Fermi level shifting of tungsten disulfide (WS2) nanosheets by swift heavy ion irradiation.

This work presents the evolution of change in the structural and optical properties of Tungsten Disulfide nanosheets irradiated by swift heavy ion (Ag+9, 120MeV). For this work tungsten disulfide nanosheet was prepared using liquid phase sonication procedure in a mixer of ethanol-water solution. The optical and surface properties of as-prepared nanosheets were characterized through UV-Visible, FESEM, and TEM. Raman spectroscopy and scanning Kelvin probe microscopy were further performed to observe the effect of electrical change due to swift heavy ion irradiation. A blue shift of the Raman modes indicates an external strain has been induced in the system. Study of scanning kelvin probe microscopy reveals that the defect generated by ion beam induced a modification in surface electronic properties of WS2. [ABSTRACT FROM AUTHOR]