| 초록 |
We fabricated vertical Schottky barrier(SB) transistors based on graphene–organic semiconductor(p-type pentacene or n-type PTCDI-C8) heterostructures. The Schottky barrier at this vertical heterojunction could be modulated by tuning the gate bias. Molecular dopants (p-type TFSA or n-type PEI were inserted underneath the graphene layer, which we refer to as the underside-doping method. This method enabled tuning the work function of the graphene maintaining the surface properties of the graphene electrodes, unlike when the dopants were placed on top of the graphene. This charge injection at the heterojunction and the vertical transistor performances, including the device current density and on-off ratio, varied with doping the graphene electrode. The optimized p- and n-type devices yielded a high current density of 11 mAcm–2 and a high on-off current ratio of ~103. Complementary inverters were successfully fabricated by assembling the p-type and n-type vertical SB transistors. |
