In TEM and high-voltage STEM, one of the big advantage that high resolution and sensitivity can provide us is the ability to analyze the interfaces and defects in more detail and the distribution of point defects (vacancies and impurities) around these structures. However, point defects are mobile, and thus the defect and interface structures are less stable than the bulk material.

Furthermore, in many cases, the major issue is the lack of image contrast at the interfaces for materials with similar compositions or Z-number employed in the thin films and thus, we cannot clearly differentiate some particular multilayer structures.