A study on 3D graphene synthesized directly on Glass/FTO substrates: Its Raman mapping and optical properties

In this study, vertically oriented (3D) graphene nanostructures (VGN) were obtained on Glass and Fluorine doped tin oxide (FTO) substrates at relatively low temperatures (approaximatelly at 400 °C) by using plasma enhanced chemical vapor deposition (PECVD) technique. VGNs were characterized using Raman, Uv–Vis and SEM spectroscopies, respectively. Raman spectroscopy showed that growth temperature significantly affected VGN formation and film quality. The layer structures of these VGNs were also confirmed by Raman mapping. The most important data obtained from this study is that although the applied radio frequency (RF) power is the same, the growth temperature significantly affects the graphene formation and morphologies. This was attributed to the fact that CH4 decomposition was very difficult at low temperatures. The optical transmittance of VGNs ranged from 50% to 95% (at 550 nm wavelength) and their electrical conductivity was also determined to be between 5.94 kohm/sqr and 11.2 kohm/sqr. The electrical and optical properties of VGNs, which have a large surface area, indicated that they may be an alternative material for sensor, solar cell and supercapacitor applications.