Cross-Sectional Observations of Layer Structures and Stacking Faults in Natural and Synthesized Molybdenum Disulfide Crystals by High-Resolution Transmission Electron Microscopy

Cross sections of the (0001) layers in natural (molybdenite) and synthesized molybdenum disulfide crystals have been observed by high-resolution transmission electron microscopy. The image simulation for hexagonal and rhombohedral MoS2 crystals which are perfect and contain various types of stacking faults shows that the Mo and S columns along the incident electron beam can be distinguished in the [2110] images and hence the stacking sequence of Mo and S layers can be determined. The layer structures and the formation mechanisms of the stacking faults which have been found in natural and synthesized molybdenum disulfide flakes are presented.