Extended Data Fig. 10: vdW squeezing experiments under different pressures.
From: Realization of 2D metals at the ångström thickness limit
The optical microscope images of the as-produced Bi under 50 MPa (a), 80 MPa (b), 100 MPa (c), 130 MPa (d), 140 MPa (e). The scale bars are 20 μm. When the applied pressure is small, i.e., 50 MPa and 80 MPa, all Bi samples produced are thick and no monolayer Bi can be found. When the applied pressure is increased to a moderate value, i.e., 100 MPa and 120 MPa, mono-, bi-, tri-, and few-layer Bi samples can be observed simultaneously, and the probability that monolayer Bi occurs increases with increasing the applied pressure. When the applied pressure is high, i.e., 140 MPa, Bi monolayers larger than 100 μm can be obtained.
