where λl is the exciting laser wavelength, nm, and ID and IG
are integral intensities of the D and G bands, respectively.
Calculation of graphene crystallite sizes using formula (1)
yielded LG=33 and 16 nm for the samples the ID/IG ratio
of which is shown in Table 1. In our opinion these values are
overestimated but yet can be used for comparison of
different samples.