Solution-processable organic dielectrics for graphene electronics

We report the fabrication, at low-temperature, of solution processed graphene transistors based on carefully engineered graphene/organic dielectric interfaces. Graphene transistors based on these interfaces show improved performance and reliability when compared with traditional SiO ₂ based devices. The dielectric materials investigated include Hyflon AD (Solvay), a low-k fluoropolymer, and various organic self-assembled monolayer (SAM) nanodielectrics. Both types of dielectric are solution processed and yield graphene transistors with similar operating characteristics, namely high charge carrier mobility, hysteresis free operation, negligible doping effect and improved operating stability as compared to bare SiO ₂ based devices. Importantly, the use of SAM nanodielectrics enables the demonstration of low operating voltage (<|1.5|V), solution-processable and flexible graphene transistors with tunable doping characteristics through molecular engineering of the SAMs molecular length and terminal group. The work is a significant step towards graphene microelectronics where large-volume and low-temperature processing are required.