An Experimental Investigation on Enhanced Electron Field Emission from CeO2 Nanoparticles Decorated Graphene Sheets

In this study, we describe an experimental investigation on the electron field emission characteristics of ceria (CeO2) nanoparticles decorated graphene sheets. Graphene was synthesized from graphite oxide (GO) by hydrogen exfoliation technique. Decoration of CeO2 nanoparticles was done by chemical reduction technique. The synthesized material was characterized by X-ray diffraction (XRD), field electron scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and confocal Raman spectroscopy. The field emitter was fabricated on flexible carbon cloth and emission characteristics were studied using an indigenously fabricated setup. The field emission current density-electric field (J-E) plot for CeO2-HEG gives a low turn on field of 0.76 V/mu m at a current density of 10 mu A/cm(2), which is better than HEG based emitter (1.25 V/mu m). A threshold field of 0.93 V/mu m and 1.56 V/mu m at a current density of 0.2 mA/cm(2) are observed for CeO2-HEG and HEG based emitters respectively. The emission characteristics follows Fowler-Nordheim (FN) tunneling theory and the field enhancement factor (beta) was calculated from the fitted FN plots which were 5734 and 4870 for CeO2-HEG and HEG respectively. Compared to pure HEG based field emitter, CeO2-HEG based emitter showed better field enhancement which suggests CeO2-HEG can be considered as potential material for flexible field emission display technology.