Fabrication of Conductive Contact on Graphene Monolayers via Direct Ink Writing

This study investigates the formation of conductive contacts directly on graphene monolayers using direct ink writing (DIW). A glass substrate coated with a graphene monolayer was patterned using femtosecond laser ablation to create test lines with $200 \mu \mathrm{~m}$ width. Silver paste was deposited on the patterned graphene using DIW and then sintered at $60^{\circ} \mathrm{C}$ in ambient air. The electrical properties of the resulting heterostructure were characterized by resistance, impedance, and current-voltage (I-V) measurements. The results showed that the silver-graphene interface exhibits ohmic behavior, with linear I-V characteristics and negligible effect on the conductivity of the graphene pathways. The measured resistivity values were consistent with lower values than theoretical expectations. This study demonstrates that the combination of femtosecond laser patterning and DIW provides an efficient approach to forming reliable electrical contacts for graphene-based devices, potentially as a pathway for applications in flexible electronics and sensors.