Extended Data Fig. 2: The large-scale optical image.
From: Realization of 2D metals at the ångström thickness limit
a, The optical microscopy images of Bi over a ~1 mm2 area produced under ~140 MPa. Those areas marked with white dashed lines are the monolayer regions; while those areas marked with brown dashed lines are the bilayer MoS2 regions without metal inside. b, Zoom-in optical images taken from the red rectangular area of (a). c, AFM images of monolayer Bi. The height line profile indicates the thickness of ~0.64 nm.
