A5001144778- Advanced Materials Characterization Techniques
- Metal and Thin Film Mechanics
- Microstructure and mechanical properties
- Advanced materials and composites
- Diamond and Carbon-based Materials Research
- Aluminum Alloy Microstructure Properties
- Chalcogenide Semiconductor Thin Films
- Aluminum Alloys Composites Properties
- Quantum Dots Synthesis And Properties
- Semiconductor materials and interfaces
- nanoparticles nucleation surface interactions
- Metallic Glasses and Amorphous Alloys
- solar cell performance optimization
- High Entropy Alloys Studies
- Metallurgical and Alloy Processes
- Force Microscopy Techniques and Applications
- High Temperature Alloys and Creep
- High-Temperature Coating Behaviors
- Intermetallics and Advanced Alloy Properties
- Corrosion Behavior and Inhibition
- Hydrogen embrittlement and corrosion behaviors in metals
- Advanced Semiconductor Detectors and Materials
- Surface and Thin Film Phenomena
- Dental materials and restorations
- Magnesium Alloys: Properties and Applications
Chalmers University of Technology
2018-2023
Saarland University
2013-2020
Steinbeis Foundation
2017
Max-Planck-Institut für Nachhaltige Materialien
2015
Max Planck Society
2015
In this study, dual phase CuCo composites with a total immiscibility in the solid state and very different initial strength are deformed by severe plastic deformation. Nanocrystalline supersaturated solutions reached all independent of composition. The deformation mechanical mixing process is studied thoroughly combining scanning electron microscopy, transmission three-dimensional atom probe tomography nanoindentation. indentation hardness Cu Co its evolution as function applied strain...
Silver alloying of Cu(In,Ga)Se2 absorbers for thin film photovoltaics offers improvements in open-circuit voltage, especially when combined with optimal alkali-treatments and certain Ga concentrations. The relationship between alkali distribution the absorber Ag is investigated here, combining experimental theoretical studies. Atom probe tomography analysis implemented to quantify local composition grain interiors at boundaries. Na concentration bulk increases up ∼60 ppm [Ag]/([Ag] + [Cu]) =...
As-produced Cr-coated Optimized ZIRLO™ cladding material fabricated with the cold-spray (CS) deposition process is studied. Cross-sectional electron microscopy, nano-hardness profiling, transmission Kikuchi diffraction, and atom probe tomography (APT) were performed to investigate nature of CS Cr-coating/Optimized interface, microstructure coating, effects on Zr-substrate microstructure. The former surface was found have a highly deformed nano-crystalline microstructure, formation which...
This contribution studies the potential of an RbF postdeposition treatment (RbF‐PDT) wide‐gap (Ag,Cu)(In,Ga)Se 2 (ACIGS) absorbers to improve corresponding solar cell performance. While a higher open‐circuit voltage ( V OC ) and short‐circuit current density are achieved, lower fill factor (FF) is observed for most devices subjected RbF‐PDT. However, drop in FF can be avoided some close‐stoichiometric samples, leading maximum efficiencies beyond 16% (without antireflection coating) at...
A Cu-Co composite material is chosen as a model system to study structural evolution and phase formations during severe plastic deformation. The evolving microstructures function of the applied strain were characterized at micro-, nano-, atomic scale-levels by combining scanning electron microscopy transmission including energy-filtered energy-loss spectroscopy. amount intermixing between two phases different strains was examined scale using atom probe tomography complimentary method. It...
The influence of the microstructure on thermal behavior cathodic arc deposited TiAlN coatings was studied as a function isothermal annealing. Two compositionally similar but structurally different were compared, Ti0·34Al0·66N0.96 coating with fine-grain structure consisting mixture cubic (c) and hexagonal (h) phases, Ti0·40Al0·60N0.94 coarse-grain phase. By in situ wide-angle synchrotron x-ray scattering, spinodal decomposition confirmed both coatings. increased amount internal interfaces...
Thin films generally exhibit unusual kinetics leading to chemical reactions far from equilibrium conditions. Binary metallic multilayer thin with miscible elements show some similar behaviors respect interdiffusion and phase formation mechanisms. Interfacial density, lattice defects, internal stresses, layer morphologies deposition conditions strongly control the mass transport between individual layers. In present work, Ag/Al are used as a simple model system, in which effects of sputtering...
The cubic (Ti1−xAlx)Ny (TiAlN) phase with a nanolamella structure, synthesized via low pressure chemical vapour deposition (LPCVD), has been widely used in wear-resistant coatings during the latest years. structured TiAlN contain periodic and epitaxially grown Ti-rich [denoted as Ti(Al)N] Al-rich Al(Ti)N] lamellae. However, compositions of these nano-structures have not fully revealed. In this study, microstructure coating was studied using scanning transmission electron microscopy (SEM...
We report on crossing the 20% efficiency line for thin-film solar modules. The of our cadmium-free Cu(In,Ga)(S,Se) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (CIGSSe) mid-sized modules (30 × 30 cm <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) based cost-efficient AVANCIS stacked elemental layer – rapid thermal processing absorber process has evolved in last two years reaching 19.6%, 19.8% and recently we have achieved an...
Purpose To decrease wear and friction, zinc dialkyldithiophosphate (ZDDP) has been used in engine oil for several decades, but the mechanism of tribofilm formation is still unclear. The purpose this study to characterize chemical details by using high-resolution approaching. Design/methodology/approach An ISO VG 100 mineral mixed with ZDDP was sliding tests on cylindrical roller bearings. Tribofilm observed after 2 h test. X-ray photoelectron spectroscopy (XPS) atom probe tomography (APT)...
Abstract Surface sulfurization of Cu(In,Ga)Se 2 (CIGSe) absorbers is a commonly applied technique to improve the conversion efficiency corresponding solar cells, via increasing bandgap towards heterojunction. However, resulting device performance understood be highly dependent on thermodynamic stability chalcogenide structure at upper region absorber. The present investigation provides high-resolution chemical analysis, using energy dispersive X-ray spectrometry and laser-pulsed atom probe...
In this study, commercial Al–12Si and Al-12Si-xCe (x = 0.5, 1, 2, 4, 8 12 wt.% Ce) alloys were synthesized the effect of cerium (Ce) on microstructure thermal mechanical properties was systematically investigated. The coefficient expansion decreased from 25.9 × 10-6 K-1 to 24.3 (50-493 °C) with increasing addition Ce in alloys. XRD analyses revealed that α-Al, Si, CuZn5 present all caused formation Al9FeSi3, Al0.85CeSi1.15 AlCeSi2. chemical composition investigated energy dispersive...