Direct comparison of ohmic contact properties between graphene and metal source/drain electrodes

In this study, we directly compared the Ohmic contact properties between graphene and Ag source/drain (S/D) electrodes at the exactly same MoS2 FET device. In order to compare Ohmic contact properties of graphene and Ag electrodes on the same MoS2 nanoflake, graphene S/D electrodes were fabricated on MoS2 active channel and the electrical properties were investigated as a first group. After then, the graphene electrodes were fully covered by Ag S/D electrodes as a control group. Although graphene and Ag have similar workfunctions of similar to 4.5 eV, the graphene S/D FET shows higher ON and lower OFF drain current (I-ON/I-OFF of similar to 10(6)) than that of Ag S/D FET (I-ON/I-OFF of similar to 10(2)), which comes from the Fermi energy level modulation effect of graphene. In addition, the non-classical asymmetric transistor was investigated by constructing the graphene as a source and Ag as s drain in MoS2 FET application, and it showed the gate tunable diode-like behavior and the excellent maximum photo-sensitivity of similar to 10(5) under the green light (520 nm) as well.

Automated summary

This study compares the Ohmic contact properties between graphene and Ag electrodes and finds that graphene electrodes show better performance. Moreover, a non-classical asymmetric transistor constructed with graphene and Ag electrodes demonstrates excellent photo-sensitivity.