Ambipolar Black Phosphorus MOSFETs With Record n-Channel Transconductance

Ambipolar black phosphorus MOSFETs with record n-channel extrinsic transconductance are reported. The devices consist of multilayer black phosphorus aligned to a local back-gate electrode with 10-nm-thick HfO 2 gate dielectric. Before passivation, devices with 0.3-μm gate length behaved as p-MOSFETs with peak extrinsic transconductance, g m , of 282 μS/μm at V DS = -2 V. After passivation, the same devices displayed the ambipolar behavior, and when tested as n-MOSFETs, had peak g m = 66 μS/μm at V DS = +2 V, and similar devices on the same wafer had g m as high as 80 μS/μm. These results are an important step toward the realization of high-performance black phosphorus complementary logic circuits.