Efficient field emission from graphene nanosheets decorated with platinum nanoparticles

Abstract

Graphene and its derivatives are expected to be efficient field emitters due to their unique geometry and electrical properties. In this work we have decorated Graphene nanosheets with noble metal nanoparticles specifically Platinum by simple chemical route which produces high density of protrusions. The assynthesized Graphene nanosheets were characterized using XRD and TEM. The values of turn-on and threshold fields, required to draw an emission current density ~ 1 and ~10 μA/cm ² , are found to be ~ 1.55 and ~1.70 V/μm, for anode-cathode separation of ~ 2 mm. Interestingly, very high emission current density of ~ 496.5 μA/cm ² has been drawn from the emitter at relatively lower applied electric field of ~ 3.1 V/μm. The observed field emission characteristics can be attributed to the enhancement of the applied electric field at these local protrusions, thus increasing the number of emission sites. The emission current stability studied at the preset value of ~1 μA over the period of more than 3 hrs is found to be good, characterized with fewer fluctuations. The observed results indicate that field emission behaviour of Graphene can be improved by decorating it with Pt nanoparticles.