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Author Arteaga Cardona, F.; Jain, N.; Popescu, R.; Busko, D.; Madirov, E.; Arús, B.A.; Gerthsen, D.; De Backer, A.; Bals, S.; Bruns, O.T.; Chmyrov, A.; Van Aert, S.; Richards, B.S.; Hudry, D.
Title Preventing cation intermixing enables 50% quantum yield in sub-15 nm short-wave infrared-emitting rare-earth based core-shell nanocrystals Type A1 Journal Article
Year (down) 2023 Publication Nature communications Abbreviated Journal Nat Commun
Volume 14 Issue 1 Pages 4462
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Short-wave infrared (SWIR) fluorescence could become the new gold standard in optical imaging for biomedical applications due to important advantages such as lack of autofluorescence, weak photon absorption by blood and tissues, and reduced photon scattering coefficient. Therefore, contrary to the visible and NIR regions, tissues become translucent in the SWIR region. Nevertheless, the lack of bright and biocompatible probes is a key challenge that must be overcome to unlock the full potential of SWIR fluorescence. Although rare-earth-based core-shell nanocrystals appeared as promising SWIR probes, they suffer from limited photoluminescence quantum yield (PLQY). The lack of control over the atomic scale organization of such complex materials is one of the main barriers limiting their optical performance. Here, the growth of either homogeneous (α-NaYF<sub>4</sub>) or heterogeneous (CaF<sub>2</sub>) shell domains on optically-active α-NaYF<sub>4</sub>:Yb:Er (with and without Ce<sup>3+</sup>co-doping) core nanocrystals is reported. The atomic scale organization can be controlled by preventing cation intermixing only in heterogeneous core-shell nanocrystals with a dramatic impact on the PLQY. The latter reached 50% at 60 mW/cm<sup>2</sup>; one of the highest reported PLQY values for sub-15 nm nanocrystals. The most efficient nanocrystals were utilized for in vivo imaging above 1450 nm.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001037058500022 Publication Date 2023-07-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited 1 Open Access OpenAccess
Notes D.H. would like to thank Dominique Ectors (Bruker AXS GmbH, Karlsruhe, Germany) for assistance and discussion on the PXRD data and TOPAS evaluations. The authors would like to acknowledge the financial support provided by the Helmholtz Association via: i) the Professorial Recruitment Initiative Funding (B.S.R.); ii) the Research Field Energy – Program Materials and Technologies for the Energy Transition – Topic 1 Photovoltaics (F.A.C., D.B., E.M., B.S.R., D.H.). This project received funding from the European Union’s Horizon 2020 innovation programme under grant agreement 823717. This work was supported by the European Research Council (grant 770887-PICOMETRICS to S.V.A. and Grant 815128-REALNANO to S.B.). The authors acknowledge financial support from the ResearchFoundation Flanders (FWO, Belgium) through project fundings (G.0346.21 N to S.V.A. and S.B.) and a postdoctoral grant (A.D.B.). The authors (B.A.A., O.T.B. and A.C.) acknowledge funding from the Helmholtz Zentrum München, the DFG-Emmy Noether program (BR 5355/2-1) and from the CZI Deep Tissue Imaging (DTI-0000000248). The authors (O.T.B. and D.H.) would like to thank the Helmholtz Imaging (ZT-I-PF-4-038-BENIGN). Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number EMAT @ emat @c:irua:198158 Serial 8808
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Author Hudry, D.; De Backer, A.; Popescu, R.; Busko, D.; Howard, I.A.; Bals, S.; Zhang, Y.; Pedrazo‐Tardajos, A.; Van Aert, S.; Gerthsen, D.; Altantzis, T.; Richards, B.S.
Title Interface Pattern Engineering in Core‐Shell Upconverting Nanocrystals: Shedding Light on Critical Parameters and Consequences for the Photoluminescence Properties Type A1 Journal article
Year (down) 2021 Publication Small Abbreviated Journal Small
Volume Issue Pages 2104441
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract Advances in controlling energy migration pathways in core-shell lanthanide (Ln)-based hetero-nanocrystals (HNCs) have relied heavily on assumptions about how optically active centers are distributed within individual HNCs. In this article, it is demonstrated that different types of interface patterns can be formed depending on shell growth conditions. Such interface patterns are not only identified but also characterized with spatial resolution ranging from the nanometer- to the atomic-scale. In the most favorable cases, atomic-scale resolved maps of individual particles are obtained. It is also demonstrated that, for the same type of core-shell architecture, the interface pattern can be engineered with thicknesses of just 1 nm up to several tens of nanometers. Total alloying between the core and shell domains is also possible when using ultra-small particles as seeds. Finally, with different types of interface patterns (same architecture and chemical composition of the core and shell domains) it is possible to modify the output color (yellow, red, and green-yellow) or change (improvement or degradation) the absolute upconversion quantum yield. The results presented in this article introduce an important paradigm shift and pave the way toward the emergence of a new generation of core-shell Ln-based HNCs with better control over their atomic-scale organization.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000710758000001 Publication Date 2021-10-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1613-6810 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.643 Times cited 17 Open Access OpenAccess
Notes The authors would like to acknowledge the financial support provided by the Helmholtz Recruitment Initiative Fellowship (B.S.R.) and the Helmholtz Association's Research Field Energy (Materials and Technologies for the Energy Transition program, Topic 1 Photovoltaics and Wind Energy). The authors would like to thank the Karlsruhe Nano Micro Facility (KNMF) for STEM access. 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 PICOMETRICS to S.V.A. and Grant agreement no. 815128 REALNANO to S.B.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects no. G.0502.18N, G.0267.18N, and a postdoctoral grant to A.D.B. T.A. acknowledges funding from the University of Antwerp Research fund (BOF). This project had received funding (EUSMI proposal #E181100205) from the European Union's Horizon 2020 Research and Innovation Programme under Grant agreement no 731019 (EUSMI). D.H. would like to thank “CGFigures” for helpful tutorials on 3D graphics with Blender.; sygmaSB Approved Most recent IF: 8.643
Call Number EMAT @ emat @c:irua:183285 Serial 6817
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Author Bach, D.; Schneider, R.; Gerthsen, D.; Verbeeck, J.; Sigle, W.
Title EELS of niobium and stoichiometric niobium-oxide phases: part 1: plasmon and Near-edges fine structure Type A1 Journal article
Year (down) 2009 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 15 Issue 6 Pages 505-523
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A comprehensive electron energy-loss spectroscopy study of niobium (Nb) and stable Nb-oxide phases (NbO, NbO2, Nb2O5) was carried out. In this work (Part I), the plasmons and energy-loss near-edge structures (ELNES) of all relevant Nb edges (Nb-N2,3, Nb-M4,5, Nb-M2,3, Nb-M1, and Nb-L2,3) up to energy losses of about 2600 eV and the O-K edge are analyzed with respect to achieving characteristic fingerprints of Nb in different formal oxidation states (0 for metallic Nb, +2 for NbO, +4 for NbO2, and +5 for Nb2O5). Chemical shifts of the Nb-N2,3, Nb-M4,5, Nb-M2,3, and Nb-L2,3 edges are extracted from the spectra that amount to about 4 eV as the oxidation state increases from 0 for Nb to +5 for Nb2O5. Four different microscopes, including a 200 keV ZEISS Libra with monochromator, were used. The corresponding wide range of experimental parameters with respect to the primary electron energy, convergence, and collection semi-angles as well as energy resolution allows an assessment of the influence of the experimental setup on the ELNES of the different edges. Finally, the intensity of the Nb-L2,3 white-line edges is correlated with niobium 4d-state occupancy in the different reference materials.
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Corporate Author Thesis
Publisher Place of Publication Cambridge, Mass. Editor
Language Wos 000272433200005 Publication Date 2009-10-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276;1435-8115; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 55 Open Access
Notes Approved Most recent IF: 1.891; 2009 IF: 3.035
Call Number UA @ lucian @ c:irua:80320UA @ admin @ c:irua:80320 Serial 790
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Author Bach, D.; Störmer, H.; Schneider, R.; Gerthsen, D.; Verbeeck, J.
Title EELS investigations of different niobium oxide phases Type A1 Journal article
Year (down) 2006 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal
Volume 12 Issue 5 Pages 416-423
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Electron energy loss spectra in conjunction with near-edge fine structures of purely stoichiometric niobium monoxide (NbO) and niobium pentoxide (Nb2O5) reference materials were recorded. The structures of the niobium oxide reference materials were checked by selected area electron diffraction to ensure a proper assignment of the fine structures. NbO and Nb2O5 show clearly different energy loss near-edge fine structures of the Nb-M-4,M-5 and -M-2,M-3 edges and of the O-K edge, reflecting the specific local environments of the ionized atoms. To distinguish the two oxides in a quantitative manner, the intensities under the Nb-M-4,M-5 as well as Nb-M-2,M-3 edges and the O-K edge were measured and their ratios calculated. k-factors were also derived from these measurements.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge, Mass. Editor
Language Wos 000241181400007 Publication Date 2006-09-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1431-9276;1435-8115; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.891 Times cited 50 Open Access
Notes Approved Most recent IF: 1.891; 2006 IF: 2.108
Call Number UA @ lucian @ c:irua:60979UA @ admin @ c:irua:60979 Serial 789
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Author Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kruse, P.; Gerthsen, D.
Title Ab initio computation of the mean inner Coulomb potential of wurtzite-type semiconductors and gold Type A1 Journal article
Year (down) 2006 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 88 Issue 23 Pages Artn 232108
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000238914500031 Publication Date 2006-06-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 8 Open Access
Notes Approved Most recent IF: 3.411; 2006 IF: 3.977
Call Number UA @ lucian @ c:irua:60581 Serial 33
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Author Kruse, P.; Schowalter, M.; Lamoen, D.; Rosenauer, A.; Gerthsen, D.
Title Determination of the mean inner potential in III-V semiconductors, Si and Ge by density functional theory and electron holography Type A1 Journal article
Year (down) 2006 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 106 Issue 2 Pages 105-113
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000234535900005 Publication Date 2005-07-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.843 Times cited 50 Open Access
Notes Approved Most recent IF: 2.843; 2006 IF: 1.706
Call Number UA @ lucian @ c:irua:56143 Serial 678
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Author Müller, E.; Kruse, P.; Gerthsen, D.; Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kling, R.; Waag, A.
Title Measurement of the mean inner potential of ZnO nanorods by transmission electron holography Type A1 Journal article
Year (down) 2005 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 86 Issue 15 Pages
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000228901600121 Publication Date 2005-04-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 5 Open Access
Notes Approved Most recent IF: 3.411; 2005 IF: 4.127
Call Number UA @ lucian @ c:irua:54917 Serial 1963
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Author Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kruse, P.; Gerthsen, D.
Title Ab initio computation of the mean inner Coulomb potential of technological important semiconductors Type A1 Journal article
Year (down) 2005 Publication Abbreviated Journal
Volume 1007 Issue Pages 233-236
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0930-8989 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:72915 Serial 32
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Author Müller, E.; Kruse, P.; Gerthsen, D.; Schowalter, M.; Rosenauer, A.; Lamoen, D.; Kling, R.
Title Measurement of the mean inner potential of ZnO nanorods by transmission electron holography Type A1 Journal article
Year (down) 2005 Publication Microscopy of Semiconducting Materials Abbreviated Journal
Volume 107 Issue Pages 303-306
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title SPRINGER PROCEEDINGS IN PHYSICS Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0930-8989 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:72914 Serial 1962
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Author Schowalter, M.; Lamoen, D.; Kruse, P.; Gerthsen, D.; Rosenauer, A.
Title First-principles calculations of the mean inner Coulomb potential for sphalerite type II.VI semiconductors Type A1 Journal article
Year (down) 2004 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 85 Issue 21 Pages 4938-4940
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000225300600037 Publication Date 2004-11-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 16 Open Access
Notes Approved Most recent IF: 3.411; 2004 IF: 4.308
Call Number UA @ lucian @ c:irua:49657 Serial 1203
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Author Rosenauer, A.; Gerthsen, D.; Van Aert, S.; van Dyck, D.; den Dekker, A.J.
Title Present state of the composition evaluation of ternary semiconductor nanostructures by lattice fringe analysis Type A1 Journal article
Year (down) 2003 Publication Institute of physics conference series Abbreviated Journal
Volume Issue 180 Pages 19-22
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Semiconductor heterostructures are used for the fabrication of optoelectronic devices. Performance of such devices is governed by their chemical morphology. The composition distribution of quantum wells and dots is influenced by kinetic growth processes which are not understood completely at present. To obtain more information about these effects, methods for composition determination with a spatial resolution at a near atomic scale are necessary. In this paper we focus on the present state of the composition evaluation by the lattice fringe analysis (CELFA) technique and explain the basic ideas, optimum imaging conditions, precision and accuracy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0-7503-0979-2 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:95118 Serial 2710
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