Fabricating and Examining of Langmuir Films of Reduced Graphene Oxide

The effect the transfer pressure has on structural, optical, and electrophysical properties of Langmuir-Blodgett (LB) films of reduced graphene oxide (rGO) is studied. Investigation of physicochemical properties of rGO monolayers on the subphase surface shows that the rGO monolayer on the subphase surface predominantly exists in the liquid state. Increased surface pressure in the film makes rGO particles lie closer to and contact one another, followed by the overlapping and crumpling of some film sheets. Electron microscope studies show that as monolayers are transferred onto solid substrates, rGO forms uniform island-type films with clearly discernible clusters whose density grows along with surface pressure. The synthesized rGO films are highly transparent (87-96%) in the visible spectral region. The LB films transferred onto solid substrates at a lower surface pressure exhibit the best electrophysical and electroconductive properties. The reported findings can be used in developing technology for synthesizing transparent nanosized films from reduced graphene oxide and its derivatives for use in molecular electronics and photovoltaics.