Effect of Pulsed Laser on Deposition of Graphene Layers on Silicon (N-P) Substrates and Studying their Physical Properties: An Experimental Study

In this research, the effect of a pulsed laser at 100 pulses was studied on graphene layers deposited on n-type and p-type silicon substrates using spin coating technique. The effect of laser pulses on the reduction of graphene layers was observed, which was clearly demonstrated in AFM images, where a decrease in the thickness of the graphene layer was observed after laser treatment. From XRD results of the samples before and after treatment, a noticeable decrease in the intensity of graphene after exposure to laser pulses appeared. FESEM images of graphene samples deposited on silicon (N-P) substrates are also shown. The samples appear as scattered wrinkled flakes with a crystalline size ranging from (98-78) nm. After laser irradiation, the wrinkled flakes appear in smooth layers evenly distributed on the surface, with the crystalline size decreasing to (66-54) nm. FTIR spectra show vibrational groups of graphene including carbonyl (C=O), aromatic (C=C), carboxyl (COOH), epoxy (CO-C), and hydroxyl (OH) groups” it should be “carbonyl (C=O), (C=C), carboxyl (COOH), epoxy (CO-C), and hydroxyl (OH) groups. Photoluminescence spectroscopy was also used to calculate the energy gap, and its value was observed to decrease after laser irradiation. These results are important for optoelectronic devices due to the distinctive properties resulting from the reduction of the graphene layers obtained. FESEM images of graphene samples deposited on silicon (N-P) substrates are also shown. The samples appear as scattered wrinkled flakes with a crystalline size ranging from (98-78) nm.