Identifying different stacking sequences in few-layer CVD-grown Mo S2 by low-energy atomic-resolution scanning transmission electron microscopy

Atomically thin MoS2 grown by chemical vapor deposition (CVD) is a promising candidate for next-generation electronics due to inherent CVD scalability and controllability. However, it is well known that the stacking sequence in few-layer MoS2 can significantly impact electrical and optical properties. Herein we report different intrinsic stacking sequences in CVD-grown few-layer MoS2 obtained by atomic-resolution annular-dark-field imaging in an aberration-corrected scanning transmission electron microscope operated at 50 keV. Trilayer MoS2 displays a new stacking sequence distinct from the commonly observed 2H and 3R phases of MoS2. Density functional theory is used to examine the stability of different stacking sequences, and the findings are consistent with our experimental observations.