crystallized into rutile phase while for the samples annealed in air a preferential growth of the anatase TiO2 along (001) orientation was observed. Photocatalytic tests of the degradation of stearic acid were done to evaluate the effect of N doping on the photocatalytic activity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000335847600023 Publication Date 2013-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0734-2101 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.374 Times cited 10 Open Access
Notes ; The authors wish to thank the Research Foundation-Flanders (FWO) for financial support. The authors acknowledge the European Research Council for funding under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement Nos. 239865-COCOON and 246791-COUNTATO. The authors also acknowledge the support from UGENT-GOA-01G01513 and IWT-SBO SOSLion. J.A.M. acknowledges the Flemish government for long-term structural funding (Methusalem). J.D. acknowledges the Flemisch FWO for a postdoctoral fellowship. ; Approved Most recent IF: 1.374; 2014 IF: 2.322
Call Number UA @ admin @ c:irua:117296 Serial 5936
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Author Clima, S.; Garbin, D.; Opsomer, K.; Avasarala, N.S.; Devulder, W.; Shlyakhov, I.; Keukelier, J.; Donadio, G.L.; Witters, T.; Kundu, S.; Govoreanu, B.; Goux, L.; Detavernier, C.; Afanas'ev, V.; Kar, G.S.; Pourtois, G.
Title Ovonic threshold-switching GexSey chalcogenide materials : stoichiometry, trap nature, and material relaxation from first principles Type A1 Journal article
Year 2020 Publication Physica Status Solidi-Rapid Research Letters Abbreviated Journal Phys Status Solidi-R
Volume Issue Pages 1900672
Keywords (up) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Density functional theory simulations are used to identify the structural factors that define the material properties of ovonic threshold switches (OTS). They show that the nature of mobility-gap trap states in amorphous Ge-rich Ge50Se50 is related to Ge-Ge bonds, whereas in Se-rich Ge30Se70 the Ge valence-alternating-pairs and Se lone-pairs dominate. To obtain a faithful description of the electronic structure and delocalization of states, it is required to combine hybrid exchange-correlation functionals with large unit-cell models. The extent of localization of electronic states depends on the applied external electric field. Hence, OTS materials undergo structural changes during electrical cycling of the device, with a decrease in the population of less exothermic Ge-Ge bonds in favor of more exothermic Ge-Se. This reduces the amount of charge traps, which translates into coordination changes, an increase in mobility-gap, and subsequently changes in the selector-device electrical parameters. The threshold voltage drift process can be explained by natural evolution of the nonpreferred Ge-Ge bonds (or “chains”/clusters thereof) in Ge-rich GexSe1-x. The effect of extrinsic doping is shown for Si and N, which introduce strong covalent bonds into the system, increase both mobility-gap and crystallization temperature, and decrease the leakage current.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000512431100001 Publication Date 2020-01-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-6254 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.8 Times cited 3 Open Access
Notes ; This work was carried out in the framework of the imec Core CMOS-Emerging Memory Program. Financial support from EU H2020-NMBPTO-IND-2018 project “INTERSECT” (Grant No. 814487) is acknowledged. ; Approved Most recent IF: 2.8; 2020 IF: 3.032
Call Number UA @ admin @ c:irua:166492 Serial 6575
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Author Minjauw, M.M.; Solano, E.; Sree, S.P.; Asapu, R.; Van Daele, M.; Ramachandran, R.K.; Heremans, G.; Verbruggen, S.W.; Lenaerts, S.; Martens, J.A.; Detavernier, C.; Dendooven, J.
Title Plasma-enhanced atomic layer deposition of silver using Ag(fod)(PEt3) and NH3-plasma Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 17 Pages 7114-7121
Keywords (up) A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract A plasma-enhanced atomic layer deposition (ALD) process using the Ag(fod)(PEt3) precursor [(triethylphosphine)(6,6,7,7,8,8,8-heptafluoro-2,2-dimethy1-3,5-octanedionate)silver(I)] in combination with NH3-plasma is reported. The steady growth rate of the reported process (0.24 +/- 0.03 nm/cycle) was found to be 6 times larger than that of the previously reported Ag ALD process based on the same precursor in combination with H-2-plasma (0.04 +/- 0.02 nm/cycle). The ALD characteristics of the H-2-plasma and NH3-plasma processes were verified. The deposited Ag films were polycrystalline face-centered cubic Ag for both processes. The film morphology was investigated by ex situ scanning electron microscopy and grazing-incidence small-angle X-ray scattering, and it was found that films grown with the NH3-plasma process exhibit a much higher particle areal density and smaller particle sizes on oxide substrates compared to those deposited using the H-2-plasma process. This control over morphology of the deposited Ag is important for applications in catalysis and plasmonics. While films grown with the H-2-plasma process had oxygen impurities (similar to 9 atom %) in the bulk, the main impurity for the NH3-plasma process was nitrogen (similar to 7 atom %). In situ Fourier transform infrared spectroscopy experiments suggest that these nitrogen impurities are derived from NH surface groups generated during the NH3-plasma, which interact with the precursor molecules during the precursor pulse. We propose that the reaction of these surface groups with the precursor leads to additional deposition of Ag atoms during the precursor pulse compared to the H-2-plasma process, which explains the enhanced growth rate of the NH3-plasma process.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000410868600012 Publication Date 2017-08-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 9 Open Access
Notes ; M.M.M. and J.D. acknowledge the Fonds Wetenschappelijk Onderzoek Vlaanderen (FWO Vlaanderen) for financial support through a personal research grant. We also acknowledge FWO Vlaanderen for providing project funding for this work. We are grateful to the ESRF staff for smoothly running the synchrotron and beamline facilities. We also thank Olivier Janssens for performing the SEM measurements and Stefaan Broekaert for mechanical assistance. J.A.M. acknowledges the Flemish Government for long-term structural funding (Methusalem). ; Approved Most recent IF: 9.466
Call Number UA @ admin @ c:irua:146757 Serial 5983
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Author Zankowski, S.P.; Van Hoecke, L.; Mattelaer, F.; de Raedt, M.; Richard, O.; Detavernier, C.; Vereecken, P.M.
Title Redox layer deposition of thin films of MnO2 on nanostructured substrates from aqueous solutions Type A1 Journal article
Year 2019 Publication Chemistry of materials Abbreviated Journal
Volume 31 Issue 13 Pages 4805-4816
Keywords (up) A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this work, we report a new method for depositing thin films of MnO2 on planar and complex nanostructured surfaces, with high precision and conformality. The method is based on repeating cycles of adsorption of an unsaturated alcohol on a surface, followed by its oxidation with aqueous KMnO4 and formation of thin, solid MnO2. The amount of manganese oxide formed in each cycle is limited by the quantity of the adsorbed alcohol; thus, the growth exhibits the self-limiting characteristics of atomic layer deposition (ALD). Contrary to the typical ALD, however, the new redox layer deposition is performed in air, at room temperature, using common chemicals and simple laboratory glassware, which greatly reduces its cost and complexity. We also demonstrate application of the method for the fabrication of a nanostructured MnO2/Ni electrode, which was not possible with thermal ALD because of the rapid decomposition of the gaseous precursor on the high surface-area substrate. Thanks to its simplicity, the conformal deposition of MnO2 can be easily upscaled and thus exploited for its numerous (electro)chemical applications.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000475408400021 Publication Date 2019-06-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756; 1520-5002 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:161225 Serial 8465
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