Nanostructuring on WSe2 with the atomic force microscope by a potential controlled electrochemical reaction

We present a method for the controlled fabrication of stable nanostructures under ambient conditions. The surfaces under consideration, WSe2, are imaged by an atomic force microscope. By applying a voltage between the tip and the sample, we can control an etching process at the surface: different voltage thresholds for the creation and the growth of structures of one monolayer (Se-W-Se) depth are observed. Our measurements on p-doped WSe strongly support an electrochemical corrosion reaction in a physisorbed water him. This method allows the in situ preparation and characterization of individual nanometer-sized structures on WSe2 and other metal dichalcogenides. (C) 1996 American Institute of Physics.