Graphene Nanosheets Prepared by Arc Discharge Method and Their Application in Conductive Inkjet

Conductive ink is one of the dominant electronic materials for printed electronics technology. As the main component in conductive inks, conductive fillers are required to have favorable electronic properties and good chemical stability. Up to date, graphene-based conductive ink has attracted enormous research interest mainly due to its remarkable electrical properties. In present study, the graphene sheets as the conductive fillers were fabricated via a direct current arc discharge evaporation method. Furthermore, the as-prepared graphene sheets were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectra analysis. The results demonstrated that the graphene sheets consisting of 2-10 layers with sheet size ranging from 100 nm to 200 nm had high purity and high crystallinity. Besides, the relationships between conductive properties and coating thicknesses, annealing temperatures and bending angles of conductive ink, were also carried out. It was found that the resistivity of conductive ink was inversely proportional to its thickness and annealing temperature, i.e. with gradual increase in thickness and temperature, the resistivity was decreased. And the resistivity of the conductive ink on the flexible substrate remained stable under different folding angles. Specially, the conductive ink with a thickness of 170 mu m achieved the specific resistivity of 0.003 Omega.cm after being annealed at 360 degrees C for 30 min. The results indicate that arc-discharge graphene sheets are promising alternative for next generation of printed electronics.