Fig. 2: Cleavage feasibility of non-van der Waals InGaS₃.

a 100X optical micrograph of a typical nanosheet on Si/SiO₂ substrate. b AFM topographical scan over the region marked by dashed rectangle in panel (a). Height profile is taken along the dashed line in the map, showing the thickness equivalent to 5 L (8.71 ± 0.38 nm). c Same as in panel (b), but for thinner atomic sheets, with a thickness equivalent to 3 L (5.53 ± 0.32 nm) and 4 L (7.3 ± 0.34 nm). d Same as in panel (c), but for a magnified region marked by the dashed rectangle in panel (c) showing atomic strips with thicknesses equivalent to 1 L (1.74 ± 0.24 nm) and 2 L (1.74 + 1.86 ± 0.28 nm). e 100X optical micrograph of a typical nanosheet on a quartz substrate. White dot marks the Raman spectra collection point (145 ± 4 nm). f Raman spectra of the nanosheet presented in panel (e) at room (green line) and liquid nitrogen (red line) temperatures. Vertical bars label evaluated Raman-active modes (see Supplementary Table 3 for details). Insets: Schematic representation of lattice vibration directions of the corresponding Raman-active modes.