Scanning Moiré Fringe Method: A Superior Approach to Perceive Defects, Interfaces, and Distortion in 2D Materials.

Scanning moiré fringe (SMF) is a widely utilized technique for the precise measurement of the strain field in semiconductor transistors and heterointerfaces. With the growing challenges of traditional chip scaling, two-dimensional (2D) materials turn out to be ideal candidates for incorporation into semiconductor devices. Therefore, a method to efficiently locate defects and grain boundaries in 2D materials is highly essential. Here, we present a demonstration of using the SMF method to locate the domain boundaries at the nearly coherent interfaces with sub-angstrom spatial resolution under submicron fields of views. The strain field of small angle grain boundary and lateral heterojunction are instantaneously found and precisely determined by a quick SMF method without any atomic resolution images.