Multi- and few-layer graphene on insulating substrate via pulsed laser deposition technique

In this paper, multilayer and few layer graphene (FLG) fabricated on fused silica substrate by pulsed laser deposition (PLD) technique without using any catalyst is reported. The effect of deposition temperature onto the formation of graphene layers is investigated. Raman spectra showed the characteristic features of sp2 bonded carbon atoms; G band, D band and 2D band. The line shape of 2D band structure and the relative intensities of G and 2D bands were used to estimate the number of graphene layers. The graphene layers deposited via PLD at room temperature has I-2D/I-G ratio similar to 0.33, confirming the formation of multilayer whereas that of deposited at substrate temperature 700 degrees C is similar to 0.47 confirming the formation of less than five layers of graphene; few layers graphene. The decrease in separation of subpeaks of 2D band with deposition temperature further confirms the reduction in the number of layers of graphene from similar to 10 deposited at room temperature to less than 5 layers at that of 700 degrees C. The surface morphology of the deposited samples was recorded by field emission scanning electron microscope and transmission electron microscope. (C) 2014 Elsevier B.V. All rights reserved.