Figure 3. Characterization of the crystal structure of synthesized MoS₂ monolayer and bilayer films.

(a), High angle annular dark field (HAADF) image of typical MoS₂ monolayer film. Upper inset is the corresponding FFT pattern, which is not indexed for visual convenience (an indexed version is given in Fig. S12a). Lower inset shows the folded edges of MoS₂ monolayer and bilayer films. The lattice constant and important crystalline directions are given as shown. (b) and (c), HAADF of MoS₂ monolayer and bilayer films. The image of the bilayer film (c) is filtered and the original version is given in Fig. S12b. The insets show modeled crystal structures of MoS₂ monolayer and bilayer films with blue and yellow dots corresponding to Mo and S atoms, respectively. The sulfur atom in the inset of (c) is not given for visual convenience.