Electrical interconnections are one of the main challenges in the printed electronics, to connect different functional units of anelectronic device. With the progressive advancement of large area and low cost printed electronic devices, the requirement forreliable interconnections with lower power consumption fabricated at low temperature is necessary. The conventional copperbased interconnections suffer severe problems in terms of cost efficiency when they are processed with photolithographytechnique. Therefore, there is being a copious amount of re-search to find alternative interconnect materials to overcome suchproblems. Recently, carbon nanotubes (Kordás et al. 2006), silver nanowires (Liu et al. 2011) and graphene (Huang et al. 2011)are being developed as the alter-native interconnection materials. Among them, graphene has high potential for suchapplication due to its remarkable inherent properties: high electrical conductivity, high transparency, mechanical flexibility,higher tensile strength, higher thermal conductivity, extremely high surface area and higher electron mobility. In spite of thoseexcellent properties, graphene has some shortcomings which are needed to be solved. Stacking of graphene sheets issues largeinterface resistance, which is responsible for poor electrical performance. Printing of graphene proved to be a promisingapproach since it combines the attractive features of graphene and the cost effective printing methods (ink-jet printing, nozzleprinting, spray printing) which enable additive patterning, direct writing, scalability to large area manufacturing. In order tofacilitate the printing process, the graphene solution needs to be highly stable, uniform and should contain smaller sheet sizes (~1μm). In this work we have proposed a cost-effective approach for large-scale production of printable stable graphene solutionto be used for the printing of inter-connects. The liquid-phase shear exfoliation (Paton, et al. 2014) of graphite allowed us toprepare large-scale production of solution with exfoliated graphene sheets. The process is scalable and requires shorterprocessing time compared to the other existing exfoliation methods. We have exfoliated graphene sheets from graphite flakesusing environmental-friendly solvent, ethanol, and a stabilizing polymer, ethyl cellulose (EC). The ethyl cellulose was used inorder to encapsulate graphene sheets in the solution and to avoid any reversible process (Secor, et al. 2013). The graphenebased solution prepared after several optimizations of the shear-mixing process leads to a stable solution for more than threemonths without any sedimentation. The microscopic studies of the films prepared from the spin-coating of the solution showedgraphene sheets without any agglomeration and with sheet sizes < 1μm. The process allowed us to prepare a cost-effectivegraphene solution which can be used for producing electrical interconnections by various printing methods.
Graphene exfoliation; shear-mixing; interconnections; graphene ink.