11 results on '"Ludovic Tortech"'
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2. In-Situ Energy Dispersive X-ray Reflectivity Applied to Polyoxometalate Films: An Approach to Morphology and Interface Stability Issues in Organic Photovoltaics
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Amanda Generosi, Marco Guaragno, Qirong Zhu, Anna Proust, Nicholas T. Barrett, Ludovic Tortech, and Barbara Paci
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time resolved EDXR ,in-situ X-ray characterization ,polyoxymetalate functional materials ,thin films structure and morphology ,organic photovoltaics ,Mathematics ,QA1-939 - Abstract
Organic solar cells, characterized by a symmetrical regular layered structure, are very promising systems for developing green, low cost, and flexible solar energy conversion devices. Despite the efficiencies being appealing (over 17%), the technological transfer is still limited by the low durability. Several processes, in bulk and at interface, are responsible. The quick downgrading of the performance is due to a combination of physical and chemical degradations. These phenomena induce instability and a drop of performance in working conditions. Close monitoring of these processes is mandatory to understand the degradation pathways upon device operation. Here, an unconventional approach based on Energy Dispersive X-ray Reflectivity (ED-XRR) performed in-situ is used to address the role of Wells–Dawson polyoxometalate (K6-P2W18O62, hereafter K6-P2W18) as hole transporting layer in organic photovoltaics. The results demonstrate that K6-P2W18 thin films, showing ideal bulk and interface properties and superior optical/morphological stability upon prolonged illumination, are attractive candidates for the interface of durable OPV devices.
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- 2020
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3. Conductivity via Thermally Induced Gap States in a Polyoxometalate Thin Layer
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Cindy L. Rountree, Amanda Generosi, Barbara Paci, Anna Proust, Qirong Zhu, Claire Mathieu, Nicholas Barrett, Guillaume Izzet, Pierre Gouzerh, Séverine Renaudineau, Ludovic Tortech, Xihui Liang, Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Consiglio Nazionale delle Ricerche [Roma] (CNR), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), DIM NanoK, région Ile de France, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)
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Materials science ,Photoemission spectroscopy ,02 engineering and technology ,Conductivity ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Polyoxometalate Thin Layer ,Physical and Theoretical Chemistry ,Electrical conductor ,Deposition (law) ,business.industry ,Thermally Induced Gap- States ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Thermal conduction ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,General Energy ,Polyoxometalate ,Optoelectronics ,0210 nano-technology ,business ,Layer (electronics) - Abstract
International audience; We report a study of alpha-[P2W18O62]6-, Wells-Dawson polyoxometalate layers deposited on ITO coated glass substrates. A variety of techniques has been used including atomic force microscopy for surface topography characterization, current mapping and current-voltage characteristics, X-ray photoemission spectroscopy for chemical analysis, UV-visible photoemission spectroscopy for determination of band line-ups and energy dispersive X-ray reflectivity for determination of layer thicknesses and scattering length densities. The conditions of film deposition and subsequent thermal annealing strongly affect the film characteristics. In particular, we show that nanostriped films a few tens of nm thick can be obtained in a reproducible manner and that such structuring is accompanied by the appearance of gap-states and by a switch from an insulating to a conductive state. Current-voltage characteristics demonstrate that highly ordered films of K 6 [P 2 W 18 O 62 ] allow electron flow only from ITO to [P2W18O62]6-, thus showing a rectifying effect. Finally, we integrate the POM layer 2 into an organic photovoltaic device and show the conduction through it thanks to favorable band alignment between ITO, the gap states and the active photovoltaic layers.
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- 2019
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4. Electrical properties of iron corrosion layers formed in anoxic environments at the nanometer scale
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Delphine Neff, Florence Mercier-Bion, Hélène Lotz, Ludovic Tortech, Jiaying Li, Philippe Dillmann, Laboratoire Archéomatériaux et Prévision de l'Altération (LAPA - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), IRAMAT - Laboratoire Métallurgies et Cultures (IRAMAT - LMC), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Edifices PolyMétalliques (E-POM), Institut Parisien de Chimie Moléculaire (IPCM), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,General Chemical Engineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Corrosion ,Metal ,chemistry.chemical_compound ,Iron corrosion ,General Materials Science ,FESEM ,Electrical conductor ,Magnetite ,C-AFM ,[CHIM.MATE]Chemical Sciences/Material chemistry ,General Chemistry ,Conductive atomic force microscopy ,021001 nanoscience & nanotechnology ,Anoxic waters ,0104 chemical sciences ,chemistry ,Chemical engineering ,visual_art ,Electrical properties ,visual_art.visual_art_medium ,Archaeological artefact ,Carbonate ,Nanometre ,µRaman ,0210 nano-technology - Abstract
International audience; The electrical properties of the corrosion layers on archaeological iron artefacts were determined by Conductive Atomic Force Microscopy. Different corrosion products were studied: Fe$^{II}$ carbonates, magnetite entrapped in the carbonate, and iron sulfides. The results indicate that the ferrous carbonate matrix is insulating, and that magnetite and iron sulfides have a conductive character, although these phases are not systematically connected to the metal. This suggests that electrons produced by the anodic dissolution of metal would be conducted to the external part of the corrosion product layer through a three-dimensional network of connected magnetite strips passing through the ferrous carbonate matrix.
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- 2018
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5. Enhancement of photovoltaic efficiency by insertion of a polyoxometalate layer at the anode of an organic solar cell
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Denis Fichou, Guillaume Izzet, Anna Proust, Nicholas Barrett, Julien E. Rault, Q. Zhu, M. Alaaeddine, Ludovic Tortech, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
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Condensed Matter - Materials Science ,Materials science ,Organic solar cell ,Photovoltaic system ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Physics - Applied Physics ,Applied Physics (physics.app-ph) ,[CHIM.MATE]Chemical Sciences/Material chemistry ,7. Clean energy ,Polymer solar cell ,Anode ,Indium tin oxide ,Inorganic Chemistry ,X-ray photoelectron spectroscopy ,Chemical engineering ,Polyoxometalate ,Layer (electronics) - Abstract
In this article the Wells-Dawson polyoxometalate K6[P2W18O62] is grown as an interfacial layer between indium tin oxide and bulk heterojunction of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The structure of the POM layers depends on the thickness and shows a highly anisotropic surface organization. The films have been characterized by atomic force microscopy and X-ray photoelectron spectroscopy (XPS) to gain insight into their macroscopic organization and better understand their electronic properties. Then, they were put at the anodic interface of a P3HT:PCBM organic solar cell and characterized on an optical bench. The photovoltaic efficiency is discussed in terms of the benefit of the polyoxometalate at the anodic interface of an organic photovoltaic cell., Comment: 7 pages, 6 figures
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- 2014
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6. Self-assembled monolayers of semifluorinated thiols on electrochemically modified polycrystalline nickel surfaces
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Serge Geribaldi, Frédéric Guittard, Zineb Mekhalif, Joseph Delhalle, and Ludovic Tortech
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chemistry.chemical_classification ,Chemistry ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,Self-assembled monolayer ,Surfaces and Interfaces ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Contact angle ,Nickel ,X-ray photoelectron spectroscopy ,Transition metal ,Monolayer ,Polymer chemistry ,Materials Chemistry ,Thiol ,Cyclic voltammetry - Abstract
Electrochemically pretreated polycrystalline nickel substrates modified with ethanolic solutions (10 − 2 and 10 − 1 M) of four semi-fluorinated thiols with R F –R H –SH structures have been evaluated by X-ray photoelectron spectroscopy, contact angles and cyclic voltammetry measurements. Our results show that it is possible to graft highly fluorinated alkanethiols on nickel surfaces, the quality of the self assembled monolayers depending on the concentration of the dipping solutions, the dipping time as well as the length of the perfluorinated carbon chains and those of the hydrocarbon connector between the perfluorinated fragment and the thiol function.
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- 2005
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7. Synthesis and photovoltaic performances in solution-processed BHJs of oligothiophene-substituted organocobalt complexes [(η⁴-C₄(nT)₄)Co(η⁵-C₅H₅)]
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Guillaume H V, Bertrand, Ludovic, Tortech, Vincent, Gandon, Corinne, Aubert, and Denis, Fichou
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We describe an efficient synthetic route toward novel organocobalt complexes [(η(4)-C4(nT)4)Co(η(5)-C5H5)] with n = 1, 2, 3 thiophene rings. Solution-processed bulk heterojunctions solar cells based on CpCoCb(3T)4:PCBM blends achieve power conversion efficiencies of up to 2.1%.
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- 2014
8. Growth and magnetic behavior in hybrid organic–inorganic Ferrite/Alq3/Co heterostructures
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Frédéric Ott, Marie-Joseph Guittet, Jean-Baptiste Moussy, Florentin Rengnez, Denis Fichou, Sylvia Matzen, and Ludovic Tortech
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Spintronics ,business.industry ,Chemistry ,Mineralogy ,Heterojunction ,General Chemistry ,Surface finish ,Organic inorganic ,Electrode ,Materials Chemistry ,Optoelectronics ,Ferrite (magnet) ,Nanometre ,business ,Decoupling (electronics) - Abstract
We report the growth and magnetic properties of AFe2O4/Alq3/Co heterostructures (AFe, Co) containing a continuous Alq3 thin layer with a low roughness, down to a few nanometers, and we demonstrate the magnetic decoupling between AFe2O4 and Co electrodes showing the interest of these systems for spintronics devices.
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- 2009
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9. An Improved Protocol forthe Synthesis of [(η4-C4R4)Co(η5-C5H5)] Complexes.
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Guillaume Bertrand, Ludovic Tortech, Denis Fichou, Max Malacria, Corinne Aubert, and Vincent Gandon
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COMPLEX compounds synthesis , *METAL complexes , *ORGANOCOBALT compounds , *ALKYNES , *CHEMICAL reactions , *MICROWAVES , *CYCLOPENTADIENE , *REACTIVITY (Chemistry) - Abstract
The reaction of bulky alkynes C2R2with (η5-C5H5)Co(CO)(dimethylfumarate) undermicrowave irradiation provides complexes of the type [(η4-C4R4)Co(η5-C5H5)] in good to excellent yields. This protocol representsa significant improvement over those reported previously. In particular,the formation of insertion products such as cyclopentadienones orcyclohexadienes can be avoided. In addition, because of the exceptionalstability of (η5-C5H5)Co(CO)(dimethylfumarate), the reactions can be carried out in crude solvents. Theeasy access to [(η4-C4R4)Co(η5-C5H5)] complexes stimulated a studyof their reactivity, notably under cross-coupling conditions. [ABSTRACT FROM AUTHOR]
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- 2012
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10. Growth and magnetic behavior in hybrid organic–inorganic Ferrite/Alq3/Co heterostructures.
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Jean-Baptiste Moussy, Ludovic Tortech, Florentin Rengnez, Sylvia Matzen, Frédéric Ott, Marie-Joseph Guittet, and Denis Fichou
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We report the growth and magnetic properties of AFe2O4/Alq3/Co heterostructures (AFe, Co) containing a continuous Alq3thin layer with a low roughness, down to a few nanometers, and we demonstrate the magnetic decoupling between AFe2O4and Co electrodes showing the interest of these systems for spintronics devices. [ABSTRACT FROM AUTHOR]
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- 2009
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11. Physical chemistry of the TiN/Hf 0.5 Zr 0.5 O 2 interface
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Uwe Schroeder, Thomas Mikolajick, Nicholas Barrett, Ludovic Tortech, Christophe Lubin, A. Pancotti, W. Hamouda, Claudia Richter, Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN UMR 3685), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), NaMLab gGmbH, Laboratoire Innovation en Chimie des Surfaces et NanoSciences (LICSEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ANR-11-EQPX-0005,ATTOLAB,Plateforme pour la dynamique attoseconde(2011), European Project: 780302,EC | H2020 | RIA,3eFERRO(2018), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
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010302 applied physics ,[PHYS]Physics [physics] ,Materials science ,Annealing (metallurgy) ,Schottky barrier ,Doping ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Conductive atomic force microscopy ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Photoemission electron microscopy ,X-ray photoelectron spectroscopy ,chemistry ,0103 physical sciences ,Physical chemistry ,[CHIM]Chemical Sciences ,Thin film ,0210 nano-technology ,Tin ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience; Ferroelectric hafnia-based thin films are promising candidates for emerging high-density embedded nonvolatile memory technologies, thanks to their compatibility with silicon technology and the possibility of 3D integration. The electrode–ferroelectric interface and the crystallization annealing temperature may play an important role in such memory cells. The top interface in a TiN/Hf0.5Zr0.5O2/TiN metal–ferroelectric–metal stack annealed at different temperatures was investigated with X-ray photoelectron spectroscopy. The uniformity and continuity of the 2 nm TiN top electrode was verified by photoemission electron microscopy and conductive atomic force microscopy. Partial oxidation of the electrode at the interface is identified. Hf is reduced near the top interface due to oxygen scavenging by the top electrode. The oxygen vacancy (VO) profile showed a maximum at the top interface (0.71%) and a sharp decrease into the film, giving rise to an internal field. Annealing at higher temperatures did not affect the VO concentration at the top interface but causes the generation of additional VO in the film, leading to a decrease of the Schottky Barrier Height for electrons. The interface chemistry and n-type film doping are believed to be at the origin of several phenomena, including wake-up, imprint, and fatigue. Our results give insights into the physical chemistry of the top interface with the accumulation of defective charges acting as electronic traps, causing a local imprint effect. This may explain the wake-up behavior as well and also can be a possible reason of the weaker endurance observed in these systems when increasing the annealing temperature
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