We report on our joint spectroscopic study of the thermal reduction process of quasi-monolayer graphene oxide films grown on fused silica substrates by spin-coating. We estimate that about 65 of our film area consists of monolayer platelets of reduced graphene oxide, based on our quantitative analysis of the local atomic force microscopy topography. With thermal annealing under suitable conditions, clear signatures of monolayer graphene behavior were identified in the resonant excitonic absorption at 4.55 eV, the overall decrease in the visible-range transmission, the re-emergence of the Raman 2D band, the red-shift of the Raman G band toward the monolayer position, and the decrease in the optical sheet resistance in the terahertz range.
Bibliographical noteFunding Information:
This work was partially supported by the Pioneer Research Center Program (2010-0019313), the Priority Research Centers Program (2009-0093823), and the Nano Material Technology Development Program (2012M3A7B4049802) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)