Characterization of nanocarbon deposited on insulator substrate by alcohol chemical vapor deposition

Single-layer-graphene-like nanocarbon materials were directly deposited on c-plane sapphire substrates by thermal chemical vapor deposition with ethanol as a carbon source. Scanning electron microscopy (SEM) images show that the deposited materials have sheetlike grains of around 100 nm diameter. Most of them have "hills with 32 nm diameter on the grains. According to atomic force microscopy (AFM) observation, the height of the sheetlike grains is below 1 nm, which is comparable to that of single-layer graphene, while the hills have a height of several nm. Raman spectra show that the material is similar to graphitic nanocarbon, which has a strong D band. This result implies that there are a number of defects in the nanocarbon materials.