A reverse hysteresis effect of graphene transistors with amorphous silicon gate dielectric

In this paper, graphene field effect transistors with amorphous silicon gate dielectric have been fabricated. A reverse hysteresis effect in these transistors is observed at room temperature. This property is different from that of the graphene field effect transistors with SiO2 gate dielectric. After the transfer characteristics of the graphene transistors, the time evolution of drain current of the graphene devices, and the Raman and infrared spectrum of the α-Si are investigated, the reverse hysteresis is attributed to the defects and hydrogen atoms in surface of the amorphous silicon. This result is helpful to understand the hysteresis effect of graphene devices and enhance the reliability of graphene circuits.