Abstract:
Reduced graphene oxide (RGO) has in recent studies proven to be a suitable contender for electron field emission owing to high field enhancement due to high aspect ratio and atomically thin edges. Graphene thin films for field emission have been prepared by using numerous solution-based deposition techniques such as membrane filtration, dip coating, spray-coating, spin coating etc. Among these methods, Electrophoretic deposition (EPD) stands advantageous due to factors such as easy setup and scalability, high adhesion, thickness control and high uniformity. In most of these studies the graphene is reduced before deposition, reduction is mainly controlled chemically by hydrazine hydrate or thermally. In-situ film deposition and simultaneous anodic reduction of graphene oxide (GO) platelets using EPD has already been reported. Our study focuses on deposition of GO on various metallic substrates and investigation of the extent of reduction of GO (prepared using improved hummers method) under varying EPD parameters such as time, voltage of deposition, electrode gap, electrode material and their respective field emission behaviour. Attempts were also made to improve the field emission response of the RGO films by further controlled reduction of these films. Field emission current as high as 2.7 mA/cm2 and lowest turn field of 1.5 V/μm were achieved.
