Fig. 2: Mechanical characterisations of mono- and few-layer pressurised TMD nano-domes.
From: Variant Plateau’s law in atomically thin transition metal dichalcogenide dome networks
a–c Atomic force microscope (AFM) images of a 1 L (a), 2 L (b) and 3 L dome (c). The measured centre dome height (hm) to radius (R) ratio (hm/R) for 1–3 L domes are 0.18, 0.17, and 0.16, respectively. d–f Stiffness mapping images measured for the 1–3 L domes shown in a–c. g Force-indentation curves (dots) measured at the centre of domes with different layer numbers (1–3 L). The simulated force-indentation curves (solid lines) from finite element analysis (FEA) match very well with the measured ones. The inset shows the experimental set up for data acquisition: an AFM tip was used for the mechanical nano-indentation of domes. h Measured stiffness as a function of dome radius (solid dots), for 1–3 L domes. Simulated results (lines) by FEA match well with experimental observations. i Extracted two-dimensional modulus (E2D) of WS2 as a function of layer number. The extracted E2D values are 244.0 ± 35.7, 429.5 ± 37.7 and 520.4 ± 49.2 N/m for 1–3 L WS2 domes, respectively. The error bars represent statistical variation from 20 domes for each group with different layer number.
