Fig. 3: Optical images of WSe2 flakes with different contact metals integrated and peeled-off.
From: Wafer-scale and universal van der Waals metal semiconductor contact
a–f The upper panels show the optical images of different metals integrated on top of WSe2 flake, including Ag (a), Al (b), Cr (c), Cu (d), Co (e), Pd (f). In the meantime, the corresponding optical image after peeling-off electrodes are also demonstrated as the lower panels, where the white dash lines are used to highlight the outlines of electrode position. The underlying WSe2 nanosheets sustain their original shapes without observable cracks or wrinkles, indicating the weak vdW interaction between different metals with 2D materials. The scale bar is 40 μm.
