0000000000399812

AUTHOR

Nadine Witkowski

showing 6 related works from this author

Growth mode and self-organization of LuPc2on Si(001)-2×1vicinal surfaces: An optical investigation

2012

We report an investigation of the initial growth and of the self-organization of lutetium biphthalocyanine LuPc2 on Si(001)-2 x 1 vicinal surfaces. Using surface-sensitive optical spectroscopies, namely, surface-difference-reflectance spectroscopy (SDRS) and reflectance-anisotropy spectroscopy (RAS), together with local-probe microscopies, we are able to propose a scenario for the growth mode up to about 20 nm. We demonstrate that the growth mode initially proceeds through the formation of a wetting layer, followed by the formation of clusters whose sizes increase while keeping a constant shape in which the molecules are inclined. Moreover, the LuPc2 molecules are self-organized along the s…

Materials scienceMode (statistics)chemistry.chemical_element02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesMolecular physicsLutetium0104 chemical sciencesElectronic Optical and Magnetic MaterialschemistryMolecule0210 nano-technologyConstant (mathematics)SpectroscopyNormalVicinalWetting layerPhysical Review B
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High Tolerance of Double-Decker Phthalocyanine Towards Molecular Oxygen

2018

[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci][PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]
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Grafting, self-organization and reactivity of double-decker rare-earth phthalocyanine

2019

Unveiling the interplay of semiconducting organic molecules with their environment, such as inorganic materials or atmospheric gas, is the first step to designing hybrid devices with tailored optical, electronic or magnetic properties. The present article focuses on a double-decker lutetium phthalocyanine known as an intrinsic semiconducting molecule, holding a Lu ion in its center, sandwiched between two phthalocyanine rings. Carrying out experimental investigations by means of electron spectroscopies, X-ray diffraction and scanning probe microscopies together with advanced ab initio computations, allows us to unveil how this molecule interacts with weakly or highly reactive surfaces. Our…

Rare earthSTM02 engineering and technology010402 general chemistryPhotochemistryDFT01 natural sciencesOrganic moleculesNEXAFSchemistry.chemical_compoundX-ray photoelectron spectroscopyXPSReactivity (chemistry)LuPc2ChemistryGLXDGeneral ChemistryCondensed Matter Physics021001 nanoscience & nanotechnologyGraftingXANES0104 chemical sciencesPhthalocyanine0210 nano-technologyDen kondenserade materiens fysikDouble deckerJournal of Porphyrins and Phthalocyanines
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New Quadratic Self-Assembly of Double-Decker Phthalocyanine on Gold(111) Surface : From Macroscopic to Microscopic Scale

2018

Unveiling the self-organization mechanism of semiconducting organic molecules onto metallic surfaces is the first step to design hybrid devices in which the self-assembling is exploited to tailor magnetic properties. In this study, double-decker rare-earth phthalocyanines, namely, lutetium phthalocyanine (LuPc2), are deposited on Au(111) gold surface forming large-scale self-assemblies. Global and local experimental techniques, namely, grazing incidence X-ray diffraction and scanning tunneling microscopy, supplemented by density functional theory calculations with van der Waals corrections, give insight into the molecular structural arrangement of the thin film and the self organization at …

Surface (mathematics)Materials science02 engineering and technology01 natural sciencesPhysical ChemistryMicroscopic scaleOrganic moleculesMetalchemistry.chemical_compoundQuadratic equation0103 physical sciencesPhysical and Theoretical Chemistry010306 general physicsComputingMilieux_MISCELLANEOUSFysikalisk kemi021001 nanoscience & nanotechnologyCondensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsGeneral EnergychemistryChemical physicsvisual_art[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]visual_art.visual_art_mediumPhthalocyanineSelf-assembly0210 nano-technologyDouble deckerDen kondenserade materiens fysik
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High Tolerance of Double-Decker Phthalocyanine toward Molecular Oxygen

2018

Because organic electronics suffer from degradation-inducing oxidation processes, oxygen-tolerant organic molecules could solve this issue and be integrated to improve the stability of devices during operation. In this work, we investigate how lutetium double-decker phthalocyanine (LuPc2) reacts toward molecular oxygen and we report microscopic details of its interaction with LuPc2 film by combining X-ray photoemission spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and density functional theory. Surprisingly, LuPc2 molecules are found to weakly physisorb below 120 K and appear rather inert to molecular oxygen at more elevated temperatures. We are able to draw a micros…

Organic electronicsMaterials science010405 organic chemistryPhotoemission spectroscopychemistry.chemical_elementCondensed Matter Physics010402 general chemistryPhotochemistry01 natural sciencesOxygen0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialschemistry.chemical_compoundGeneral EnergychemistryPhthalocyanineMoleculeDensity functional theoryPhysical and Theoretical ChemistryAbsorption (chemistry)SpectroscopyDen kondenserade materiens fysikThe Journal of Physical Chemistry C
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When the Grafting of Double Decker Phthalocyanines on Si(100)-2 × 1 Partly Affects the Molecular Electronic Structure

2016

International audience; A combined X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density functional theory (DFT) study has been performed to characterize the adsorbate interaction of lutetium biphthalocyanine (LuPc2) molecules on the Si(100)-2 × 1 surface. Large molecule–substrate adsorption energies are computed and are found to compete with the molecule–molecule interactions of the double decker molecules. A particularly good matching between STM images and computed ones confirms the deformation of the molecule upon the absorption process. The comparison between DFT calculations and XP spectra reveals that the electronic distribution in the two plateaus …

lutetium bi-phthalocyanineSiliconXASAtom and Molecular Physics and OpticsSTMAnalytical chemistrychemistry.chemical_element02 engineering and technology010402 general chemistryDFT[ CHIM ] Chemical Sciences01 natural sciencesSi(100)law.inventionAdsorptionX-ray photoelectron spectroscopyscanning tunneling microscopelawbasis-setXPS[CHIM]Chemical SciencessurfaceMoleculePhysical and Theoretical ChemistryBasis setmetal-free phthalocyaninefield-effect transistorsPhthalocyaninebis-phthalocyanine021001 nanoscience & nanotechnology0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialstotal-energy calculationsGeneral EnergyElectronic Structurechemistrysi(001)Chemical physicsthin-filmsaugmented-wave methodAtom- och molekylfysik och optikDensity functional theoryScanning tunneling microscopeAbsorption (chemistry)0210 nano-technologyThe Journal of Physical Chemistry C
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