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Verheijen M, Meier M, Ochoteco J, Gant T, Tong W, Yauk C, Caiment F. P20-03 R-ODAF: an omics data analysis framework for regulatory application. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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2
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Wen Q, Verheijen M, Wittens M, Engelborghs S, Bergdahl I, Kyrtopoulos S, de Kok T, Smeets H, Briedé J, Krauskopf J. LP-28 Lead-exposure associated miRNAs in humans and Alzheimer’s disease: Potential biomarkers of the disease and disease processes. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Phung N, Verheijen M, Todinova A, Datta K, Verhage M, Al-Ashouri A, Köbler H, Li X, Abate A, Albrecht S, Creatore M. Enhanced Self-Assembled Monolayer Surface Coverage by ALD NiO in p-i-n Perovskite Solar Cells. ACS Appl Mater Interfaces 2022; 14:2166-2176. [PMID: 34936322 PMCID: PMC8763377 DOI: 10.1021/acsami.1c15860] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Metal halide perovskites have attracted tremendous attention due to their excellent electronic properties. Recent advancements in device performance and stability of perovskite solar cells (PSCs) have been achieved with the application of self-assembled monolayers (SAMs), serving as stand-alone hole transport layers in the p-i-n architecture. Specifically, phosphonic acid SAMs, directly functionalizing indium-tin oxide (ITO), are presently adopted for highly efficient devices. Despite their successes, so far, little is known about the surface coverage of SAMs on ITO used in PSCs application, which can affect the device performance, as non-covered areas can result in shunting or low open-circuit voltage. In this study, we investigate the surface coverage of SAMs on ITO and observe that the SAM of MeO-2PACz ([2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid) inhomogeneously covers the ITO substrate. Instead, when adopting an intermediate layer of NiO between ITO and the SAM, the homogeneity, and hence the surface coverage of the SAM, improve. In this work, NiO is processed by plasma-assisted atomic layer deposition (ALD) with Ni(MeCp)2 as the precursor and O2 plasma as the co-reactant. Specifically, the presence of ALD NiO leads to a homogeneous distribution of SAM molecules on the metal oxide area, accompanied by a high shunt resistance in the devices with respect to those with SAM directly processed on ITO. At the same time, the SAM is key to the improvement of the open-circuit voltage of NiO + MeO-2PACz devices compared to those with NiO alone. Thus, the combination of NiO and SAM results in a narrower distribution of device performance reaching a more than 20% efficient champion device. The enhancement of SAM coverage in the presence of NiO is corroborated by several characterization techniques including advanced imaging by transmission electron microscopy (TEM), elemental composition quantification by Rutherford backscattering spectrometry (RBS), and conductive atomic force microscopy (c-AFM) mapping. We believe this finding will further promote the usage of phosphonic acid based SAM molecules in perovskite PV.
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Affiliation(s)
- Nga Phung
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - Marcel Verheijen
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - Anna Todinova
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - Kunal Datta
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - Michael Verhage
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - Amran Al-Ashouri
- Young
Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekulestraße 5, 12489 Berlin, Germany
| | - Hans Köbler
- Young
Investigator Group Active Materials and Interfaces for Stable Perovskite
Solar Cells, Helmholtz-Zentrum Berlin für
Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
| | - Xin Li
- Young
Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekulestraße 5, 12489 Berlin, Germany
| | - Antonio Abate
- Young
Investigator Group Active Materials and Interfaces for Stable Perovskite
Solar Cells, Helmholtz-Zentrum Berlin für
Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
- Department
of Chemical, Materials and Production Engineering, University of Naples Federico II, Piazzale Tecchio 80, 80125 Fuorigrotta, Italy
| | - Steve Albrecht
- Young
Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekulestraße 5, 12489 Berlin, Germany
- Faculty
of Electrical Engineering and Computer Science, Technical University Berlin, Marchstraße 23, 10587 Berlin, Germany
| | - Mariadriana Creatore
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
- Solliance, High Tech Campus 21, 5656 AE Eindhoven, The Netherlands
- Eindhoven
Institute of Renewable Energy Systems (EIRES), P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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4
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Ulu Okudur F, D'Haen J, Vranken T, De Sloovere D, Verheijen M, Karakulina OM, Abakumov AM, Hadermann J, Van Bael MK, Hardy A. Ti surface doping of LiNi0.5Mn1.5O4−δ positive electrodes for lithium ion batteries. RSC Adv 2018; 8:7287-7300. [PMID: 35540314 PMCID: PMC9078446 DOI: 10.1039/c7ra12932g] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/06/2018] [Indexed: 01/28/2023] Open
Abstract
The particle surface of LiNi0.5Mn1.5O4−δ (LNMO), a Li-ion battery cathode material, has been modified by Ti cation doping through a hydrolysis–condensation reaction followed by annealing in oxygen. The effect of different annealing temperatures (500–850 °C) on the Ti distribution and electrochemical performance of the surface modified LNMO was investigated. Ti cations diffuse from the preformed amorphous ‘TiOx’ layer into the LNMO surface during annealing at 500 °C. This results in a 2–4 nm thick Ti-rich spinel surface having lower Mn and Ni content compared to the core of the LNMO particles, which was observed with scanning transmission electron microscopy coupled with compositional EDX mapping. An increase in the annealing temperature promotes the formation of a Ti bulk doped LiNi(0.5−w)Mn(1.5+w)−tTitO4 phase and Ti-rich LiNi0.5Mn1.5−yTiyO4 segregates above 750 °C. Fourier-transform infrared spectrometry indicates increasing Ni–Mn ordering with annealing temperature, for both bare and surface modified LNMO. Ti surface modified LNMO annealed at 500 °C shows a superior cyclic stability, coulombic efficiency and rate performance compared to bare LNMO annealed at 500 °C when cycled at 3.4–4.9 V vs. Li/Li+. The improvements are probably due to suppressed Ni and Mn dissolution with Ti surface doping. LiNi0.5Mn1.5O4−δ surface is doped with Ti ion maintaining the spinel structure at 500 °C, higher annealing temperatures cause Ti diffusion from surface towards the core.![]()
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Affiliation(s)
- F. Ulu Okudur
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Partner in Energyville, Inorganic and Physical Chemistry
- Belgium
| | - J. D'Haen
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Materials Physics
- Belgium
| | - T. Vranken
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Partner in Energyville, Inorganic and Physical Chemistry
- Belgium
| | - D. De Sloovere
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Partner in Energyville, Inorganic and Physical Chemistry
- Belgium
| | - M. Verheijen
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Partner in Energyville, Inorganic and Physical Chemistry
- Belgium
| | | | - A. M. Abakumov
- EMAT
- University of Antwerp
- B-2020 Belgium
- Skoltech Center for Electrochemical Energy Storage
- Skolkovo Institute of Science and Technology
| | | | - M. K. Van Bael
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Partner in Energyville, Inorganic and Physical Chemistry
- Belgium
| | - A. Hardy
- UHasselt
- Institute for Materials Research (IMO-IMOMEC)
- Partner in Energyville, Inorganic and Physical Chemistry
- Belgium
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5
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Mann D, Voogt S, Keul H, Möller M, Verheijen M, Buskens P. Synthesis of Polystyrene⁻Polyphenylsiloxane Janus Particles through Colloidal Assembly with Unexpected High Selectivity: Mechanistic Insights and Their Application in the Design of Polystyrene Particles with Multiple Polyphenylsiloxane Patches. Polymers (Basel) 2017; 9:E475. [PMID: 30965778 PMCID: PMC6418681 DOI: 10.3390/polym9100475] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 09/21/2017] [Accepted: 09/26/2017] [Indexed: 01/26/2023] Open
Abstract
Janus particles are of great research interest because of their reduced symmetry, which provides them with unique physical and chemical properties. Such particles can be prepared from spherical structures through colloidal assembly. Whilst colloidal assembly has the potential to be a low cost and scalable process, it typically lacks selectivity. As a consequence, it results in a complex mixture of particles of different architectures, which is tedious to purify. Very recently, we reported the colloidal synthesis of Au semishells, making use of polystyrene⁻polyphenylsiloxane Janus particles as an intermediate product (Chem. Commun. 2017, 53, 3898⁻3901). Here, we demonstrate that these Janus particles are realized through colloidal assembly of spherical glucose-functionalized polystyrene particles and an emulsion of phenyltrimethoxysilane in aqueous ammonia, followed by interfacial polycondensation to form the polyphenylsiloxane patch. Both the polystyrene spheres and the emulsion of Ph-TMS in aqueous ammonia are stabilized by a surfmer-a reactive surfactant. The colloidal assembly reported in this manuscript proceeds with an unexpected high selectivity, which makes this process exceptionally interesting for the synthesis of Janus particles. Furthermore, we report insights into the details of the mechanism of formation of these Janus particles, and apply those to adapt the synthesis conditions to produce polystyrene particles selectively decorated with multiple polyphenylsiloxane patches, e.g., raspberry particles.
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Affiliation(s)
- Daniel Mann
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany.
- Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany.
| | - Stefanie Voogt
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany.
- Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany.
- Zuyd University of Applied Sciences, Nieuw Eyckholt 300, Postbus 550, 6400 AN Heerlen, The Netherlands.
| | - Helmut Keul
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany.
- Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany.
| | - Martin Möller
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany.
- Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany.
| | - Marcel Verheijen
- Philips Innovation Labs, High Tech Campus 11, 5656 AE Eindhoven, The Netherlands.
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - Pascal Buskens
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany.
- Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany.
- Zuyd University of Applied Sciences, Nieuw Eyckholt 300, Postbus 550, 6400 AN Heerlen, The Netherlands.
- The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP Eindhoven, The Netherlands.
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Mann D, Voogt S, van Zandvoort R, Keul H, Möller M, Verheijen M, Nascimento-Duplat D, Xu M, Urbach HP, Adam AJL, Buskens P. Protecting patches in colloidal synthesis of Au semishells. Chem Commun (Camb) 2017; 53:3898-3901. [PMID: 28322386 DOI: 10.1039/c7cc00689f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Protecting groups are commonly applied in multi-step molecular syntheses to protect one or multiple functional groups from reacting. After the reaction, they are removed from the molecule. In full analogy to this concept, we report the practical and scalable colloidal synthesis of Au semishells using polyphenylsiloxane protecting patches to prevent part of the surface of polystyrene nanoparticles from being covered with Au. After Au deposition, the patches are removed yielding Au semishells. We anticipate that this strategy can be extended to the synthesis of other types of non-centrosymmetric nanoparticles.
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Affiliation(s)
- Daniel Mann
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany and RWTH Aachen University, Institute for Technical and Macromolecular Chemistry, Worringerweg 2, 52074 Aachen, Germany
| | - Stefanie Voogt
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany and RWTH Aachen University, Institute for Technical and Macromolecular Chemistry, Worringerweg 2, 52074 Aachen, Germany and Zuyd University of Applied Sciences, Nieuw Eyckholt 300, Postbus 550, 6400 AN Heerlen, The Netherlands
| | - Ryan van Zandvoort
- The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP Eindhoven, The Netherlands.
| | - Helmut Keul
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany and RWTH Aachen University, Institute for Technical and Macromolecular Chemistry, Worringerweg 2, 52074 Aachen, Germany
| | - Martin Möller
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany and RWTH Aachen University, Institute for Technical and Macromolecular Chemistry, Worringerweg 2, 52074 Aachen, Germany
| | - Marcel Verheijen
- Philips Innovation Labs, High Tech Campus 11, 5656 AE Eindhoven, The Netherlands and Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Daniel Nascimento-Duplat
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Man Xu
- The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP Eindhoven, The Netherlands. and Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - H Paul Urbach
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Aurèle J L Adam
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Pascal Buskens
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany and RWTH Aachen University, Institute for Technical and Macromolecular Chemistry, Worringerweg 2, 52074 Aachen, Germany and Zuyd University of Applied Sciences, Nieuw Eyckholt 300, Postbus 550, 6400 AN Heerlen, The Netherlands and The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP Eindhoven, The Netherlands.
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7
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Mann D, Nascimento-Duplat D, Keul H, Möller M, Verheijen M, Xu M, Urbach HP, Adam AJL, Buskens P. The Influence of Particle Size Distribution and Shell Imperfections on the Plasmon Resonance of Au and Ag Nanoshells. Plasmonics 2016; 12:929-945. [PMID: 28539851 PMCID: PMC5420003 DOI: 10.1007/s11468-016-0345-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/22/2016] [Indexed: 05/02/2023]
Abstract
Au and Ag nanoshells are of interest for a wide range of applications. The plasmon resonance of such nanoshells is the property of interest and can be tuned in a broad spectral regime, ranging from the ultraviolet to the mid-infrared. To date, a large number of manuscripts have been published on the optics of such nanoshells. Few of these, however, address the effect of particle size distribution and metal shell imperfections on the plasmon resonance. Both are inherent to the chemical synthesis of metal nanoshells and therefore to a large extent unavoidable. It is of vital importance to understand their effect on the plasmon resonance, since this determines the scope and limitations of the technology and may have a direct impact on the application of such particles. Here, we elucidate the effect of particle size distribution and imperfections in the metal shell on the plasmon resonance of Au and Ag nanoshells. The size of the polystyrene core and the thickness of the Au and Ag shells are systematically varied to study their influence on the plasmon resonance, and the results are compared to values obtained through optical simulations using extended Mie theory and finite element method. Discrepancies between theory and practice are studied in detail and discussed extensively. Quantitative information on the minimum thickness of the metal shell, which is required to realize a satisfactory plasmon resonance of a metal nanoshell, is provided for Au and Ag.
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Affiliation(s)
- Daniel Mann
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany
| | - Daniel Nascimento-Duplat
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Helmut Keul
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany
| | - Martin Möller
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany
| | - Marcel Verheijen
- Philips Innovation Labs, High Tech Campus 11, 5656 AE Eindhoven, The Netherlands
- Department of Applied Physics, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Man Xu
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
- The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP Eindhoven, The Netherlands
| | - H Paul Urbach
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Aurèle J L Adam
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Pascal Buskens
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, 52056 Aachen, Germany
- The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP Eindhoven, The Netherlands
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8
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Krause A, Weber WM, Pohl D, Rellinghaus B, Verheijen M, Mikolajick T. Investigation of embedded perovskite nanoparticles for enhanced capacitor permittivities. ACS Appl Mater Interfaces 2014; 6:19737-19743. [PMID: 25330400 DOI: 10.1021/am504831q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Growth experiments show significant differences in the crystallization of ultrathin CaTiO3 layers on polycrystalline Pt surfaces. While the deposition of ultrathin layers below crystallization temperature inhibits the full layer crystallization, local epitaxial growth of CaTiO3 crystals on top of specific oriented Pt crystals occurs. The result is a formation of crystals embedded in an amorphous matrix. An epitaxial alignment of the cubic CaTiO3 ⟨111⟩ direction on top of the underlying Pt {111} surface has been observed. A reduced forming energy is attributed to an interplay of surface energies at the {111} interface of both materials and CaTiO3 nanocrystallites facets. The preferential texturing of CaTiO3 layers on top of Pt has been used in the preparation of ultrathin metal-insulator-metal capacitors with 5-30 nm oxide thickness. The effective CaTiO3 permittivity in the capacitor stack increases to 55 compared to capacitors with amorphous layers and a permittivity of 28. The isolated CaTiO3 crystals exhibit a passivation of the CaTiO3 grain surfaces by the surrounding amorphous matrix, which keeps the capacitor leakage current at ideally low values comparable for those of amorphous thin film capacitors.
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Affiliation(s)
- Andreas Krause
- NaMLab gGmbH , Noethnitzer Strasse 64, 01187 Dresden, Germany
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9
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Mann D, Chattopadhyay S, Pargen S, Verheijen M, Keul H, Buskens P, Möller M. Glucose-functionalized polystyrene particles designed for selective deposition of silver on the surface. RSC Adv 2014. [DOI: 10.1039/c4ra10941d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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10
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Assafrao AC, Wachters AJH, Verheijen M, Nugrowati AM, Pereira SF, Urbach HP, Armand MF, Olivier S. Direct measurement of the near-field super resolved focused spot in InSb. Opt Express 2012; 20:10426-10437. [PMID: 22535133 DOI: 10.1364/oe.20.010426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Under appropriate laser exposure, a thin film of InSb exhibits a sub-wavelength thermally modified area that can be used to focus light beyond the diffraction limit. This technique, called Super-Resolution Near-Field Structure, is a potential candidate for ultrahigh density optical data storage and many other high-resolution applications. We combined near field microscopy, confocal microscopy and time resolved pump-probe technique to directly measure the induced sub-diffraction limited spot in the near-field regime. The measured spot size was found to be dependent on the laser power and a decrease of 25% (100 nm) was observed. Experimental evidences that support a threshold-like simulation model to describe the effect are also provided. The experimental data are in excellent agreement with rigorous simulations obtained with a three dimensional Finite Element Method code.
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Affiliation(s)
- A C Assafrao
- Optics Research Group, Department of Imaging Science and Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
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11
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Kaiser M, Doytcheva M, Verheijen M, de Jonge N. In situ transmission electron microscopy observations of individually selected freestanding carbon nanotubes during field emission. Ultramicroscopy 2006; 106:902-8. [PMID: 16737778 DOI: 10.1016/j.ultramic.2006.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Revised: 03/20/2006] [Accepted: 04/04/2006] [Indexed: 10/24/2022]
Abstract
For the successful application of carbon nanotubes (CNTs) as electron sources in various applications it is important to understand the relation between the morphology of the CNT and its emission properties. A method was developed to study individual, freestanding and pre-selected CNTs with high-resolution transmission electron microscopy (TEM). The technique provided important parameters of the CNT, such as the number of carbon walls and the nature of its apex. The resolution with which the freestanding apices were imaged depended linearly on the ratio of the length and the radius. CNTs were also imaged in situ in the TEM while emitting electrons. It was found that the structure of a CNT was highly stable below a certain threshold emission current of typically 2 microA, while various structural changes occurred above the threshold, leading to either damaging or repair of the structure at the apex of the CNT.
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Affiliation(s)
- Monja Kaiser
- Philips Research Laboratories, High Tech Campus 11, 5656 AE Eindhoven, The Netherlands.
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12
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Wondergem H, Bakkers E, Balkenende R, Verheijen M. Twin formation in InP nanowires epitaxially grown on germanium and silicon. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305083650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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13
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Bakkers EPAM, van Dam JA, De Franceschi S, Kouwenhoven LP, Kaiser M, Verheijen M, Wondergem H, van der Sluis P. Epitaxial growth of InP nanowires on germanium. Nat Mater 2004; 3:769-773. [PMID: 15475961 DOI: 10.1038/nmat1235] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Accepted: 08/16/2004] [Indexed: 05/24/2023]
Abstract
The growth of III-V semiconductors on silicon would allow the integration of their superior (opto-)electronic properties with silicon technology. But fundamental issues such as lattice and thermal expansion mismatch and the formation of antiphase domains have prevented the epitaxial integration of III-V with group IV semiconductors. Here we demonstrate the principle of epitaxial growth of III-V nanowires on a group IV substrate. We have grown InP nanowires on germanium substrates by a vapour-liquid-solid method. Although the crystal lattice mismatch is large (3.7%), the as-grown wires are monocrystalline and virtually free of dislocations. X-ray diffraction unambiguously demonstrates the heteroepitaxial growth of the nanowires. In addition, we show that a low-resistance electrical contact can be obtained between the wires and the substrate.
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Affiliation(s)
- Erik P A M Bakkers
- Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven, The Netherlands.
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Seah MP, Spencer SJ, Bensebaa F, Vickridge I, Danzebrink H, Krumrey M, Gross T, Oesterle W, Wendler E, Rheinländer B, Azuma Y, Kojima I, Suzuki N, Suzuki M, Tanuma S, Moon DW, Lee HJ, Cho HM, Chen HY, Wee ATS, Osipowicz T, Pan JS, Jordaan WA, Hauert R, Klotz U, van der Marel C, Verheijen M, Tamminga Y, Jeynes C, Bailey P, Biswas S, Falke U, Nguyen NV, Chandler-Horowitz D, Ehrstein JR, Muller D, Dura JA. Critical review of the current status of thickness measurements for ultrathin SiO2 on Si Part V: Results of a CCQM pilot study. SURF INTERFACE ANAL 2004. [DOI: 10.1002/sia.1909] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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