Electron emission from a solvothermally synthesized ZnS-RGO nanocomposite field emitter

A simple solvothermal method was used to synthesize reduced graphene oxide (RGO) nanocomposite which was found to be decorated with zinc sulphide (ZnS) microspheres. The field emission studies were carried out in UHV environment (1×10
^-8
mbar) to evaluate the stability of electron emission and the current density levels. The results of XRD and RAMAN spectra confirmed the formation of hexagonal phase ZnS and the reduction of GO to RGO. The SEM and TEM images showed that ZnS microspheres were deposited on RGO sheets. The turn-on field value, defined at an emission current density of 1 μA/cm
²
, is found to be 2.32 V/μm for the ZnS-RGO emitter. Furthermore, the ZnS-RGO emitter delivers a maximum emission current density of 1050 μA/cm
²
at an applied field of ~ 4.1V/μm. The results obtained herein propose the ZnS-RGO nanocomposite emitter to be a potential electron source for practical applications in vacuum nanoelectronic devices.