Library Item
Superior Field Emission Properties of Layered WS2-RGO Nanocomposites
Description:
We report here the field emission studies of a layered WS2-RGO composite at the base pressure of ~1×10^-8 mbar. The turn on field required to draw a field emission current density of 1 microA/cm^2 is found to be 3.5, 2.3 and 2 V/microm for WS2, RGO and the WS2-RGO composite respectively. The enhanced field emission behavior observed for the WS2-RGO nanocomposite is attributed to a high field enhancement factor of 2978, which is associated with the surface protrusions of the single-to-few layer thick sheets of the nanocomposite. The highest current density of ~800 microA/cm^2 is drawn at an applied field of 4.1 V/microm from a few layers of the WS2-RGO nanocomposite. Furthermore, first-principles density functional calculations suggest that the enhanced field emission may also be due to an overlap of the electronic structures of WS2 and RGO, where graphene-like states are dumped in the region of the WS2 fundamental gap.
