| dc.description.abstract | Recently, graphene has attracted a great number of attentions due to its high electron mobility. However, the honeycomb structure makes it a material with zero bandgap. Researchers have found a lot of ways to open the bandgap for further applications. Among all of the methods, the reduction of graphene oxide through thermal, electrochemical, or other reduction methods is the most well-recognized efficient way to produce bandgap-opened graphene in large scale. However, in the end product, which is called reduced graphene oxide (rGO), there are too many irremovable oxygen functional groups including C-O, C=O, and COOH. These oxygen functional groups worsen its good properties. In recent publications, although some groups have successfully removed most of oxygen functional groups on rGO, Raman analysis showed that there was no way to reconstruct its lattice structure toward graphene despite the removal of oxygen functional groups. Hence, it is crucial to find a way to improve lattice reconstruction of disordered graphene.
In our work, we found that a lattice-matching ordered template underneath disordered oxidized graphene could improve the structure restoration of oxidized graphene though characterizations of μ-Raman spectroscopy (μ-RS) and μ-X-ray photoelectron microscopy (μ-XPS). In the experiment, we oxidized graphene in regions with 1 layer, 2 layer, and 3 layer through oxidation scanning probe lithography (o-SPL). The oxidation process on 1-layer, 2-layer, and 3-layer graphene of o-SPL was made sure to be top-layer oxidation only so that 1-layer o-SPL graphene without a template, with a 1-layer template, and with a 2-layer template were successfully produced. After XPS reduction, if there was no template underneath, the structure of o-SPL graphene got worse. Noticeably, the structure of o-SPL graphene with a template could successfully be restored to approach the structure of pristine CVD graphene.
It is a finding which provides a way to solve the problem of the worsened conductivity of band-gap opened graphene. The preservation of a better structure for rGO can make it deserve the title of “the anticipated candidate for electronics in the next generation.” | en_US |