Low Surface Roughness Graphene Oxide Film Reduced with Aluminum Film Deposited by Magnetron Sputtering

Graphene film has wide applications in optoelectronic and photovoltaic devices. A novel and facile method was reported for the reduction of graphene oxide (GO) film by electron transfer and nascent hydrogen produced between aluminum (Al) film deposited by magnetron sputtering and hydrochloric acid (HCl) solution for only 5 min, significantly shorter than by other chemical reduction methods. The thickness of Al film was controlled utilizing a metal detection sensor. The effect of the thickness of Al film and the concentration of HCl solution during the reduction was explored. The optimal thickness of Al film was obtained by UV-Vis spectroscopy and electrical conductivity measurement of reduced GO film. Atomic force microscope images could show the continuous film clearly, which resulted from the overlap of GO flakes, the film had a relatively flat surface morphology, and the surface roughness reduced from 7.68 to 3.13 nm after the Al reduction. The film sheet resistance can be obviously reduced, and it reached 9.38 kΩ/sq with a high transmittance of 80% (at 550 nm). The mechanism of the GO film reduction by electron transfer and nascent hydrogen during the procedure was also proposed and analyzed.