STRUCTURAL DEFORMATION OF TUNGSTEN DISELENIDE NANOSTRUCTURES INDUCED BY OZONE OXIDATION AND INVESTIGATION OF ELECTRONIC PROPERTIES CHANGE.

Tungsten diselenide (WSe2) is one of the promising transition metal dichalcogenides (TMDs) for nanoelectronics and optoelectronics. To enhance and tune the electronic performance of TMDs, chemical functionalization via covalent and van der Waals approaches has been suggested. In the present report, the electric and structural transition of WSe₂ oxidized by exposure to O3 is investigated using scanning tunneling microscopy. It is demonstrated that the exposure of WSe2/high-ordered pyrolytic graphite sample to O₃ induces the formation of molecular adsorbates on the surface, which enables to increase in the density of states near the valence band edge, resulting from electric structural modification of domain boundaries via exposure of atomic O. According to the work function extracted by Kelvin probe force microscopy, monolayer WSe2 with the O₃ exposure results in a gradual increase in work function as the exposure to O₃. Therefore, the present report demonstrates the potential pathway for the chemical functionalization of TMDs to enhance the electric performance of TMDs devices. [ABSTRACT FROM AUTHOR]