Depth, relaxation and temperature dependence of defect complexes in scanning transmission electron microscopy (1906.01471v1)

Abstract: We propose a new analysis approach for scanning transmission electron microscopy (STEM) based on the Voronoi-cell integration method to determine the three-dimensional position of the InZn and VZn defect complex in ZnO. Using state of the art simulation software and hardware, we propose using a method of calculating Michelson Contrast on simulated images to determine the optimal acceptance angles to use in an experimental setting. The effect of defect position, DFT-relaxation and cooling the sample to liquid nitrogen temperatures is investigated. DFT-relaxation is shown to be of consequence to accurately determine the three-dimensional position of the defect. Relaxation is also shown to have a significant impact on neighbouring columns at liquid nitrogen temperatures.