Simultaneous silicon oxide growth and electrophoretic deposition of graphene oxide.

During electrophoretic deposition of graphene oxide (GO) sheets on silicon substrates, not only deposition but also simultaneous anodic oxidation of the silicon substrate takes place, leading to a three-layered material. SEM images reveal the presence of GO sheets on the silicon substrate, and this is also confirmed by XPS, albeit that the carbon portion increases with increasing emission angle, hinting at a thin carbon layer. With increasing applied potential and increasing conductivity of the GO solution the carbon signal decreases, while the overall thickness of the added layer formed on top of the silicon substrate increases. Through XPS spectra in which the Si2p peaks shifted under those conditions to 103 - 104 eV we were able to conclude that significant amounts of oxygen are present, indicative of formation of an oxide layer. This leads us to conclude that GO can be deposited using electrophoretic deposition, but that at the same time silicon is oxidized, which may overshadow effects previously assigned to GO deposition.