SURFACE MODIFICATION OF MOSE2 IN SOLUTION USING A COMBINED TECHNIQUE OF SCANNING-TUNNELING-MICROSCOPY INDENTATION WITH ELECTROCHEMICAL ETCHING

Surface modification of MoSe2 has been accomplished in an electrochemi cal environment by a combined technique of scanning tunneling microsco py (STM) indentation with the following etching reaction. The artifici al holes (defects), amde by STPYI indentation, could successfully serv e as sites that initiated the electrochemical etching reaction that re sulted in growth of the holes. The etching progressed in a highly anis otropic way, mainly occurring toward directions within the basal plane of the MoSe2, and predominantly leaving the step edges with equilater al triangular shapes. The etched holes had depths of a few van der Waa ls layers of the MoSe2, irrespective of the depths of the artificially made initial holes. The present technique could provide favorable opp ortunities not only for nanometer scale lithography in solution but al so for fundamental studies on the mechanism of the etching processes a t layered transition metal dichalcogenide materials.