Physical and Electrical Properties of Spray Coating Graphene Films: The Effect of Solution Concentration

Abstract

Graphene nanofilms were deposited by the spray coating method at different concentrations (0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 g) and prepared at 120°C. The prepared nanofilms were characterized in terms of their structural, morphological, optical, and electrical properties. The results confirm the formation of high-purity and high-crystallinity graphene nanofilms with a layered nanosheet morphology. The X-ray diffraction pattern shows the presence of pure graphene with (002) crystal planes. SEM Images show that the intended graphene films are symmetrical with few wrinkles on their surface. The graphene films show semi-transparent behavior with a maximum transmission of 50%. Raman spectroscopy shows that the relative intensity, position, and shape of the G and 2D Raman peaks change with the number of graphene layers. The electrical conductivity increases with temperature, and the conductivity can be further increased depending on the metal or metal oxide functionalization. The electrical conductivity of the graphene film deposited at a concentration of 0.3 g was significantly higher than the values reported for other concentrations. The results of this study suggest that the physical and electrical properties of spray-coated graphene films can be optimized by controlling the solution concentration, which could have potential applications in transparent conductive films.