Figure 1.

The device fabrication on WSe₂ basal plane. a) A schematic diagram of the fabrication process and b) a realistic optical image of WSe₂ device. c) The AFM height image of the protected PMMA layer, where the window is exposed by EBL only on the WSe₂ basal plane. The inset shows the low pass filtered atomic pattern acquired from the center region by lateral force microscopy. d) The electrical performance of WSe₂ device in the air and an electrolyte. The electrolyte is 0.5 mol L⁻¹ H₂SO₄ solution.