Towards single-gate field effect transistor utilizing dual-doped bilayer graphene

In this work, based on experimental possibilities, our first-principles calculations predict a sizeable bandgap opening in bilayer graphene (BLG) by n-doping from decamethylcobaltocene (DMC) and p-doping from functionalized amorphous SiO2 (a-SiO2) gate dielectric. With DMC monolayer on BLG and the maximum O2− on the surface of a-SiO2 gate dielectric, the dual-doped BLG presents a bandgap of 390-394 meV and a Dirac level shift of −59 to −52 meV. The former is very close to the technical requirement of 400 meV, while the latter properly lies in the accessible range of the gate voltage of 300 meV. The high carrier mobility largely remains with the on/off current ratio satisfying the technical requirement of 104−107. The external electric field is not needed in this technique, which avoids a complex fabrication step for preparing a dual-gate structure and a substantial reduction in carrier mobility and on/off current ratio induced by adding an extra gate.