Differential Phase Contrast Imaging on 2D Materials / Maja Groll ; 1. Gutachter: Prof. Dr. Jörg K. N. Lindner, 2. Gutachter: Prof. Dr. Uwe Gerstmann. Paderborn, 2025
Inhalt
- Acknowledgements
- Abstract
- Introduction
- Fundamentals
- Transmission Electron Microscopy
- Scanning Transmission Electron Microscopy
- Wave-optical Picture in STEM
- Phase Object Approximation in STEM
- Differential Phase Contrast
- Multislice STEM Image Simulation
- 2D Transition Metal Dichalcogenides
- Specimen Damage under Electron Irradiation
- Experimental Details
- Microscope Properties & Layout
- Segmented Detector and Signal Acquisition
- Image Post-Processing
- Basic Image Corrections
- Denoising and Correction of Specimen Drift
- Quantitative Analysis of DPC Images
- Specimen Preparation
- Electric Field and Charge Density Distributions in a WSe2 Monolayer
- Quantitative STEM-DPC Investigations of a WSe2 Monolayer
- Influence of Lens Aberrations on quantitative DPC Imaging of 2D Materials
- Influence of the Detector Configuration and Detector Rotation on DPC Images of 2D Materials
- Influence of the Detector Configuration on DPC Images of 2D Materials
- Influence of Detector Rotation on DPC Images of 2D Materials
- Investigation of the Influence of single and multiple Atoms on quantitative DPC Imaging
- Influence of the Atomic Number
- Influence of the Distance of Atoms
- Influence of the Number of Atoms
- Influence of the Beam Propagation
- Investigation of the Atomic Potential and the Influence of the Crystal Structure
- Influence of Contamination on DPC Images
- Electric Field and Charge Density Distributions in a MoS2 Monolayer
- Different Stacking Configurations of WSe2 Bilayers
- Influence of different Stacking Configurations of WSe2 Bilayers
- Moire Homostructure of a WSe2 Bilayer
- Defects in a WSe2 Monolayer
- Single Selenium Vacancy in a WSe2 Monolayer
- Comparison of different Point Defects in a WSe2 Monolayer
- Comparison with DFT Calculations
- Conclusion and Outlook
- Appendix
- Contrast Transfer Function of segmented Detectors
- Drift Correction of high-resolution STEM Images
- Influence of the Detector Rotation
- Influence of the Number of Atoms
- Influence of the non-rigid Registration Algorithm on STEM-DPC Images of a contaminated WSe2 Monolayer
- Visible Light Microscopy Image of 2D-MoS2 Flakes
- STEM-DPC investigations of a Selenium Single Vacancy in a WSe2 Monolayer
- Multislice Image Simulations of Point Defects in a WSe2 Monolayer
- Drift-corrected HAADF Images of three different Point Defects in a WSe2 Monolayer
- Determination of the Number of Layers by HAADF Imaging
- Simulation Parameters
- Multislice Image Simulations
- DFT Calculations of the Electron Charge Distribution for a Selenium Double Vacancy
- Details on Image Post-Processing of experimental Data
- Multislice Image Simulation of different Stacking Configurations
- Multislice image simulation of different Combinations of Lens Aberrations for a WSe2 Monolayer
- References
- Declaration of Plagiarism
- List of Publications