Fig. 3
TEM analysis of a CVD-grown graphene flake from ethanol prepared with 4-h growth time, taken from Fig. 2b. High-resolution TEM image showing both monolayer and bilayer regions separated by marked line. Monolayer region contains some defects, which is localized. Moiré patterns as a result of rotational misalignment of the two graphene layers are clearly seen in the bilayer region. The right and left panels of the TEM image display the Fourier transform of the electron diffraction patterns of 1L and 2L graphene. Hexagonal selected area electron diffraction patterns of the monolayer and bilayer graphene reveal the nice crystallinity. Their representative Raman spectra are illustrated in the bottom panel with I2D/IG ratio of 1.88 and 1.26 for 1L and 2L, respectively