Theoretical Perspective of Atomic Resolution Secondary Electron Imaging
Long Cheng, Lihao Yang, Rongguang Zeng, Ming Yi, Bo Da, Zejun Ding
Abstract
Atomic resolution secondary electron imaging (ARSEI) has become an alternative tool for material characterization; however, its application potential is still underestimated due to insufficient understanding of the imaging mechanism. In this work, a robust quantum trajectory Monte Carlo method is developed to theoretically investigate the physical processes of ARSEI and thereby establish a new imaging mechanism. The new mechanism suggests that ARSEI can even identify the atoms of the same element in different atomic layers near the surface with a depth difference <2 Å. Thus, ARSEI can be expected to greatly promote the development of material characterization. For example, it may help to directly observe the AA, AB, and BA stacking in few-layer two-dimensional materials and to determine in which layer of a multilayer material an atom is adsorbed.