Fig. 2.

Transition metal dichalcogenide (TMD)-nanoscrolls (NSs) from self-scrolling chemical vapor deposition (CVD)-based TMD monolayer flakes. a Optical image of CVD-grown MoS₂ monolayer flakes on a SiO₂/Si substrate (the purple area represents the substrate, the green area represents the MoS₂ monolayers; scale bar, 500 μm). b Optical image of MoS₂-NSs on a SiO₂/Si substrate (scale bar, 100 μm). c–e The fabrication process of a MoS₂-NS array (scanning electron microscopy—SEM image shown, scale bars, 50 μm). c Large-area MoS₂ monolayer film patterned into ribbons by focused ion beam (FIB) etching (the dark region represents MoS₂ film, the bright area is bare substrate). d Long MoS₂-NSs made from the controllable scrolling of the patterned MoS₂ film in c. (The white parallel lines are MoS₂-NSs, and the dark area represents the substrate). e A 12 × 6 array of MoS₂-NSs fabricated via a second FIB etching of the long MoS₂-NSs in d. f–i SEM images of typical TMD-NSs on SiO₂/Si substrates: MoS₂-NSs (f),WS₂-NSs (g), MoSe₂-NSs (h), and WSe₂-NSs (i). (Scale bars, 5 μm in f, i and 10 μm in g, h). j–m TEM images of typical TMD-NSs: MoS₂-NSs (j),WS₂-NSs (k), MoSe₂-NSs (l), and WSe₂-NSs (m). (Scale bars, 20 nm). Inset: High-magnification images of sidewalls of TMD-NSs (scale bars, 2 nm)