Disorder induced bands in first order Raman spectra of carbon nanowalls

Raman spectra of carbon nanowalls grown by microwave plasma enhanced chemical vapor deposition were analyzed. A typical Raman spectrum of carbon nanowalls exhibits three main bands, i.e., the G, D and D’ bands centered at about 1580, 1350 and 1620 cm^-1, respectively. The peak intensity ratio of D to G band (ID/IG) was found to be strongly influenced by edge length density of carbon nanowalls, suggesting that the strong D band is originated from the defects at the edges. The addition of water during the growth process increased the defects formed by water assisted oxidization which in turn, resulted in the increase of the D band’s relative intensity.