Laser direct patterning of a reduced-graphene oxide transparent circuit on a graphene oxide thin film

In this study, reduced-graphene oxide (GO) circuits were directly patterned on glass using an industrially available excimer laser system. A threshold of laser energy density was observed, which provided a clear differentiation on whether the GO was reduced. A sharp drop of resistance by a factor of 104 was measured as the laser energy density increased from 65 to 75 mJ/cm2. The highest conductivity measured was ∼1.33 × 104 S/m, which is among the best reported in the literature for any laser reduction method. Raman analysis of the excimer laser-reduced GO film revealed the formation of a prominent 2D peak at 2700 cm−1. The relative signal strength between the Raman D and G peaks suggests that the amount of structural disorder in the reduced GO is insignificant. The reduced GO displays a transmittance greater than 80% across the entire range from 450 to 800 nm. The outstanding electrical, optical, and morphological properties have enabled graphene to display promising applications, and this nano-processing method makes graphene even more attractive when used as a transparent electrode for touch screens and in many more applications.