Figure 4. High on/off ratio bilayer graphene nanoribbon FET.

(a–b), The room temperature (a), switching behavior and (b), transfer characteristics of the narrow bilayer graphene nanoribbon FET at the various back gate voltages (V_DS = 10 mV). V_BG was modulated from 0 to −90 V in steps of 30 V. Inset in (a) shows SEM image of the bilayer graphene nanoribbon FET used in this measurement. (c), I_DS-V_DS output characteristics of the narrow bilayer graphene nanoribbon FET with V_TG varied from 1 to 5 V in steps of 0.5 V (V_BG = −90 V). (d), Relations between the on/off current ratio of monolayer and bilayer GNR FETs before and after application of the vertical electric field. The vertical and horizontal axes indicate that the on/off current ratio before and after the application of the vertical electric field.