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Author |
Sirotina, A.P.; Callaert, C.; Volykhov, A.A.; Frolov, A.S.; Sanchez-Barriga, J.; Knop-Gericke, A.; Hadermann, J.; Yashina, L.V. |
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Title |
Mechanistic studies of gas reactions with multicomponent solids : what can we learn by combining NAP XPS and atomic resolution STEM/EDX? |
Type |
A1 Journal article |
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Year  |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
123 |
Issue |
43 |
Pages |
26201-26210 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Rapid development of experimental techniques has enabled real time studies of solid gas reactions at the level reaching the atomic scale. In the present paper, we focus on a combination of atomic resolution STEM/EDX, which visualizes the reaction zone, and near ambient pressure (NAP) XPS, which collects information for a surface layer of variable thickness under reaction conditions. We compare the behavior of two affined topological insulators, Bi2Te3 and Sb2Te3. We used a simple reaction with molecular oxygen occurring at 298 K, which is of practical importance to avoid material degradation. Despite certain limitations, a combination of in situ XPS and ex situ cross-sectional STEM/EDX allowed us to obtain a self-consistent picture of the solid gas reaction mechanism for oxidation of Sb2Te3 and Bi2Te3 crystals, which includes component redistribution between the oxide and the subsurface layer and Te segregation with formation of a thin ordered layer at the interface. The process is multistep in case of both compounds. At the very beginning of the oxidation process the reactivity is determined by the energy benefit of the corresponding element oxygen bond formation. Further in the oxidation process, the behavior of these two compounds becomes similar and features component redistribution between the oxide and the subsurface layer. |
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Wos |
000493865700019 |
Publication Date |
2019-10-03 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:164664 |
Serial |
6310 |
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Author |
Eren, I.; Ozen, S.; Sozen, Y.; Yagmurcukardes, M.; Sahin, H. |
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Title |
Vertical van der Waals heterostructure of single layer InSe and SiGe |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
123 |
Issue |
51 |
Pages |
31232-31237 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
We present a first-principles investigation on the stability, electronic structure, and mechanical response of ultrathin heterostructures composed of single layers of InSe and SiGe. First, by performing total energy optimization and phonon calculations, we show that single layers of InSe and SiGe can form dynamically stable heterostructures in 12 different stacking types. Valence and conduction band edges of the heterobilayers form a type-I heterojunction having a tiny band gap ranging between 0.09 and 0.48 eV. Calculations on elastic-stiffness tensor reveal that two mechanically soft single layers form a heterostructure which is stiffer than the constituent layers because of relatively strong interlayer interaction. Moreover, phonon analysis shows that the bilayer heterostructure has highly Raman active modes at 205.3 and 43.7 cm(-1), stemming from the out-of-plane interlayer mode and layer breathing mode, respectively. Our results show that, as a stable type-I heterojunction, ultrathin heterobilayer of InSe/SiGe holds promise for nanoscale device applications. |
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Wos |
000505632900050 |
Publication Date |
2019-12-03 |
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Abbreviated Series Title |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:165718 |
Serial |
6332 |
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Author |
Saniz, R.; Sarmadian, N.; Partoens, B.; Batuk, M.; Hadermann, J.; Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Lamoen, D. |
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Title |
First-principles study of CO and OH adsorption on in-doped ZnO surfaces |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
The journal of physics and chemistry of solids |
Abbreviated Journal |
J Phys Chem Solids |
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Volume |
132 |
Issue |
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Pages |
172-181 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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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. |
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Wos |
000472124700023 |
Publication Date |
2019-04-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-3697 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.059 |
Times cited |
7 |
Open Access |
Not_Open_Access: Available from 26.04.2021
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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 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:159656 |
Serial |
5170 |
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Author |
De Beule, C.; Saniz, R.; Partoens, B. |
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Title |
Crystalline topological states at a topological insulator junction |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
The journal of physics and chemistry of solids |
Abbreviated Journal |
J Phys Chem Solids |
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Volume |
128 |
Issue |
128 |
Pages |
144-151 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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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. |
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Place of Publication |
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Wos |
000472693100013 |
Publication Date |
2018-01-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-3697 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
2.059 |
Times cited |
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Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.059 |
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Call Number |
UA @ admin @ c:irua:161391 |
Serial |
5385 |
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Author |
Hofman, J.; Castanheiro, A.; Nuyts, G.; Joosen, S.; Spassov, S.; Blust, R.; De Wael, K.; Lenaerts, S.; Samson, R. |
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Title |
Impact of urban street canyon architecture on local atmospheric pollutant levels and magneto-chemical PM10 composition : an experimental study in Antwerp, Belgium |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
The science of the total environment |
Abbreviated Journal |
Sci Total Environ |
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Volume |
712 |
Issue |
712 |
Pages |
135534 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
As real-life experimental data on natural ventilation of atmospheric pollution levels in urban street canyons is still scarce and has proven to be complex, this study, experimentally evaluated the impact of an urban street canyon opening on local atmospheric pollution levels, during a 2-week field campaign in a typical urban street canyon in Antwerp, Belgium. Besides following up on atmospheric particulate matter (PM), ultrafine particles (UFPs) and black carbon (BC) levels, the magneto-chemical PM10 composition was quantified to identify contributions of specific elements in enclosed versus open street canyon sections. Results indicated no higher overall PM, UFP and BC concentrations at the enclosed site compared to the open site, but significant day-to-day variability between both monitoring locations, depending on the experienced wind conditions. On days with oblique wind regimes (4 out of 14), natural ventilation was observed at the open location while higher element contributions of Ca, Fe, Co, Ni, Cu, Zn and Sr were exhibited at the enclosed location. Magnetic properties correlated with the PM10 filter loading, and elemental content of Fe, Cr, Mn and Ti. Magnetic bivariate ratios identified finel-grained magnetite carriers with grain sizes below 0.1 μm, indicating similar magnetic source contributions at both monitoring locations. Our holistic approach, combining atmospheric monitoring with magneto-chemical PM characterization has shown the complex impact of real-life wind flow regimes, different source contributions and local traffic dynamics on the resulting pollutant concentrations and contribute to a better understanding on the urban ventilation processes of atmospheric pollution. |
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Wos |
000512369600078 |
Publication Date |
2019-11-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0048-9697 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.9 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.9 |
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Call Number |
UA @ admin @ c:irua:165459 |
Serial |
5654 |
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Author |
Shi, P.; Liu, M.; Ratkowsky, D.A.; Gielis, J.; Su, J.; Yu, X.; Wang, P.; Zhang, L.; Lin, Z.; Schrader, J. |
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Title |
Leaf area-length allometry and its implications in leaf shape evolution |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Trees: structure and function |
Abbreviated Journal |
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Volume |
33 |
Issue |
4 |
Pages |
1073-1085 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
According to Thompson’s principle of similarity, the area of an object should be proportional to its length squared. However, leaf area–length data of some plants have been demonstrated not to follow the principle of similarity. We explore the reasons why the leaf area–length allometry deviates from the principle of similarity and examine whether there is a general model describing the relationship among leaf area, width and length. We sampled more than 11,800 leaves from six classes of woody and herbaceous plants and tested the leaf area–length allometry. We compared six mathematical models based on root-mean-square error as the measure of goodness-of-fit. The best supported model described a proportional relationship between leaf area and the product of leaf width and length (i.e., the Montgomery model). We found that the extent to which the leaf area–length allometry deviates from the principle of similarity depends upon the extent of variation of the ratio of leaf width to length. Estimates of the parameter of the Montgomery model ranged between 1/2, which corresponds to a triangular leaf with leaf length as its height and leaf width as its base, and π/4, which corresponds to an elliptical leaf with leaf length as its major axis and leaf width as its minor axis, for the six classes of plants. The narrow range in practice of the Montgomery parameter implies an evolutionary stability for the leaf area of large-leaved plants despite the fact that leaf shapes of these plants are rather different. |
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Wos |
000475992600010 |
Publication Date |
2019-04-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0931-1890; 1432-2285 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:159970 |
Serial |
8170 |
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Author |
van den Bos, K.H.W.; Janssens, L.; De Backer, A.; Nellist, P.D.; Van Aert, S. |
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Title |
The atomic lensing model: new opportunities for atom-by-atom metrology of heterogeneous nanomaterials |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
203 |
Issue |
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Pages |
155 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The atomic lensing model has been proposed as a promising method facilitating atom-counting in heterogeneous nanocrystals [1]. Here, image simulations will validate the model, which describes dynamical diffraction as a superposition of individual atoms focussing the incident electrons. It will be demonstrated that the model is reliable in the annular dark field regime for crystals having columns containing dozens of atoms. By using the principles of statistical detection theory, it will be shown that this model gives new opportunities for detecting compositional differences. |
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Corporate Author |
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Place of Publication |
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Wos |
000465021000020 |
Publication Date |
2018-12-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
4 |
Open Access |
OpenAccess |
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Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0369.15N, G.0502.18N and WO.010.16N), and by personal grants to K.H.W. van den Bos and A. De Backer. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:155721 |
Serial |
5074 |
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Author |
Fatermans, J.; Van Aert, S.; den Dekker, A.J. |
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Title |
The maximum a posteriori probability rule for atom column detection from HAADF STEM images |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
201 |
Issue |
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Pages |
81-91 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Recently, the maximum a posteriori (MAP) probability rule has been proposed as an objective and quantitative method to detect atom columns and even single atoms from high-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images. The method combines statistical parameter estimation and model-order selection using a Bayesian framework and has been shown to be especially useful for the analysis of the structure of beam-sensitive nanomaterials. In order to avoid beam damage, images of such materials are usually acquired using a limited incoming electron dose resulting in a low contrast-to-noise ratio (CNR) which makes visual inspection unreliable. This creates a need for an objective and quantitative approach. The present paper describes the methodology of the MAP probability rule, gives its step-by-step derivation and discusses its algorithmic implementation for atom column detection. In addition, simulation results are presented showing that the performance of the MAP probability rule to detect the correct number of atomic columns from HAADF STEM images is superior to that of other model-order selection criteria, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Moreover, the MAP probability rule is used as a tool to evaluate the relation between STEM image quality measures and atom detectability resulting in the introduction of the so-called integrated CNR (ICNR) as a new image quality measure that better correlates with atom detectability than conventional measures such as signal-to-noise ratio (SNR) and CNR. |
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Wos |
000466343800009 |
Publication Date |
2019-02-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
OpenAccess |
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Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N). This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant Agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:157176 |
Serial |
5153 |
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Author |
Müller-Caspary, K.; Krause, F.F.; Winkler, F.; Béché, A.; Verbeeck, J.; Van Aert, S.; Rosenauer, A. |
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Title |
Comparison of first moment STEM with conventional differential phase contrast and the dependence on electron dose |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
203 |
Issue |
203 |
Pages |
95-104 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
This study addresses the comparison of scanning transmission electron microscopy (STEM) measurements of momentum transfers using the first moment approach and the established method that uses segmented annular detectors. Using an ultrafast pixelated detector to acquire four-dimensional, momentum-resolved STEM signals, both the first moment calculation and the calculation of the differential phase contrast (DPC) signals are done for the same experimental data. In particular, we investigate the ability to correct the segment-based signal to yield a suitable approximation of the first moment for cases beyond the weak phase object approximation. It is found that the measurement of momentum transfers using segmented detectors can approach the first moment measurement as close as 0.13 h/nm in terms of a root mean square (rms) difference in 10 nm thick SrTiO3 for a detector with 16 segments. This amounts to 35% of the rms of the momentum transfers. In addition, we present a statistical analysis of the precision of first moment STEM as a function of dose. For typical experimental settings with recent hardware such as a Medipix3 Merlin camera attached to a probe-corrected STEM, we find that the precision of the measurement of momentum transfers stagnates above certain doses. This means that other instabilities such as specimen drift or scan noise have to be taken into account seriously for measurements that target, e.g., the detection of bonding effects in the charge density. |
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Wos |
000465021000013 |
Publication Date |
2018-12-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
25 |
Open Access |
OpenAccess |
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Notes |
; The direct electron detector (Medipix3 Merlin) was funded by the Hercules fund from the Flemish Government. K. Muller-Caspary acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the framework of the Helmholtz Young Investigator Group moreSTEM (VH-NG-1317) at Forschungszentrum Julich, Germany. F. F. Krause acknowledges funding from the Central Research Development Fund of the University of Bremen, Germany. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) and the Research Fund of the University of Antwerp. ; |
Approved |
Most recent IF: 2.843 |
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Call Number |
UA @ admin @ c:irua:160213 |
Serial |
5242 |
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Author |
Susi, T.; Madsen, J.; Ludacka, U.; Mortensen, J.J.; Pennycook, T.J.; Lee, Z.; Kotakoski, J.; Kaiser, U.; Meyer, J.C. |
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Title |
Efficient first principles simulation of electron scattering factors for transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
197 |
Issue |
197 |
Pages |
16-22 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Electron microscopy is a powerful tool for studying the properties of materials down to their atomic structure. In many cases, the quantitative interpretation of images requires simulations based on atomistic structure models. These typically use the independent atom approximation that neglects bonding effects, which may, however, be measurable and of physical interest. Since all electrons and the nuclear cores contribute to the scattering potential, simulations that go beyond this approximation have relied on computationally highly demanding all-electron calculations. Here, we describe a new method to generate ab initio electrostatic potentials when describing the core electrons by projector functions. Combined with an interface to quantitative image simulations, this implementation enables an easy and fast means to model electron scattering. We compare simulated transmission electron microscopy images and diffraction patterns to experimental data, showing an accuracy equivalent to earlier all-electron calculations at a much lower computational cost. |
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Wos |
000456311700003 |
Publication Date |
2018-11-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
3 |
Open Access |
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| |
Notes |
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Approved |
Most recent IF: 2.843 |
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Call Number |
UA @ admin @ c:irua:165938 |
Serial |
6296 |
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| Permanent link to this record |
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Author |
Pennycook, T.J.; Martinez, G.T.; Nellist, P.D.; Meyer, J.C. |
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Title |
High dose efficiency atomic resolution imaging via electron ptychography |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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| |
Volume |
196 |
Issue |
196 |
Pages |
131-135 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Radiation damage places a fundamental limitation on the ability of microscopy to resolve many types of materials at high resolution. Here we evaluate the dose efficiency of phase contrast imaging with electron ptychography. The method is found to be far more resilient to temporal incoherence than conventional and spherical aberration optimized phase contrast imaging, resulting in significantly greater clarity at a given dose. This robustness is explained by the presence of achromatic lines in the four dimensional ptychographic dataset. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000451180800018 |
Publication Date |
2018-10-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.843 |
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Call Number |
UA @ admin @ c:irua:165939 |
Serial |
6301 |
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| Permanent link to this record |
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Author |
Leuthner, G.T.; Hummel, S.; Mangler, C.; Pennycook, T.J.; Susi, T.; Meyer, J.C.; Kotakoski, J. |
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Title |
Scanning transmission electron microscopy under controlled low-pressure atmospheres |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
203 |
Issue |
203 |
Pages |
76-81 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Transmission electron microscopy (TEM) is carried out in vacuum to minimize the interaction of the imaging electrons with gas molecules while passing through the microscope column. Nevertheless, in typical devices, the pressure remains at 10(-7) mbar or above, providing a large number of gas molecules for the electron beam to crack, which can lead to structural changes in the sample. Here, we describe experiments carried out in a modified scanning TEM (STEM) instrument, based on the Nion UltraSTEM 100. In this instrument, the base pressure at the sample is around 2 x 10(-10 )mbar, and can be varied up to 10(-6) mbar through introduction of gases directly into the objective area while maintaining atomic resolution imaging conditions. We show that air leaked into the microscope column during the experiment is efficient in cleaning graphene samples from contamination, but ineffective in damaging the pristine lattice. Our experiments also show that exposure to O(2 )and H2O lead to a similar result, oxygen providing an etching effect nearly twice as efficient as water, presumably due to the two 0 atoms per molecule. H(2 )and N-2 environments have no influence on etching. These results show that the residual gas environment in typical TEM instruments can have a large influence on the observations, and show that chemical etching of carbon-based structures can be effectively carried out with oxygen. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000465021000010 |
Publication Date |
2019-02-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
4 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.843 |
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Call Number |
UA @ admin @ c:irua:165937 |
Serial |
6321 |
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| Permanent link to this record |
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Author |
Einhäupl, P.V.; Krook, J.; Svensson, N.; Van Acker, K.; Van Passel, S. |
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Title |
Eliciting stakeholder needs : an anticipatory approach assessing enhanced landfill mining |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Waste Management |
Abbreviated Journal |
Waste Manage |
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| |
Volume |
98 |
Issue |
98 |
Pages |
113-125 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM) |
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Abstract |
Landfill owners, governmental institutions, technology providers, academia and local communities are important stakeholders involved in Enhanced Landfill Mining (ELFM). This concept of excavating and processing historical waste streams to higher added values can be seen as a continuation of traditional landfill mining (LFM) and seems to be an innovative and promising idea for potential environmental and societal benefits. However, ELFM's profitability is still under debate, and environmental as well as societal impacts have to be further investigated. This study provides a first step towards an anticipatory approach, assessing ELFM through stakeholder integration. In the study, semi-structured interviews were conducted with various stakeholders, involved in a case study in Flanders, Belgium. Participants were selected across a quadruple helix (QH) framework, i.e. industrial, governmental, scientific, and local community actors. The research comprises 13 interviews conducted with an aim to elicit stakeholder needs for ELFM implementation using a general inductive approach. In total 18 different stakeholder needs were identified. The paper explains how the stakeholder needs refer to the different dimensions of sustainability, which groups of stakeholders they primarily affect, and what types of uncertainty could be influenced by their implementation. The stakeholder needs are structured into societal, environmental, regulatory and techno-economic needs. Results show additional economic, environmental, and societal aspects of ELFM to be integrated into ELFM research, as well as a need for the dynamic modeling of impacts. (C) 2019 Elsevier Ltd. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000487175500012 |
Publication Date |
2019-08-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0956-053x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.03 |
Times cited |
3 |
Open Access |
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Notes |
; This project has received funding from the European Union's EU Framework Programme for Research and Innovation Horizon 2020 under Grant Agreement No 721185. ; |
Approved |
Most recent IF: 4.03 |
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Call Number |
UA @ admin @ c:irua:163760 |
Serial |
6193 |
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| Permanent link to this record |
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Author |
Sakarika, M.; Spiller, M.; Baetens, R.; Donies, G.; Vanderstuyf, J.; Vinck, K.; Vrancken, K.C.; Van Barel, G.; Du Bois, E.; Vlaeminck, S.E. |
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Title |
Proof of concept of high-rate decentralized pre-composting of kitchen waste : optimizing design and operation of a novel drum reactor |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Waste management |
Abbreviated Journal |
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Volume |
91 |
Issue |
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Pages |
20-32 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Product development |
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Abstract |
Each ton of organic household waste that is collected, transported and composted incurs costs (€75/ton gate fee). Reducing the mass and volume of kitchen waste (
KW) at the point of collection can diminish transport requirements and associated costs, while also leading to an overall reduction in gate fees for final processing. To this end, the objective of this research was to deliver a proof of concept for the so-called “urban pre-composter”; a bioreactor for the decentralized, high-rate pre-treatment of KW, that aims at mass and volume reduction at the point of collection. Results show considerable reductions in mass (33%), volume (62%) and organic solids (32%) of real KW, while provision of structure material and separate collection of leachate was found to be unnecessary. The temperature profile, C/N ratio (12) and VS/TS ratio (0.69) indicated that a mature compost can be produced in 68 days (after pre-composting and main composting). An economic Monte Carlo simulation yielded that the urban pre-composter concept is not more expensive than the current approach, provided its cost per unit is €8,000–€14,500 over a 10-year period (OPEX and CAPEX, in 80% of the cases). The urban pre-composter is therefore a promising system for the efficient pre-treatment of organic household waste in an urban context. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000473378700003 |
Publication Date |
2019-04-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0956-053x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:159579 |
Serial |
8426 |
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| Permanent link to this record |
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Author |
Wardenier, N.; Gorbanev, Y.; Van Moer, I.; Nikiforov, A.; Van Hulle, S.W.H.; Surmont, P.; Lynen, F.; Leys, C.; Bogaerts, A.; Vanraes, P. |
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Title |
Removal of alachlor in water by non-thermal plasma: Reactive species and pathways in batch and continuous process |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
Water Res |
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Volume |
161 |
Issue |
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Pages |
549-559 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Pesticides are emerging contaminants frequently detected in the aquatic environment. In this work, a novel approach combining activated carbon adsorption, oxygen plasma treatment and ozonation was studied for the removal of the persistent chlorinated pesticide alachlor. A comparison was made between the removal efficiency and energy consumption for two different reactor operation modes: batchrecirculation and single-pass mode. The kinetics study revealed that the insufficient removal of alachlor by adsorption was significantly improved in terms of degradation efficiency and energy consumption when combined with the plasma treatment. The best efficiency (ca. 80% removal with an energy cost of 19.4 kWh mÀ3) was found for the single-pass operational mode of the reactor. In the batch-recirculating process, a complete elimination of alachlor by plasma treatment was observed after 30 min of treatment. Analysis of the reactive species induced by plasma in aqueous solutions showed that the decomposition of alachlor mainly occurred through a radical oxidation mechanism, with a minor contribution of long-living oxidants (O3, H2O2). Investigation of the alachlor oxidation pathways revealed six different oxidation mechanisms, including the loss of aromaticity which was never before reported for plasma-assisted degradation of aromatic pesticides. It was revealed that the removal rate and energy cost could be further improved with more than 50% by additional O3 gas bubbling in the solution reservoir. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000475999400054 |
Publication Date |
2019-06-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0043-1354 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.942 |
Times cited |
2 |
Open Access |
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Notes |
PlasmaTex project IWT, 1408/2 ; the European Marie Sklodowska-Curie Individual Fellowship within Horizon2020, 743151 ; Flemish Knowledge Centre Water; This work was financially supported by the PlasmaTex project IWT 1408/2 and the European Marie Sklodowska-Curie Individual Fellowship within Horizon2020 (‘LTPAM’, grant no. 743151). This research was initiated within the LED H2O project which is financially supported by the Flemish Knowledge Centre Water (Vlakwa). |
Approved |
Most recent IF: 6.942 |
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Call Number |
PLASMANT @ plasmant @c:irua:161173 |
Serial |
5288 |
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| Permanent link to this record |
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Author |
Vanderkerckhove, T.G.L.; Kerckhof, F.-M.; De Mulder, C.; Vlaeminck, S.E.; Boon, N. |
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Title |
Determining stoichiometry and kinetics of two thermophilic nitrifying communities as a crucial step in the development of thermophilic nitrogen removal |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
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Volume |
156 |
Issue |
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Pages |
34-45 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Nitrification and denitrification, the key biological processes for thermophilic nitrogen removal, have separately been established in bioreactors at 50 °C. A well-characterized set of kinetic parameters is essential to integrate these processes while safeguarding the autotrophs performing nitrification. Knowledge on thermophilic nitrifying kinetics is restricted to isolated or highly enriched batch cultures, which do not represent bioreactor conditions. This study characterized the stoichiometry and kinetics of two thermophilic (50 °C) nitrifying communities. The most abundant ammonia oxidizing archaea (AOA) were related to the Nitrososphaera genus, clustering relatively far from known species Nitrososphaera gargensis (95.5% 16S rRNA gene sequence identity). The most abundant nitrite oxidizing bacteria (NOB) were related to Nitrospira calida (97% 16S rRNA gene sequence identity). The nitrification biomass yield was 0.200.24 g VSS g−1 N, resulting mainly from a high AOA yield (0.160.20 g VSS g−1 N), which was reflected in a high AOA abundance in the community (5776%) compared to NOB (511%). Batch-wise determination of decay rates (AOA: 0.230.29 d−1; NOB: 0.320.43 d−1) rendered an overestimation compared to in situ estimations of overall decay rate (0.0260.078 d−1). Possibly, the inactivation rate rather than the actual decay rate was determined in batch experiments. Maximum growth rates of AOA and NOB were 0.120.15 d−1 and 0.130.33 d−1 respectively. NOB were susceptible to nitrite, opening up opportunities for shortcut nitrogen removal. However, NOB had a similar growth rate and oxygen affinity (0.150.55 mg O2 L−1) as AOA and were resilient towards free ammonia (IC50 > 16 mg NH3-N L−1). This might complicate NOB outselection using common practices to establish shortcut nitrogen removal (SRT control; aeration control; free ammonia shocks). Overall, the obtained insights can assist in integrating thermophilic conversions and facilitate single-sludge nitrification/denitrification. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000466618400004 |
Publication Date |
2019-03-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0043-1354; 1879-2448 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:158226 |
Serial |
7798 |
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| Permanent link to this record |
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Author |
Alloul, A.; Wuyts, S.; Lebeer, S.; Vlaeminck, S.E. |
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Title |
Volatile fatty acids impacting phototrophic growth kinetics of purple bacteria : paving the way for protein production on fermented wastewater |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
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Volume |
152 |
Issue |
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Pages |
138-147 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Nutrient losses in our food chain severely surpass our planetary boundaries. Resource recovery can contribute to mitigation, for instance through converting wastewater resources to microbial protein for animal feed. Wastewater typically holds a complex mixture of organics, posing a challenge to selectively produce heterotrophic biomass. Ensuring the product's quality could be achieved by anaerobic generation of volatile fatty acids (VFAs) followed by photoheterotrophic production of purple non-sulfur bacteria (PNSB) with infrared light. This study aimed to determine the most suitable PNSB culture for VFA conversion and map the effect of acetate, propionate, butyrate and a VFA mixture on growth and biomass yield. Six cultures were screened in batch: (i) Rhodopseudomonas palustris, (ii) Rhodobacter sphaeroides, (iii) Rhodospirillum rubrum, (iv) a 3-species synthetic community (i+ii+iii), (v) a community enriched on VFA holding Rb. capsulatus, and (vi) Rb. capsulatus (isolate v). The VFA mixture elevated growth rates with a factor 1.32.5 compared to individual VFA. Rb. capsulatus showed the highest growth rates: 1.82.2 d−1 (enriched) and 2.33.8 d−1 (isolated). In a photobioreactor (PBR) inoculated with the Rb. capsulatus enrichment, decreasing sludge retention time (SRT) yielded lower biomass concentrations, yet increased productivities, reaching 1.7 g dry weight (DW) L−1 d−1, the highest phototrophic rate reported thus far, and a growth rate of up to 5 d−1. PNSB represented 2657% of the community and the diversity index was low (37), with a dominance of Rhodopseudomonas at long SRT and Rhodobacter at short SRT. The biomass yield for all cultures, in batch and reactor cultivation, approached 1 g CODBiomass g−1 CODRemoved. An economic estimation for a two-stage approach on brewery wastewater (load 2427 kg COD d−1) showed that 0.5 d SRT allowed for the lowest production cost ( 10 kg−1 DW; equal shares for capex and opex). The findings strengthen the potential for a novel two-stage approach for resource recovery from industrial wastewater, enabling high-rate PNSB production. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000458223900013 |
Publication Date |
2018-12-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0043-1354; 1879-2448 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:156462 |
Serial |
8739 |
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| Permanent link to this record |
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Author |
Amato, S.R.; Burnstock, A.; Cross, M.; Janssens, K.; Rosi, F.; Cartechini, L.; Fontana, R.; Dal Fovo, A.; Paolantoni, M.; Grazia, C.; Romani, A.; Michelin, A.; Andraud, C.; Tournie, A.; Dik, J. |
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Title |
Interpreting technical evidence from spectral imaging of paintings by Edouard Manet in the Courtauld Gallery |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
X-ray spectrometry
T2 – MA-XRF Workshop on Developments and Applications of Macro-XRF in, Conservation, Art, and Archeology, SEP 24-25, 2017, Trieste, ITALY |
Abbreviated Journal |
X-Ray Spectrom |
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Volume |
48 |
Issue |
4 |
Pages |
282-292 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The paintings by edouard Manet in The Courtauld Gallery Dejeuner sur l'herbe (1863-68), Marguerite de Conflans en Toilette de Bal (1870-1880), Banks of the Seine at Argenteuil (1874), and A Bar at the Folies-Bergere (1882) were investigated for the first time using a range of non-invasive in situ analyses. The aims of the study were to investigate the painting techniques and materials used for this group of works and to critically evaluate the technical evidence derived from the integrated use of imaging techniques and portable spectroscopic methods in this context. The paintings were investigated by means of macro X-ray fluorescence (MA-XRF), reflection spectral imaging, portable UV-Vis-NIR spectroscopy, portable Raman spectroscopy, and reflection FTIR. MA-XRF and reflection spectral imaging allowed visualising elements in the compositions that were not visible using traditional methods of technical study. For example, MA-XRF analysis of Dejeuner sur l'herbe revealed elements of the development of the composition that provided new evidence to consider its relationship to other versions of the composition. The study also highlighted questions about the interpretation of elemental distribution maps and spectral images that did not correspond to the reworking visible in X-radiographs. For example, in A Bar at the Folies-Bergere Manet made numerous changes during painting, which were not clearly visualised with any of the techniques used. The research has wider implications for the study of Impressionist paintings, as the results will support technical studies of works by other artists of the period who used similar materials and painting methods. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000472210700005 |
Publication Date |
2018-01-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0049-8246 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.298 |
Times cited |
|
Open Access |
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Notes |
; Financial support by the Access to Research Infrastructures activity in the Horizon 2020 Programme of the EU (IPERION CH Grant agreement 654028) is gratefully acknowledged. ; |
Approved |
Most recent IF: 1.298 |
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Call Number |
UA @ admin @ c:irua:161296 |
Serial |
5670 |
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| Permanent link to this record |
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Author |
Moldovan, D.; Masir, M.R.; Peeters, F.M. |
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Title |
Magnetic field dependence of the atomic collapse state in graphene |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
5 |
Issue |
1 |
Pages |
015017 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
<script type='text/javascript'>document.write(unpmarked('Quantum electrodynamics predicts that heavy atoms (Z \u003E Z(c) approximate to 170) will undergo the process of atomic collapse where electrons sink into the positron continuum and a new family of so-called collapsing states emerges. The relativistic electrons in graphene exhibit the same physics but at a much lower critical charge (Z(c) approximate to 1) which has made it possible to confirm this phenomenon experimentally. However, there exist conflicting predictions on the effect of a magnetic field on atomic collapse. These theoretical predictions are based on the continuum Dirac-Weyl equation, which does not have an exact analytical solution for the interplay of a supercritical Coulomb potential and the magnetic field. Approximative solutions have been proposed, but because the two effects compete on similar energy scales, the theoretical treatment varies depending on the regime which is being considered. These limitations are overcome here by starting from a tight-binding approach and computing exact numerical results. By avoiding special limit cases, we found a smooth evolution between the different regimes. We predict that the atomic collapse effect persists even after the magnetic field is activated and that the critical charge remains unchanged. We show that the atomic collapse regime is characterized: (1) by a series of Landau level anticrossings and (2) by the absence of root B scaling of the Landau levels with regard to magnetic field strength.')); |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000415015000001 |
Publication Date |
2017-10-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2053-1583 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
13 |
Open Access |
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Notes |
; We thank Eva Andrei, Jinhai Mao and Yuhang Jiang for insightful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish Government. ; |
Approved |
Most recent IF: 6.937 |
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Call Number |
UA @ lucian @ c:irua:147361UA @ admin @ c:irua:147361 |
Serial |
4884 |
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| Permanent link to this record |
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Author |
Shah, J.; Wang, W.; Bogaerts, A.; Carreon, M.L. |
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Title |
Ammonia Synthesis by Radio Frequency Plasma Catalysis: Revealing the Underlying Mechanisms |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ACS applied energy materials |
Abbreviated Journal |
ACS Appl. Energy Mater. |
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| |
Volume |
1 |
Issue |
9 |
Pages |
4824-4839 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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| |
Abstract |
Nonthermal plasma is a promising alternative for ammonia synthesis at gentle conditions. Metal meshes of Fe, Cu, Pd, Ag, and Au were employed as catalysts in radio frequency plasma for ammonia synthesis. The energy yield for all these transition metal catalysts ranged between 0.12 and 0.19 g-NH3/kWh at 300 W and, thus, needs further improvement. In addition, a semimetal, pure gallium, was used for the first time as catalyst for ammonia synthesis, with energy yield of 0.22 g-NH3/kWh and with a maximum yield of ∼10% at 150 W. The emission spectra, as well as computer simulations, revealed hydrogen recombination as a primary governing parameter, which depends on the concentration or flux of H atoms in the plasma and on the catalyst surface. The simulations helped to elucidate the underlying mechanism, implicating the dominance of surface reactions and surface adsorbed species. The rate limiting step appears to be NH2 formation on the surface of the reactor wall and on the catalyst surface, which is different from classical catalysis. |
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Wos |
000458706500048 |
Publication Date |
2018-09-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2574-0962 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access |
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Notes |
M.L.C. acknowledges financial support from The University of Tulsa Faculty Startup Funds and The University of Tulsa Faculty Development Summer Fellowship Grant (FDSF). A.B. acknowledges financial support from the Excellence of Science program of the Fund for Scientific Research (FWO-FNRS; Grant no. G0F91618N; EOS ID 30505023). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. |
Approved |
Most recent IF: NA |
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Call Number |
PLASMANT @ plasmant @c:irua:153804 |
Serial |
5051 |
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| Permanent link to this record |
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Author |
Alexander, C.T.; Abakumov, A.M.; Forslund, R.P.; Johnston, K.P.; Stevenson, K.J. |
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Title |
Role of the carbon support on the oxygen reduction and evolution activities in LaNiO3 composite electrodes in alkaline solution |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ACS applied energy materials |
Abbreviated Journal |
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| |
Volume |
1 |
Issue |
4 |
Pages |
1549-1558 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Metal-air batteries and fuel cells show a great deal of promise in advancing low-cost, high-energy-density charge storage solutions for sustainable energy applications. To improve the activities and stabilities of electrocatalysts for the critical oxygen reduction and evolution reactions (ORR and OER, respectively), a greater understanding is needed of the catalyst/carbon interactions and carbon stability. Herein, we report how LaNiO3 (LNO) supported on nitrogen-doped carbon nanotubes (N-CNT) made from a high-yield synthesis lowers the overpotential for both the OER and ORR markedly to enable a low bifunctional window of 0.81 V at only a 51 mu g cm(-2) mass loading. Furthermore, the addition of LNO to the N-CNTs improves the galvanostatic stability for the OER by almost 2 orders of magnitude. The nanoscale geometries of the perovskites and the CNTs enhance the number of metal-support and charge transfer interactions and thus the activity. We use rotating ring disk electrodes (RRDEs) combined with Tafel slope analysis and ICP-OES to quantitatively separate current contributions from the OER, carbon oxidation, and even anodic iron leaching from carbon nanotubes. |
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Place of Publication |
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Wos |
000458705400020 |
Publication Date |
2018-03-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2574-0962 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:157642 |
Serial |
8487 |
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| Permanent link to this record |
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Author |
Wu, J.; Zhang, L.; Xin, X.; Zhang, Y.; Wang, H.; Sun, A.; Cheng, Y.; Chen, X.; Xu, G. |
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Title |
Electrorheological fluids with high shear stress based on wrinkly tin titanyl oxalate |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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| |
Volume |
10 |
Issue |
7 |
Pages |
6785-6792 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Electrorheological (ER) fluids are considered as a type of smart fluids because their rheological characteristics can be altered through an electric field. The discovery of giant ER effect revived the researchers' interest in the ER technological area. However, the poor stability including the insufficient dynamic shear stress, the large leakage current density, and the sedimentation tendency still hinders their practical applications. Herein, we report a facile and scalable coprecipitation method for synthesizing surfactant-free tin titanyl oxalate (TTO) particles with tremella-like wrinkly microstructure (W-TTO). The W-TTO-based ER fluids exhibit enhanced ER activity compared to that of the pristine TTO because of the improved wettability between W-TTO and the silicone oil. In addition, the static yield stress and leakage current of W-TTO ER fluids also show a fine time stability during the 30 day tests. More importantly, the dynamic shear stress of W-TTO ER fluids can remain stable throughout the shear rate range, which is valuable for their use in engineering applications. The results in this work provided a promising strategy to solving the long-standing problem of ER fluid stability. Moreover, this convenient route of synthesis may be considered a green approach for the mass production of giant ER materials. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Language |
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Wos |
000426143900081 |
Publication Date |
2018-02-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1944-8244 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
7 |
Open Access |
OpenAccess |
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Notes |
; The work was supported by the National Natural Science Foundation of China (Grant 21573267, 11674335), the Youth Innovation Promotion Association CAS (2013196), and the Program for Ningbo Municipal Science and Technology Innovative Research Team (2015B11002, 2016B10005). ; |
Approved |
Most recent IF: 7.504 |
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| |
Call Number |
UA @ lucian @ c:irua:149911 |
Serial |
4931 |
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| Permanent link to this record |
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Author |
Ben Dkhil, S.; Pfannmöller, M.; Schroeder, R.R.; Alkarsifi, R.; Gaceur, M.; Koentges, W.; Heidari, H.; Bals, S.; Margeat, O.; Ackermann, J.; Videlot-Ackermann, C. |
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Title |
Interplay of interfacial layers and blend composition to reduce thermal degradation of polymer solar cells at high temperature |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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| |
Volume |
10 |
Issue |
10 |
Pages |
3874-3884 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The thermal stability of printed polymer solar cells at elevated temperatures needs to be improved to achieve high-throughput fabrication including annealing steps as well as long-term stability. During device processing, thermal annealing impacts both the organic photoactive layer, and the two interfacial layers make detailed studies of degradation mechanism delicate. A recently identified thermally stable poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b'-dithiopherie-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b]thiophenediyl]] : [6,6]-phenyl- C-71-butyric acid methyl ester (PTB7:PC70BM) blend as photoactive layer in combination with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate as hole extraction layer is used here to focus on the impact of electron extraction layer (EEL) on the thermal stability of solar cells. Solar cells processed with densely packed ZnO nanoparticle layers still show 92% of the initial efficiency after constant annealing during 1 day at 140 degrees C, whereas partially covering ZnO layers as well as an evaporated calcium layer leads to performance losses of up to 30%. This demonstrates that the nature and morphology of EELs highly influence the thermal stability of the device. We extend our study to thermally unstable PTB7:[6,6]-phenyl-C-61-butyric acid methyl ester (PC60BM) blends to highlight the impact of ZnO on the device degradation during annealing. Importantly, only 12% loss in photocurrent density is observed after annealing at 140 degrees C during 1 day when using closely packed ZnO. This is in stark contrast to literature and addressed here to the use of a stable double-sided confinement during thermal annealing. The underlying mechanism of the inhibition of photocurrent losses is revealed by electron microscopy imaging and spatially resolved spectroscopy. We found that the double-sided confinement suppresses extensive fullerene diffusion during the annealing step, but with still an increase in size and distance of the enriched donor and acceptor domains inside the photoactive layer by an average factor of 5. The later result in combination with comparably small photocurrent density losses indicates the existence of an efficient transport of minority charge carriers inside the donor and acceptor enriched phases in PTB7:PC60BM blends. |
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Corporate Author |
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Place of Publication |
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Wos |
000424728800082 |
Publication Date |
2018-01-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1944-8244 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
9 |
Open Access |
OpenAccess |
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Notes |
; We acknowledge the financial support by the French Fond Unique Interministeriel (FUI) under the project “SFUMATO” (grant number: F1110019V/201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7-contract number: 287594). M.P. and R.R.S. acknowledge support by the HeiKA (Heidelberg Karlsruhe Research Partnership) FunTech-3D materials science program. ; |
Approved |
Most recent IF: 7.504 |
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Call Number |
UA @ lucian @ c:irua:149309UA @ admin @ c:irua:149309 |
Serial |
4939 |
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| Permanent link to this record |
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Author |
Wang, Z.; Zhang, Y.; Neyts, E.C.; Cao, X.; Zhang, X.; Jang, B.W.-L.; Liu, C.-jun |
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Title |
Catalyst preparation with plasmas : how does it work? |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
ACS catalysis |
Abbreviated Journal |
Acs Catal |
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Volume |
8 |
Issue |
3 |
Pages |
2093-2110 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Catalyst preparation with plasmas is increasingly attracting interest. A plasma is a partially ionized gas, consisting of electrons, ions, molecules, radicals, photons, and excited species, which are all active species for catalyst preparation and treatment. Under the influence of plasma, nucleation and crystal growth in catalyst preparation can be very different from those in the conventional thermal approach. Some thermodynamically unfavorable reactions can easily take place with plasmas. Compounds such as sulfides, nitrides, and phosphides that are produced under harsh conditions can be synthesized by plasma under mild conditions. Plasmas can produce catalysts with smaller particle sizes and controllable structure. Plasma is also a facile tool for reduction, oxidation, doping, etching, coating, alloy formation, surface treatment, and surface cleaning in a simple and direct way. A rapid and convenient plasma template removal has thus been established for zeolite synthesis. It can operate at room temperature and allows the catalyst preparation on temperature-sensitive supporting materials. Plasma is typically effective for the production of various catalysts on metallic substrates. In addition, plasma-prepared transition-metal catalysts show enhanced low-temperature activity with improved stability. This provides a useful model catalyst for further improvement of industrial catalysts. In this review, we aim to summarize the recent advances in catalyst preparation with plasmas. The present understanding of plasma-based catalyst preparation is discussed. The challenges and future development are addressed. |
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Corporate Author |
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Thesis |
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Publisher |
Amer chemical soc |
Place of Publication |
Washington |
Editor |
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Language |
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Wos |
000426804100055 |
Publication Date |
2018-01-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2155-5435 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
10.614 |
Times cited |
81 |
Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 10.614 |
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Call Number |
UA @ lucian @ c:irua:150880 |
Serial |
4963 |
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| Permanent link to this record |
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Author |
Theofanidis, S.A.; Galvita, V.V.; Poelman, H.; Dharanipragada, N.V.R.A.; Longo, A.; Meledina, M.; Van Tendeloo, G.; Detavernier, C.; Marin, G.B. |
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Title |
Fe-containing magnesium aluminate support for stability and carbon control during methane reforming |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
ACS catalysis |
Abbreviated Journal |
Acs Catal |
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Volume |
8 |
Issue |
7 |
Pages |
5983-5995 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We report a MgFexAl2-xO4 synthetic spinel, where x varies from 0 to 0.26, as support for Ni-based catalysts, offering stability and carbon control under various conditions of methane reforming. By incorporation of Fe into a magnesium aluminate spine!, a support is created with redox functionality and high thermal stability, as concluded from temporal analysis of products (TAP) experiments and redox cycling, respectively. A diffusion coefficient of 3 x 10(-17) m(2) s(-1) was estimated for lattice oxygen at 993 K from TAP experiments. X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) modeling identified that the incorporation of iron occurs as Fe3+ in the octahedral sites of the spinel lattice, replacing aluminum. Simulation of the X-ray absorption near edge structure (XANES) spectrum of the reduced support showed that 60 +/- 10% of iron was reduced from 3+ to 2+ at 1073 K, while there was no formation of metallic iron. A series of Ni/MgFexAl2-xO4 catalysts, where x varies from 0 to 0.26, was synthesized and reduced, yielding a supported Ni-Fe alloy. The evolution of the catalyst structure during H-2 temperature-programmed reduction (TPR) and CO2 temperature-programmed oxidation (TPO) was examined using time-resolved in situ XRD and XANES. During reforming, iron in both the support and alloy keeps control of carbon accumulation, as confirmed by O-2-TPO on the spent catalysts. By fine tuning the amount of Fe in MgFexAl2-xO4, a supported alloy was obtained with a Ni/Fe molar ratio of similar to 10, which was active for reforming and stable. By comparison of the performance of Ni-based catalysts with Fe either incorporated into or deposited onto the support, the location of Fe within the support proved crucial for the stability and carbon mitigation under reforming conditions. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor |
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Wos |
000438475100034 |
Publication Date |
2018-05-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2155-5435 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
10.614 |
Times cited |
18 |
Open Access |
OpenAccess |
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Notes |
; This work was supported by the FAST industrialization by Catalyst Research and Development (FASTCARD) project, which is a Large Scale Collaborative Project supported by the European Commission in the 7th Framework Programme (GA no 604277), the “Long Term Structural Methusalem Funding by the Flemish Government”, the Interuniversity Attraction Poles Programme, IAP7/5, Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) in supplying financing of travel costs and beam time at the DUBBLE beamline of the ESRF. The authors acknowledge the assistance from the DUBBLE (ESRF, XAS campaign 26-01-1048) and ROCK staff (SOLEIL, proposal 201502561). The authors equally acknowledge support from a public grant overseen by the French National Research Agency (ANR) as part of the “Investissements d'Avenir” program (reference: ANR-10-EQPX-45) for the ROCK beamline and from Lukas Buelens and Rakesh Batchu (Laboratory for Chemical Technology, Ghent University) for the STEM measurements and TAP experiments, respectively. ; |
Approved |
Most recent IF: 10.614 |
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Call Number |
UA @ lucian @ c:irua:153178 |
Serial |
5102 |
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| Permanent link to this record |
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Author |
Bogaerts, A.; Neyts, E.C. |
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Title |
Plasma Technology: An Emerging Technology for Energy Storage |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
ACS energy letters |
Abbreviated Journal |
Acs Energy Lett |
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Volume |
3 |
Issue |
4 |
Pages |
1013-1027 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma technology is gaining increasing interest for gas conversion applications, such as CO2 conversion into value-added chemicals or renewable fuels, and N2 fixation from the air, to be used for the production of small building blocks for, e.g., mineral fertilizers. Plasma is generated by electric power and can easily be switched on/off, making it, in principle, suitable for using intermittent renewable electricity. In this Perspective article, we explain why plasma might be promising for this application. We briefly present the most common types of plasma reactors with their characteristic features, illustrating why some plasma types exhibit better energy efficiency than others. We also highlight current research in the fields of CO2 conversion (including the combined conversion of CO2 with CH4, H2O, or H2) as well as N2 fixation (for NH3 or NOx synthesis). Finally, we discuss the major limitations and steps to be taken for further improvement. |
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Corporate Author |
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Place of Publication |
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Wos |
000430369600035 |
Publication Date |
2018-04-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2380-8195 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
56 |
Open Access |
OpenAccess |
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Notes |
Universiteit Antwerpen, TOP research project 32249 ; Fonds Wetenschappelijk Onderzoek, G.0217.14N G.0254.14N G.0383.16N ; |
Approved |
Most recent IF: NA |
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Call Number |
PLASMANT @ plasmant @c:irua:150358 |
Serial |
4919 |
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Author |
Yang, C.; Batuk, M.; Jacquet, Q.; Rousse, G.; Yin, W.; Zhang, L.; Hadermann, J.; Abakumov, A.M.; Cibin, G.; Chadwick, A.; Tarascon, J.-M.; Grimaud, A. |
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Title |
Revealing pH-Dependent Activities and Surface Instabilities for Ni-Based Electrocatalysts during the Oxygen Evolution Reaction |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
ACS energy letters |
Abbreviated Journal |
Acs Energy Lett |
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Volume |
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Issue |
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Pages |
2884-2890 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Multiple electrochemical processes are involved at the catalyst/ electrolyte interface during the oxygen evolution reaction (OER). With the purpose of elucidating the complexity of surface dynamics upon OER, we systematically studied two Ni-based crystalline oxides (LaNiO3−δ and La2Li0.5Ni0.5O4) and compared them with the state-of-the-art Ni−Fe (oxy)- hydroxide amorphous catalyst. Electrochemical measurements such as rotating ring disk electrode (RRDE) and electrochemical quartz microbalance microscopy (EQCM) coupled with a series of physical characterizations including transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS) were conducted to unravel the exact pH effect on both the OER activity and the catalyst stability. We demonstrate that for Ni-based crystalline catalysts the rate for surface degradation depends on the pH and is greater than the rate for surface reconstruction. This behavior is unlike that for the amorphous Ni oxyhydroxide catalyst, which is found to be more stable and pH-independent. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000453805100005 |
Publication Date |
2018-11-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2380-8195 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access: Available from 06.11.2019
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Notes |
C.Y., J.-M.T., and A.G. acknowledge funding from the European Research Council (ERC) (FP/2014)/ERC GrantProject 670116-ARPEMA. A.G. acknowledges financial support from the ANR MIDWAY (Project ID ANR-17-CE05- 0008). We acknowledge Diamond Light Source for time awarded to the Energy Materials BAG on Beamline B18, under Proposal sp12559. |
Approved |
Most recent IF: NA |
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Call Number |
EMAT @ emat @c:irua:155046 |
Serial |
5067 |
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| Permanent link to this record |
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Author |
Sandoval, S.; Kepic, D.; Perez del Pino, A.; Gyorgy, E.; Gomez, A.; Pfannmöller, M.; Van Tendeloo, G.; Ballesteros, B.; Tobias, G. |
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Title |
Selective laser-assisted synthesis of tubular van der Waals heterostructures of single-layered PbI2 within carbon nanotubes exhibiting carrier photogeneration |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
12 |
Issue |
7 |
Pages |
6648-6656 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The electronic and optical properties of two-dimensional layered materials allow the miniaturization of nanoelectronic and optoelectronic devices in a competitive manner. Even larger opportunities arise when two or more layers of different materials are combined. Here, we report on an ultrafast energy efficient strategy, using laser irradiation, which allows bulk synthesis of crystalline single-layered lead iodide in the cavities of carbon nanotubes by forming cylindrical van der Waals heterostructures. In contrast to the filling of van der Waals solids into carbon nanotubes by conventional thermal annealing, which favors the formation of inorganic nanowires, the present strategy is highly selective toward the growth of monolayers forming lead iodide nanotubes. The irradiated bulk material bearing the nanotubes reveals a decrease of the resistivity as well as a significant increase in the current flow upon illumination. Both effects are attributed to the presence of single-walled lead iodide nanotubes in the cavities of carbon nanotubes, which dominate the properties of the whole matrix. The present study brings in a simple, ultrafast and energy efficient strategy for the tailored synthesis of rolled-up single-layers of lead iodide (i.e., single-walled PbI2 nanotubes), which we believe could be expanded to other two-dimensional (2D) van der Waals solids. In fact, initial tests with ZnI2 already reveal the formation of single-walled ZnI2 nanotubes, thus proving the versatility of the approach. |
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Wos |
000440505000029 |
Publication Date |
2018-07-05 |
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ISSN |
1936-0851 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
8 |
Open Access |
OpenAccess |
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Notes |
; We acknowledge funding from MINECO (Spain), through MAT2017-86616-R, ENE2017-89210-C2-1-R, and “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0496, SEV-2013-0295), CERCA programme for funding ICN2 and support from AGAUR of Generalitat de Catalunya through the projects 2017 SGR 1086, 2017 SGR 581 and 2017 SGR 327. We thank Thomas Swan Co., Ltd., for supplying MWCNT Elicarb samples. D.K. acknowledges financial support from the Ministry of Education, Science, and Technological Development of the Republic of Serbia for postdoctoral research. We are grateful to R Rurali (ICMAB-CSIC) for providing the structural model of the PbI<INF>2</INF> nanotube employed for the schematic representation of PbI<INF>2</INF>@MVWCNT. ; |
Approved |
Most recent IF: 13.942 |
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Call Number |
UA @ lucian @ c:irua:153169 |
Serial |
5127 |
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Author |
Feld, A.; Weimer, A.; Kornowski, A.; Winckelmans, N.; Merkl, J.-P.; Kloust, H.; Zierold, R.; Schmidtke, C.; Schotten, T.; Riedner, M.; Bals, S.; Weller, P.D., Horst |
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Title |
Chemistry of Shape-Controlled Iron Oxide Nanocrystal Formation |
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A1 Journal article |
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Year |
2018 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
13 |
Issue |
13 |
Pages |
152-162 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Herein we demonstrate that meticulous and in-depth analysis of the reaction mechanisms of nanoparticle formation is rewarded by full control of size, shape and crystal structure of superparamagnetic iron oxide nanocrystals during synthesis. Starting from two iron sources – iron(II)- and iron(III) carbonate -a strict separation of oleate formation from the generation of reactive pyrolysis products and concomitant nucleation of iron oxide nanoparticles was achieved. This protocol enabled us to analyze each step of nanoparticle formation independently in depth. Progress of the entire reaction was monitored via matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and gas chromatography (GC) gaining insight into the formation of various iron oleate species prior to nucleation. Interestingly, due to the intrinsic strongly reductive pyrolysis conditions of the oleate intermediates and redox process in early stages of the synthesis, pristine iron oxide nuclei were composed exclusively from wustite, irrespective of the oxidation state of the iron source. Controlling the reaction conditions provided a very broad range of size- and shape defined monodisperse iron oxide nanoparticles. Curiously, after nucleation star shaped nanocrystals were obtained, which underwent metamorphism towards cubic shaped particles. EELS tomography revealed ex post oxidation of the primary wustite nanocrystal providing a full 3D image of Fe2+ and Fe3+ distribution within. Overall, we developed a highly flexible synthesis, yielding multigram amounts of well-defined iron oxide nanocrystals of different sizes and morphologies. |
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Wos |
000456749900017 |
Publication Date |
2018-12-12 |
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ISSN |
1936-0851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
54 |
Open Access |
OpenAccess |
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Notes |
The authors gratefully acknowledge financial support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Projektnummer 192346071 – SFB 986 and the excellence cluster ‘The Hamburg Centre for Ultrafast Imaging – Structure, Dynamics and Control of Matter at the Atomic Scale’ (by grant EXC 1074) S.B. and N.W. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOMS) and from the Research Foundation Flanders (FWO, Belgium) through Project fundings G038116N. Dr. Volker Sauerland for his support in calibrating the MALDI-TOF spectra. Almut Bark for measuring XRD (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ecas_sara |
Approved |
Most recent IF: 13.942 |
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Call Number |
EMAT @ emat @c:irua:155716UA @ admin @ c:irua:155716 |
Serial |
5073 |
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Author |
Brodu, A.; Ballottin, M.V.; Buhot, J.; van Harten, E.J.; Dupont, D.; La Porta, A.; Prins, P.T.; Tessier, M.D.; Versteegh, M.A.M.; Zwiller, V.; Bals, S.; Hens, Z.; Rabouw, F.T.; Christianen, P.C.M.; de Donega, C.M.; Vanmaekelbergh, D. |
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Title |
Exciton Fine Structure and Lattice Dynamics in InP/ZnSe Core/Shell Quantum Dots |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
ACS Photonics |
Abbreviated Journal |
Acs Photonics |
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Volume |
5 |
Issue |
5 |
Pages |
3353-3362 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanocrystalline InP quantum dots (QDs) hold promise for heavy-metal-free optoelectronic applications due to their bright and size tunable emission in the visible range. Photochemical stability and high photoluminescence (PL) quantum yield are obtained by a diversity of epitaxial shells around the InP core. To understand and optimize the emission line shapes, the exciton fine structure of InP core/shell QD systems needs be investigated. Here, we study the exciton fine structure of InP/ZnSe core/shell QDs with core diameters ranging from 2.9 to 3.6 nm (PL peak from 2.3 to 1.95 eV at 4 K). PL decay measurements as a function of temperature in the 10 mK to 300 K range show that the lowest exciton fine structure state is a dark state, from which radiative recombination is assisted by coupling to confined acoustic phonons with energies ranging from 4 to 7 meV, depending on the core diameter. Circularly polarized fluorescence line-narrowing (FLN) spectroscopy at 4 K under high magnetic fields (up to 30 T) demonstrates that radiative recombination from the dark F = +/- 2 state involves acoustic and optical phonons, from both the InP core and the ZnSe shell. Our data indicate that the highest intensity FLN peak is an acoustic phonon replica rather than a zero-phonon line, implying that the energy separation observed between the F = +/- 1 state and the highest intensity peak in the FLN spectra (6 to 16 meV, depending on the InP core size) is larger than the splitting between the dark and bright fine structure exciton states. |
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Wos |
000442185900049 |
Publication Date |
2018-07-18 |
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ISSN |
2330-4022 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.756 |
Times cited |
40 |
Open Access |
OpenAccess |
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Notes |
; We acknowledge the support of the HFML-RU/FOM, member of the European Magnetic Field Laboratory (EMFL). D.V. and Z.H. acknowledge support by the European Commission via the Marie-Sklodowska Curie action Phonsi (H2020-MSCA-ITN-642656) and the Marie Sklodowska-Curie Action Compass (H2020 MSCA-RISE-691185). Z.H. acknowledges the Research Foundation Flanders (project 17006602) and Ghent University (GOA no. 01G01513). Z.H. and S.B. acknowledge SIM vzw (SBO-QDOCCO). F.T.R. acknowledges financial support from The Netherlands Organisation for Scientific Research NWO (Gravitation program Multiscale Catalytic Energy Conversion and VENI grant number 722.017.002). This work was also supported by the Dutch NWO-Physics Program DDC13, ERC Advanced Grant 692691 “First step”, and ERC Starting Grant 335078 “COLOURATOM”. ; ecas_sara |
Approved |
Most recent IF: 6.756 |
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Call Number |
UA @ lucian @ c:irua:153753UA @ admin @ c:irua:153753 |
Serial |
5100 |
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